biology - Manuel Tellez

Transcription

BIOLOGY I
And overview of Biology: The Nature of Science
and Biology
BIOLOGY: THE SCIENCE OF OUR LIVES


Tellez Carmona José Manuel

Biology literally means "the study of life". Biology is such a
broad field, covering the minute workings of chemical
machines inside our cells, to broad scale concepts of
ecosystems and global climate change.
Biologists study intimate details of the human brain, the
composition of our genes, and even the functioning of our
reproductive system.
Biologists recently all but completed the deciphering of the
human genome, the sequence of deoxyribonucleic acid
(DNA) bases that may determine much of our innate
capabilities and predispositions to certain forms of behavior
and illnesses. DNA sequences have played major roles in
criminal cases (O.J. Simpson, as well as the reversal of
death penalties for many wrongfully convicted individuals),
as well as the impeachment of President Clinton (the stain
at least did not lie).
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

We are bombarded with headlines about possible
health risks from favorite foods (Chinese,
Mexican, hamburgers, etc.) as well as the
potential benefits of eating other foods such as
cooked tomatoes.
Informercials tout the benefits of metabolismadjusting drugs for weight loss. Many people are
turning to herbal remedies to ease arthritis pain,
improve memory, as well as improve our moods.
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Can a biology book give you the answers to these
questions? No, but it will enable you learn how to sift
through the biases of investigators, the press, and others in
a quest to critically evaluate the question.
To be honest, five years after you are through with this
class it is doubtful you would remember all the details of
metabolism.
However, you will know where to look and maybe a little
about the process of science that will allow you to make an
informed decision.
Will you be a scientist? Yes, in a way. You may not be
formally trained as a science major, but you can think
critically, solve problems, and have some idea about what
science can and cannoit do.
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DIAGNOSTIC ASSESSMENT
YOU WILL HAVE ONLY 12 MINUTES TO DELIVER IT…
IT DOESN’T COUNT FOR YOUR THIS PARTIAL GRADE, BUT IF YOU DO NOT
HAVE ENOUGHT SERIOUSNESS YOU WILL LOST 5 FINAL PARTIAL POINTS…


Contesta lo que a continuación se te indica.
What theories and biological principles do you know?
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Why Biology is considered a scientific area?
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How many different study areas of Biology do you know? What do you know
about them?

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Write at least 5 examples of Biology applications in your all-day life.
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How many kinds of microscopes do you know or heard about and what is used
for each kind of this? What kind of another lab’s equipment do you know or
heard about and what it is used for?
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THEORIES CONTRIBUTING TO MODERN
BIOLOGY

2.
3.
4.
1.
Modern biology is based on several great ideas, or
theories:
The Cell Theory
The Theory of Evolution by Natural
Selection
Gene Theory
Homeostasis
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CELL THEORY
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Robert Hooke (1635-1703), one of the first scientists to use a
microscope to examine pond water, cork and other things,
referred to the cavities he saw in cork as “cells", Latin for
chambers.
Mattias Schleiden (in 1838) concluded all plant tissues
consisted of cells. In 1839, Theodore Schwann came to a
similar conclusion for animal tissues.
Rudolf Virchow, in 1858, combined the two ideas and added
that all cells come from pre-existing cells, formulating the Cell
Theory.
Thus there is a chain-of-existence extending from your
cells back to the earliest cells, over 3.5 billion years ago.
The cell theory states that all organisms are composed of one
or more cells, and that those cells have arisen from preexisting cells.
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GENE THEORY
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In 1953, American scientist James
Watson and British scientist
Francis Crick developed the
model for deoxyribonucleic acid
(DNA), a chemical that had (then)
recently been deduced to be the
physical carrier of inheritance.
Crick hypothesized the mechanism
for DNA replication and further
linked DNA to proteins, an idea
since referred to as the central
dogma.
Information from DNA "language"
is converted into RNA(ribonucleic
acid) "language" and then to the
"language" of proteins. The central
dogma explains the influence of
heredity (DNA) on the organism
(proteins).
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HOMEOSTASIS THEORY
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Homeostasis is the maintainence of a dynamic
range of conditions within which the organism
can function.
Temperature, pH, and energy are major
components of this concept.
Theromodynamics is a field of study that
covers the laws governing energy transfers, and
thus the basis for life on earth. Two major laws
are known: the conservation of matter and
energy, and entropy. The universe is composed
of two things: matter (atoms, etc.) and energy.
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DARWINIAN EVOLUTION
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
The voyage would provide Darwin a unique opportunity to
study adaptation and gather a great deal of proof he would
later incorporate into his theory of evolution.
On his return to England in 1836, Darwin began (with the
assistance of numerous specialists) to catalog his
collections and ponder the seeming "fit" of organisms to
their mode of existence. He eventually settled on four main
points of a radical new hypothesis:

Charles Darwin, former divinity student and former
medical student, secured (through the intercession of his
geology professor) an unpaid position as ship's naturalist
on the British exploratory vessel H.M.S. Beagle.
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MAIN POINTS OF DARWINIAN EVOLUTION
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Since not all organisms are equally well adapted to their
environment, some will survive and reproduce better than
others -- this is known as natural selection. Sometimes
this is also referred to as "survival of the fittest".
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
Adaptation: all organisms adapt to their environments.
Variation: all organisms are variable in their traits.
Over-reproduction: all organisms tend to reproduce
beyond their environment's capacity to support them (this
is based on the work of Thomas Malthus, who studied
how populations of organisms tended to grow geometrically
until they encountered a limit on their population size).
In reality this merely deals with the reproductive success of
the organisms, not solely their relative strength or speed.
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Alfred Russel Wallace
Charles Darwin
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
To be correct, we need to mention that both Darwin and Wallace
developed the theory, although Darwin's major work was not
published until 1859 (the book On the origin of Species by
Means of Natural Selection, considered by many as one of the
most influential books written [follow the hyperlink to view an
online version]).

In 1858, Darwin received a letter from Wallace, in which Darwin's
as-yet-unpublished theory of evolution and adaptation was
precisely detailed. Darwin arranged for Wallace's letter to be read
at a scientific meeting, along with a synopsis of his own ideas.
While there have been some changes to the theory since 1859,
most notably the incorporation of genetics and DNA into what is
termed the "Modern Synthesis" during the 1940's, most scientists
today acknowledge evolution as the guiding theory for modern
biology.
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DIVERSITY OF LIFE
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DIVERSITY OF LIFE…
SOME EMPLOYED CHACTERISTICS FOR LIVING BEINGS CLASSIFICATION
REINO
Bacteria
Not well defined Procaryotic
yet
Unicellular
Archaea
Not well defined Procaryotic
yet
Protista
Eucaryotic
Unicellular
Absortion
Unicellular
/ Multicellular
Fungi
Eucaryotic
Multicellular
Absortion,
Ingestion
or
Phtotosynthesis
Absortion
Plantae
Eucaryotic
Multicellular
Phtotosynthesis
Animalia
Eucaryotic
Multicellular
Ingestion
Eukarya
TIPO DE
CÉLULAS
NÚMERO DE
CÉLULAS
PRINCIPAL
MODO DE
NUTRICIÓN
Absortion,
Phtotosynthesis
DOMINIO
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WHAT IS LIFE
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A quality that distinguishes a vital functioning being from a
dead body.
A quality that seems to be intangible and not easy to define.
Sustantial internal force or activity that allows you to be or
act.
Activity stage of organic beings.
Soul and Body together.
Period of time that occurs since the birth of an animal or a
vegetable to its death
DEFINITION OF
 It
LIFE
seems that is
difficult to give a
“definition” for
this term

We can not use a
simple definition,
because life is more
than simply the sum
of its parts…. So we
must take advantadge
of this complexity to
understand it….
LIVING
CHARACTERISTICS
LIVING THINGS
THINGS:
OF
Have a complex, organized structure that consists
largely of organic molecules.
 Respond to stimuli from their environment.
 Follow the process of: Homeostasis.
 Acquire and use materials and energy from their
environment and convert it in different forms.
 Grow.
 Reproduce using a molecular blueprint called DNA.
 Have the capacity to evolve.
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Los seres vivos no pueden definirse como la suma de sus partes. La cualidad de la
vida surge como resultado de las increíblemente complejas interacciones
ordenadas de estas partes. Dado que está basado en esas propiedades
emergentes, la vida es una cualidad fundamentalmente intangible, imposible
definir de manera simple. Sin embargo, las características de los seres vivos, son:
1.
4.
5.
6.
7.
2.
3.
Los seres vivos tienen una estructura compleja, organizada, que consta en buena parte de moléculas
orgánicas (niveles de organización, células)
Los seres vivos responden a los estímulos de su ambiente (Órganos sensoriales y sistemas musculares)
Los seres vivos mantienen activamente su compleja estructura y su ambiente interno; este proceso se
denomina homeostasis
Los seres vivos obtienen y usan materiales y energía de su ambiente y los convierten en diferentes formas
(nutrimentos-metabolismo-energía-fotosíntesis-quimiosíntesis)
Los seres vivos crecen (implica la conversión de materiales obtenidos del ambiente para formar las moléculas
específicas del cuerpo del organismo)
Los seres vivos se reproducen, utilizando un patrón molecular llamado ADN (El ADN de un organismo es su
copia genética o su manual de instrucción molécular, una guía para la construcción, y en parte, para el
funcionamiento de su cuerpo)
Los seres vivos, en general y como un todo, poseen la capacidad de evolucionar (los organismos modernos
descendieron, con modificaciones, de formas de vida preexistentes, y que en última instancia, todas las
formas de vida del planeta tienen un antepasado común)
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CHARACTERISTICS OF LIVING THINGS

2. Homeostasis. is the maintenance of a constant (yet also
dynamic) internal environment in terms of temperature, pH,
water concentrations, etc.
Much of our own metabolic energy goes toward keeping within our
own homeostatic limits.
 If you run a high fever for long enough, the increased temperature
will damage certain organs and impair your proper functioning.
 Swallowing of common household chemicals, many of which are
outside the pH (acid/base) levels we can tolerate, will likewise
negatively impact the human body's homeostatic regime.
 Muscular activity generates heat as a waste product. This heat is
removed from our bodies by sweating. Some of this heat is used by
warm-blooded animals, mammals and birds, to maintain their
internal temperatures.
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1. Organization. Living things exhibit a high level of
organization, with multicellular organisms being subdivided
into cells, and cells into organelles, and organelles into
molecules, etc.
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
4. Reproduction and heredity. Since all cells come from
existing cells, they must have some way of reproducing,
whether that involves asexual (no recombination of genetic
material) or sexual (recombination of genetic material).
Most living things use the chemical DNA (deoxyribonucleic
acid) as the physical carrier of inheritance and the genetic
information.
 Some organisms, such as retroviruses of which HIV is a
member), use RNA (ribonucleic acid) as the carrier.
 The variation that Darwin and Wallace recognized as the
wellspring of evolution and adaptation, is greatly increased by
sexual reproduction.


3. Adaptation. Living things are suited to their mode of
existence. Charles Darwin began the recognition of the
marvellous adaptations all life has that allow those
organisms to exist in their environment.
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6. Energy acquisition and release. One view of life is that it is a
struggle to acquire energy (from sunlight, inorganic chemicals, or
another organism), and release it in the process of forming ATP
(adenosine triphosphate).
7. Detection and response to stimuli (both internal and external).

5. Growth and development. Even single-celled organisms grow.
When first formed by cell division, they are small, and must grow and
develop into mature cells. Multicellular organisms pass through a
more complicated process of differentiation and organogenesis
(because they have so many more cells to develop).
8. Interactions. Living things interact with their environment as
well as each other. Organisms obtain raw materials and energy from
the environment or another organism. The various types of
symbioses (organismal interactions with each other) are examples of
this.
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
1. A (an) ____ is any part of an organism's environment that causes a reaction.

A)growth

3. Drip-tip leaves allow plants to live in what kind of environment?

A)tropical

4. Which of these is not an example of the body maintaining homeostasis?

A)red blood cells delivering oxygen
C)lungs absorbing oxygen

5. Which of the following constitutes the basic structural organization of life?

A)weather conditions in a habitat
B)cell organelles that combine to form nuclei
C)species living in an environment D)cells that make up tissues and structures
B)development
B)windy
C)response D)adaptation3
C)cold
D)desert4
B)emergence of an evolutionary adaptation
D)insulin production in the pancreas5

A)species
B)adaptation
C)stimulus D)organization
2 The process of natural changes that take place during an organism's life is called ____.

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RELATIONSHIPS ON BIOLOGY
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INTERDISCIPLINARY
Paleontology
Biology
History
Math
Physics
Biostatistics
Chemistry
Biodynamics
Biophysics
Bionycles
Biochemistry
Biopolymers
Biomass
Anthropology
Pathology
Physiology
Morphology
Anatomy
Taxonomy
Biomedicine
Medicine
Zoology
Biogenetics
BIOLOGY
Botanics
Ethology
Ecology
Embriology
Cryobiology
Citology
Exobiology
Geology
Earth SciencesAgriculture
Biophysics
Biotechnology
Microbiology
Biogeography
Next slide: Important scientists in biology.
 Remember you should know what they did.
 There are some names highlighted.

Important Scientists in Biology
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•
•
Robert Hooke
Alexander von Humboldt
John Needham
Edward Jenner
Jean Baptiste de Lamarck
Gottfried Reinhold Treviranus
Karl Friedrich Burdach
Robert Brown
Rudolf Virchow
Lynn Margulis
Matthias Jakob Schleiden
Paul Ehrlich
Ernest Haeckel
Ernest Mayer
Robert Whittaker
William Smith
Charles Lyell
Christian Gram
Robert Briggs
Alexander Oparin
Francis Crick
James Watson
•
•
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•
•
•
•
•
•
•
•
Rosalind Franklin
Gregor Mendel
Carl von Linné (Carlos Linneo)
Ernst Haeckel
Georges Louis Leclerc, Conde de
Buffon
Georges Cuvier
Carl Woese
S.J. Singer & G.L. Nicolson
Melvin Calvin & Andy Benson
Hans Adolf Krebs
Camillo Golgi
Harold Urey & Stanley Miller
John Tyndall
Carl Woese
Linus Pauling
James Hutton
George Beadle
Alexander Fleming
Louis Pasteur
Francesco Redi
Charles Darwin
Develop and
Growing of Living
Beings
Morphophysiologic
caracteristics of
living beings
aplicación de
conocimientos
biológicos a nivel
personal
Genetics and living
beings
interbreeding
Evolutive
relationships
among different
groups of
organisms
Genetic
engineering
Earth´s origin of
life
Biotecnology
Exobiology
Rivers and basins
Studyng and
conservation
Agricultural
research
Seas study and
conservation
Cattle raising
research
Biología:
examples
Biomedical
research
Aquariums,
Forests and jungles
Veterinary
research
Natural History
Museums
Piscicultura
Zoologics
Aviculture
Apiculture
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INTERDISCIPLINARY RELATIONSHIPS OF
BIOLOGICAL SCIENCES
In accord of Taxonomic criterium, they group together as:

Zoología (Zoology). Animal studies

Botánica (Botany). Plants studies

Micología (Micology). Mushrooms studies

Protozoología (Protozoology). Protozoans studies

Bacteriología (Bacteriology). Bacteria studies
Sub-branches
Implies
Mastozoology
Mammals
Ornitology
Birds
Herpetology
Anphibians and reptiles
Ictiology
Fishes
Entomology
Insects
Carcinology
Crustaceans
Malacology
Moluscs
Helmintology
Planes and cylindric worms

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Etología
(caracter y
comportamien
to)
Micología
(hongos)
Anatomía
(organos,
aparatos,
sistemas)
Botánica
(plantas)
Fisiología
(funciones)
Embriología
(formación y
desarrollo de
los embriones)
Zoología
(animales)
Bacteriología
(bacterias)
Principales
ramas
biológicas y su
campo de
estudio
Protozoología
(protozoarios)
Genética
(variaciones y
herencia)
Ecología
(interrelacion
es seres vivosambiente)
Taxonomía
(clasificación
de los seres
vivos)
Patología
(enfermedade
s)
Ficología
(algas)
Paleontología
(fósiles)
Histología
(tejidos)
Evolución
(origen y
cambios en
las especies)
Ingeniería
genética
(organismos y
productos
transgénicos)
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CONTINUITY REFERS TO LIVING BEING´S CAPACITY OF REPRODUCTION.
THE MAIN BIOLOGY´S BRANCHES ARE DESCRIBED BELOW:
Field of study
Biological inheritance and variations
Origin and change of organisms
Living beings functions
Organs and systems description
Tissues
Cells
Embrio´s development
Fossils and organisms origin
Interrelationship between abiotic and biotic factors
Living beings classification
Temperament and behaviour
Branch
Genetics
Evolution
Phisiology
Anatomy
Histology
Citology
Embriology
Paleontology
Ecology
Taxonomy
Etology
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Ciencias de
la Tierra
(origen y
evolución de
la Tierra)
Ciencias de
la salud
(previene y
trata
problemas
de salud
humana
Ética
(principios y
valores de
conducta)
Etnología
(las razas
humanas)
Principales
ciencias que
interactuan
con la
Biología
Antropologí
a (al ser
humano)
Sociología
(leyes y
fenómenos
sociales)
Lógica
(proporciona
bases para
el
razonamient
o científico)
Matemática
s
(estadística,
probabilidad
es,
porcentajes,
etc.)
Historia
(aporta
datos que
contribuyen
al estudio de
la Biología)
Geografía
(origen,
estructura y
evoluón de
la Tierra)
Química
(cambios y
reacciones
de la
materia
viva)
Física
(relación
entre
materia y
energía)
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SCIENCE AND
THE SCIENTIFIC
METHOD
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SCIENCE AND THE SCIENTIFIC METHOD



Good science is not dogmatic, but should be viewed as an ongoing
process of testing and evaluation. One of the hoped-for benefits of
students taking a biology course is that they will become more
familiar with the process of science.
Humans seem innately interested in the world we live in. Young
children drive their parents batty with constant "why" questions. S
Science is a means to get some of those whys answered. When we
shop for groceries, we are conducting a kind of scientific experiment.
If you like Brand X of soup, and Brand Y is on sale, perhaps you try
Brand Y. If you like it you may buy it again, even when it is not on
sale. If you did not like Brand Y, then no sale will get you to try it
again.

Science is an objective, logical, and repeatable attempt to understand
the principles and forces operating in the natural universe. Science is
from the Latin word, scientia, to know.
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LA BIOLOGÍA SE DEDICA AL ESTUDIO DE LOS SERES
VIVOS Y TODO LO QUE CON ELLOS SE RELACIONA.
CARACTERÍSTICAS DE LA CIENCIA
CONSTRUCCIÓN DEL CONOCIMIENTO (a partir de la reactivación de los conocimientos previos)
Elementos que lo integran
Características
Sujeto cognoscitivo
Es la persona que capta ideas o juicios referentes a algún
aspecto de la realidad mediante su capacidad cognoscitiva
Objeto del conocimiento
Es la cosa o ente conocido. Existe cierta correlación entre el
sujeto del conocimiento y el objeto que puede llegar a
modificar los pensamientos del sujeto
Operación cognoscitiva
Proceso psicofisiológico que pone en contacto mediante
pensamientos al sujeto con el objeto.
Pensamientos
Expresiones mentales de los objetos conocidos. Cada objeto
que se conoce, deja huellas en la memoria del sujeto
Característica
Porque
Objetiva
Trata de alcanzar la verdad y describir los hechos, incluso
produciendo nuevos hechos para reforzar las explicaciones
Racional
Porque investiga para adquirir conocimientos y aplica la
lógica para establecer las relaciones que existen entre
diferentes hechos.
Verificable
Como los conocimientos científicos son objetivos, pueden ser
verificados en cualquier momento y en cualquier parte del 36
mundo porque la ciencia es universal.



Which is precisely what one does with some computer
or videogames (before buying the cheatbook).
The scientific method is to be used as a guide that
can be modified. In some sciences, such as taxonomy
and certain types of geology, laboratory experiments
are not necessarily performed.
Instead, after formulating a hypothesis, additional
observations and/or collections are made from
different localities.

In order to conduct science, one must know the rules
of the game (imagine playing Monopoly and having to
discover the rules as you play!
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STEPS IN THE SCIENTIFIC METHOD
COMMONLY INCLUDE:
Observation: defining the problem you wish to
explain.
 Hypothesis: one or more falsifiable explanations
for the observation.
 Experimentation: Controlled attempts to test
one or more hypotheses.
 Conclusion: was the hypothesis supported or
not? After this step the hypothesis is either
modified or rejected, which causes a repeat of the
steps above.

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WATCH THE SCIENTIFIC METHOD MOVIE…
After a hypothesis has been repeatedly tested, a hierarchy
of scientific thought develops.

Hypothesis is the most common, with the lowest level of
certainty.

A theory is a hypothesis that has been repeatedly tested
with little modification, e.g. The Theory of Evolution.


A Law is one of the fundamental underlying principles of
how the Universe is organized, e.g. The Laws of
Thermodynamics, Newton's Law of Gravity.
Science uses the word theory differently than it is used in
the general population. Theory to most people, in general
nonscientific use, is an untested idea. Scientists call this a
hypothesis.

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

A good science experiment does not
simultaneously test several variables, but rather
a single variable that can be measured against a
control.
Scientific controlled experiments are situations
where all factors are the same between two test
subjects, except for the single experimental
variable.

Scientific experiments are also concerned with
isolating the variables.
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SCIENTIFIC PRINCIPLES
1.
3.
2.
TODA INVESTIGACIÓN CIENTÍFICA SE APOYA EN PRINCIPIOS CIENTÍFICOS
La causalidad natural es el principio de que todos los sucesos tienen causas naturales. Por ejemplo,
en otros tiempos se pensó que la epilepsia era consecuencia de una disposición divina. Hoy se sabe
que es una enfermedad del cerebro en la que grupos de células nerviosas se activan de manera
incontrolable. No hace mucho había quien argumentaba que los fósiles no son prueba de la evolución,
sino que Dios los colocó en la Tierra para poner a prueba nuestra fe. Si no podemos confiar en las
pruebas que nos proporciona la Naturaleza, la ciencia se convierte en un empeño futil…
Las leyes naturales que rigen los sucesos son válidas en todo lugar y en todo momento. Las leyes de
la gravedad, el comportamiento de la luz y las interacciones de los átomos, son las mismas ahora que
hace mil millones de años y se cumplen tanto en Moscu como en Nueva York, o incluso Marte.
La uniformidad en el espacio y el tiempo resulta especialmente indispensable en Biología, porque
muchos hechos ocurrieron antes de que hubiera seres humanos para observarlos. Hay quienes creen
que cada uno de los diferentes tipos de organismos fue creado individualmente en algún momento
del pasado por intervención directa de Dios, filosofía que se conoce como Creacionismo. No se puede
demostrar que tal idea es falsa, no obstante, el creacionismo se opone tanto a la causalidad natural
como a la uniformidad en el tiempo.
La investigación científica se basa en el supuesto de que las personas perciben los sucesos naturales
de forma similar. Todos los seres humanos perciben los sucesos naturales básicamente de la misma
manera y que esas percepciones nos proporcionan información confiable acerca del mundo que nos
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rodea. No se puede decir lo mismo de los sistemas de valores, ya que son subjetivos, no objetivos, y
por tanto, la ciencia no puede resolver ciertos tipos de problemas filosóficos o morales, como la
moralidad del aborto.
YOU ARE CAMPING AND YOU GO TO TURN ON
YOUR FLASHLIGHT AND IT DOESN’T WORK. SO
WHAT IS WRONG WITH IT?







You will use scientific
"hypothetical-deductive reasoning"
to decide.
Hypothesis: Maybe the batteries are
dead?
Prediction: If we change the
batteries with fresh ones the
flashlight should work.
Experiment to test that hypothesis:
we replace the batteries.
Results: Well if it was the batteries
then the flashlight should work.
If it wasn’t the batteries then we
need to formulate a new hypothesis
and test it.
A good hypothesis allows us to
make predictions, the "if …then"
statement. "If the batteries are
dead, then replacing them will
make the flashlight work".
42
COLLABORATIVE ACTIVITY 1. WORKING
DEEP INSIDE SCIENCE








Stand up and make up a team of 3
You will only have 15 minutes to get the job ready!
Between all the members of the team will have to generate a
brainstorm and to choose one example (like the last one!) (4 minutes)
Rol 1: One person in the team has to generate a different template,
like the last slide example, showing the different steps of the
scientific method (the template or draft it’s just a papersheet in which
you will draw and write your example)
Rol 2: another has to take the time (time keeper) and to visit other
teams for to get ideas and for to not repeat the same example! (5
minutes)
Rol 3: the next guy will help in the elaboration of the final draft and
will explain it to all the whole group (2 minutes to deliver it)
The final result will be delivered to the teacher at the the end of the
class in a like- lab’s report papersheet
The last team to deliver their job will be the only one in to expose to
the rest of the class, otherwise will be a kind of fairy elected team
picking up a piece of paper of a plastic bag… (4 minutes to expose it)
43
LEVELS OF
ORGANIZATION
Ecological levels…
44
From sub particles to
HOMEWORK
Everyone have to read the next article called
Biological complexity and integrative levels or
organization
 We will discuss the topic two classes ahead… It
will be like a brief exam, so If you do not answer
the questions or discuss about the article, you
will be losing points in your grading…
 Link:
https://docs.google.com/document/edit?id=15Evdt
OkzqebeH0x1mqYngf5gD0wKw9JsE2iKeICuYU
M&hl=en&authkey=CPaI8ocN

45
LEVELS OF ORGANIZATION
CHEMICAL LEVEL: ATOMS TO BIOMOLECULES
Atoms
Most of the Universe consists of matter and energy.

Energy is the capacity to do work.

Matter has mass and occupies space.

All matter is composed of basic elements that cannot be broken
down to substances with different chemical or physical properties.


Elements


are substances consisting of one type of atom,
for example Carbon atoms make up diamond, and also
graphite. Pure (24K) gold is composed of only one type of
atom, gold atoms. Atoms are the smallest particle into
which an element can be divided.
46
PROTONS
The proton is located in the center (or nucleus) of an atom,
each atom has at least one proton.

Protons have a charge of +1, and a mass of approximately 1
atomic mass unit (amu).

Elements differ from each other in the number of protons they
have, e.g. Hydrogen has 1 proton; Helium has 2.

47

The neutron
also is located in the atomic nucleus (except in Hydrogen).
The neutron has no charge, and a mass of slightly over 1
amu.
 Some scientists propose the neutron is made up of a proton
and electron-like particle.

The electron
is a very small particle located outside the nucleus.
Because they move at speeds near the speed of light the
precise location of electrons is hard to pin down.
 Electrons occupy orbitals, or areas where they have a high
statistical probability of occurring.
 The charge on an electron is -1. Its mass is negligible
(approximately 1800 electrons are needed to equal the
mass of one proton).



48
TABLE 1. SUBATOMIC PARTICLES OF USE
IN BIOLOGY.
49


The atomic mass (also referred to as the atomic
weight) is the number of protons and neutrons in an
atom. Atoms of an element that have differing
numbers of neutrons (but a constant atomic number)
are termed isotopes.
Biochemical pathways can be deciphered by using
isotopic tracers.
The age of fossils and artifacts can be determined by using
radioactive isotopes, either directly on the fossil (if it is
young enough) or on the rocks that surround the fossil (for
older fossils like dinosaurs).
 Isotopes are also the source of radiation used in medical
diagnostic and treatment procedures.

The atomic number is the number of protons an atom
has. It is characteristic and unique for each element.

50
51
MOLECULES EXAMPLES…
52
CHEMICAL REACTION
53
CELLULAR LEVELS OF ORGANIZATION
Cells: microscopic units of living matter
 Each individual begins as a single cell that is
capable of mitosis and differentiation


As a consequence of mitosis and differentiation, four cell
groups develop
At the cellular level we find the above biomolecules
associated with one another to form complex and highly
organized and highly specialized structures within the
cell called "organelles". These sub-cellular organelles
are each designed to perform specific functions within
the cell.

54

"The cell" itself is the basic structural and
functional unit of life.

Tissues:


Organs:


In most multicellular organisms cells, associate to form tissues,
such as muscle tissue or nervous tissue.
Tissues are arranged into functional structures called organs,
such as the heart or stomach.

The cell is the smallest and simplest part of living matter that
can carry on all the activities necessary for life. Each cell
consists of a discrete body of jelly-like cytoplasm surrounded by
a cell membrane. The organelles are suspended within the
cytoplasm.
Organ Systems:

Each major group of biological functions is performed by a
coordinated group of tissues and organs called an organ
system. The "circulatory and digestive system" are examples of
organ systems.
55
56
ECOLOGICAL LEVELS OF ORGANIZATION

The Organism

Populations


Community


All the members of one species that live in the same area make up
a population.
The population of organisms that inhabit a particular area and
interact with one another form a community. Thus a community can
be comprised of hundreds of different types of life forms. The study of
how organisms of a community relate to one another and with their
non-living environment is called "ecology".

Functioning together with great precision, the organ systems make up
the complex multicellular organism. Organisms interact to form still
more complex levels of biological organization.
Ecosystem

A community, together with its non-living environment is referred to
as an "ecosystem". An ecosystem can be as small as a pond (or even a
puddle) or as vast as the great plains of North American or the Arctic
tundra.
57

Ecosystem

The largest ecosystem
is the plant Earth
with all its
inhabitants - "The
Biosphere".
58
59
CHEMICAL BONDS
CHEMICAL BONDS; THE "GLUE" THAT
HOLDS MOLECULES TOGETHER.


Atoms are "most stable" when their outermost orbitals are filled.
Two hydrogen atoms, each of which has one electron, can "share" the
electrons so that each effectively has two electrons ion the 1s orbital.
Thereby completing it and establishing the most stable arrangement.
As the atoms approach each other, each nucleus begins to attract the
electron held by the other nucleus. Eventually, the electron clouds
overlap and fuse into one "molecular orbital". Like an atomic
orbital, a molecular orbital is most stable when filled by a pair of
electrons. This shared orbital acts ad a "chemical bond" between
the two atoms and resembles a strong "spring", in its properties. It
can be compressed, stretched and bent to a certain extent without
breaking, it can also spin like and axil or vibrate.

Hydrogen "H" usually exists as the molecule (H2). A hydrogen
molecule is more stable than two hydrogen atoms, therefore, energy
must be expended in order to "break" the hydrogen molecule into its
component atoms.
60

One biologically important element that hydrogen can also
bond to is carbon.


Carbon has a total of six electrons. Two in its 1s orbital and four
electrons in the outermost (second) orbital. This second energy
level (orbital) can accommodate a maximum of eight electrons.
Therefore, carbon is looking for four additional electrons to fill its
2p orbitals, and give it maximum stability.
The unfilled orbitals of four hydrogen can form four covalent
bonds by a sharing of pairs of electrons between carbon and
hydrogen.

An atom can form as many bonds as there are unpaired
electrons in its outermost orbital. The bond between two
atoms of hydrogen is called a "covalent bond".
61
Covalent bonds
Double covalent bonds
The kinds of bonds in methane (CH4) are "single
bonds", meaning only one pair of electrons is shared
between two atoms. But two atoms can share two or
three pairs of electrons forming "double or triple"
bonds. Carbon atoms often form double bonds. For
example Ethylene.
62
IONIC BONDS


When an atom loses an electron it would have one more
positively charged proton (+) then electrons, therefore, the
atom would be carrying an overall net charge of (1+). When
an atom gains and electron it contains one more electron
than protons and therefore would be carrying a net charge
of (1-).
Atoms which have gained or lost electrons are called ions.
Ions are charged, atoms or molecules. Anions carry a
negative charge eg. (Cl-) while cations carry a positive
charge (Na+).

Where covalent bonds involve shared electrons, "ionic
bonds" are formed when one atom gives up an electron
from an outer shell (orbital) and the other atom adds the
free electron to its outer most orbital, thereby holding the
atoms together in an energetically stable unit.
63
IONIC BONDS
64
IONIC BONDS



Chlorine is in a group of elements having seven electrons in their
outer shells. Members of this group tend to gain one electron,
acquiring a charge of -1.
Sodium is in another group with elements having one electron in
their outer shells. Members of this group tend to lose that outer
electron, acquiring a charge of +1.
Oppositely charged ions are attracted to each other, thus Cl- (the
symbolic representation of the chloride ion) and Na+ (the symbol for
the sodium ion, using the Greek word natrium) form an ionic bond,
becoming the molecule sodium chloride,.

Ionic bonds generally form between elements in Group I (having one
electron in their outer shell) and Group VIIa (having seven electrons in
their outer shell). Such bonds are relatively weak, and tend to disassociate
in water, producing solutions that have both Na and Cl ions.

Ionic bonds are formed when atoms become ions by gaining or losing
electrons.
65
66
HYDROGEN BONDS

Individually these bonds are very weak, although taken in
a large enough quantity, the result is strong enough to hold
molecules together or in a three-dimensional shape.

Hydrogen bonds, result from the weak electrical attraction
between the positive end of one molecule and the negative
end of another.
67
68
Molecules are compounds in which the elements are in
definite, fixed ratios.

Those atoms are held together usually by one of the three
types of chemical bonds discussed above.


Mixtures are compounds with variable formulas/ratios of
their components.


For example: water, glucose, ATP.
For example: soil.

Molecular formulas are an expression in the simplest
whole-number terms of the composition of a substance.

For example, the sugar glucose has 6 Carbons, 12 hydrogens,
and 6 oxygens per repeating structural unit. The formula is
written C6H12O6.
69
70
CHEMISTRY II: WATER AND ORGANIC
MOLECULES
STRUCTURE OF WATER

Water is polar covalently bonded within the
molecule.
This unequal sharing of the electrons results in a
slightly positive and a slightly negative side of the
molecule.
 Other molecules, such as Ethane, are nonpolar,
having neither a positive nor a negative side

71
72
Water has been referred to as the universal
solvent.
 Living things are composed of atoms and
molecules within aqueous solutions (solutions
that have materials dissolved in water).


Solutions are uniform mixtures of the molecules
of two or more substances.
The solvent is usually the substance present in
the greatest amount (and is usually also a liquid).
The substances of lesser amounts are the solutes.

73
SOLUBILITY

The solubility of many molecules is
determined by their molecular
structure.


The polar covalently bonded water
molecules act to exclude nonpolar
molecules, causing the fats to clump
together.
The structure of many molecules
can greatly influence their
solubility. Sugars, such as glucose,
have many hydroxyl (OH) groups,
which tend to increase the solubility
of the molecule.

You are familiar with the phrase
"mixing like oil and water." The
biochemical basis for this phrase is
that the organic macromolecules
known as lipids (of which fats are an
important, although often
troublesome, group) have areas that
lack polar covalent bonds.
74
HYDROGEN POTENTIAL (PH)

In this disassociation, the oxygen
retains the electrons and only one of
the hydrogens, becoming a
negatively charged ion known as
hydroxide.

Pure water has the same number
(or concentration) of H+ as OH- ions.

Acidic solutions have more H+ ions
than OH- ions.

Basic solutions have the opposite.
An acid causes an increase in the
numbers of H+ ions and a base
causes an increase in the numbers
of OH- ions.

Water tends to disassociate into H+
and OH- ions.
75


Remember that as the H+
concentration increases the OHconcentration decreases and
vice versa .
If we have a solution with one
in every ten molecules being
H+, we refer to the
concentration of H+ ions as
1/10. Remember from algebra
that we can write a fraction as
a negative exponent, thus 1/10
becomes 10-1. Conversely 1/100
becomes 10-2 , 1/1000 becomes
10-3, etc.

Logarithms are exponents to
which a number (usually 10)
has been raised. For example
log 10 (pronounced "the log of
10") = 1 (since 10 may be
written as 101). The log 1/10 (or
10-1) = -1. pH, a measure of the
concentration of H+ ions, is the
negative log of the H+ ion
concentration. If the pH of
water is 7, then the
concentration of H+ ions is 10-7,
or 1/10,000,000. In the case of
strong acids, such as
hydrochloric acid (HCl), an acid
secreted by the lining of your
stomach, [H+] (the
concentration of H+ ions,
written in a chemical
shorthand) is 10-1; therefore the
pH is 1.

The pH scale is a logarithmic
scale representing the
concentration of H+ ions in a
solution.
76
77
ORGANIC MOLECULES
(BIOMOLECULES)
ORGANIC MOLECULES


If we remove the H from one of the
methane units below, and begin
linking them up, while removing
other H units, we begin to form an
organic molecule.

(NOTE: Not all methane is
organically derived, methane is a
major component of the atmosphere
of Jupiter, which we think is devoid
of life).

When two methanes are combined,
the resultant molecule is Ethane,
which has a chemical formula C2H6.
Molecules made up of H and C are
known as hydrocarbons.

Organic molecules are those that: 1)
formed by the actions of living
things; and/or 2) have a carbon
backbone.
Methane (CH4) is an example of
this.
78
FUNCTIONAL GROUPS


unctional groups are clusters of
atoms with characteristic structure
and functions. Polar molecules
(with +/- charges) are attracted to
water molecules and are
hydrophilic. Nonpolar molecules are
repelled by water and do not
dissolve in water; are hydrophobic.

Scientists eventually realized that
specific chemical properties were a
result of the presence of particular
functional groups. F
Hydrocarbon is hydrophobic except
when it has an attached ionized
functional group such as carboxyl
(acid) (COOH), then molecule is
hydrophilic.
79

Monomers can be joined together to form
polymers that are the large macromolecules
made of three to millions of monomer subunits.

Each organic molecule group has small molecules
(monomers) that are linked to form a larger
organic molecule (macromolecule).
80


Cellular enzymes carry out condensation (and the reversal
of the reaction, hydrolysis of polymers). Condensation
involves a dehydration synthesis because a water is
removed (dehydration) and a bond is made (synthesis).
When two monomers join, a hydroxyl (OH) group is
removed from one monomer and a hydrogen (H) is removed
from the other.

This produces the water given off during a condensation
reaction. Hydrolysis (hydration) reactions break down
polymers in reverse of condensation; a hydroxyl (OH) group
from water attaches to one monomer and hydrogen (H)
attaches to the other.

Macromolecules are constructed by covalently bonding
monomers by condensation reactions where water is
removed from functional groups on the monomers.
81
82
MAIN BIOMOLECULES
THE MOST IMPORTANT MACROMOLECULES
IN BIOLOGY…

There are four classes of macromolecules
(polysaccharides, triglycerides, polypeptides,
nucleic acids). These classes perform a variety of
functions in cells.
83
BIOMOLECULES SUMMARY…
LAS PRINCIPALES MOLÉCULAS BIOLÓGICAS
Principales subtipos
(subunidades en paréntesis)
Ejemplo
Función
Carbohidrato:
normalmente contiene
carbono, oxígeno e
hidrógeno y tiene la
formula aproximada
(CH2O)n
Monosacárido: azúcar simple
Disacárido: dos monosacáridos
enlazados
Polisacárido: muchos
monosacáridos (normalmente
glucosa) enlazados
Glucosa
Sacarosa
Almidón
Glucógeno
Celulosa
Importante fuente de energía para las
células; subunidad con la que se hacen casi
todos los polisacáridos
Principal azúcar transportado dentro del
cuerpo de las plantas terrestres
Almacén de energía en plantas
Almacén de energía en animales
Material estructural de plantas
Lípido:
Contiene una proporción
elevada de carbono e
hidrógeno; suele ser no
polar e insoluble en agua
Tliglicerido: tres ácidos grasos
unidos a glicerol
Cera: número variable de ácidos
grasos unidos a un alcohol de
cadena larga
Fosfolípido: grupo fosfato polar
y dos ácidos grasos unidos a
glicerol
Esteroide: 4 anillos fusionados
de átomos de carbono, con
grupos funcionales unidos
Aceite, grasa
Ceras en la cutícula
de las plantas
Fosfatidilcolina
Colesterol
Almacén de energía en animales y algunas
plantas
Cubierta impermeable de las hojas y tallos
de plantas terrestres
Componente común de las membranas de
las células
Componente común de las membranas de
las células eucarióticas; precursor de otros
esteroides como testosterona, sales biliares
Clase de molécula
84
BIOMOLECULES…
LAS PRINCIPALES MOLÉCULAS BIOLÓGICAS
Clase de molécula
Acido nucleico:
Formado por subunidades
llamadas nucleótidos;
puede ser uno solo o una
cadena larga de
nucleótidos.
Ejemplo
Función
Queratina
Seda
Hemoglobina
Ácidos nucleicos de cadena larga
Nucleótidos individuales
Acido
desoxirribonucleico
(ADN)
Acido Ribonucleico
(ARN)
Trifosfato de
adenosina (ATP)
Monofosfato de
adenosina cíclico
(AMP cíclico)
Proteína helicoidal, principal componente
del pelo
Proteína producida por polillas y arañas
Proteína globular formada por 4
subunidades peptídicas; transporta oxígeno
en la sangre de los vertebrados
Material genético de todas las células vivas
Material genético de algunos virus; en las
células vivas es indispensable para transferir
la información genética del ADN a las
proteínas
Principal molécula portadora de energía a
corto plazo en las células
Mensajero intracelular
Proteína:
Cadenas de aminoácidos;
contiene carbono,
hidrógeno, oxígeno,
nitrógeno y azufre
Principales subtipos
(subunidades en paréntesis)
(aminoácidos)
85
Sugars…
86
CARBOHYDRATES
CARBOHYDRATES

Carbohydrates function in
short-term energy storage
(such as sugar); as
intermediate-term energy
storage (starch for plants
and glycogen for animals);
and as structural
components in cells
(cellulose in the cell walls of
plants and many protists),
and chitin in the
exoskeleton of insects and
other arthropods.


Sugars are structurally the
simplest carbohydrates.
They are the structural unit
which makes up the other
types of carbohydrates.
Monosaccharides are
single (mono=one) sugars.
Important monosaccharides
include ribose (C5H10O5),
glucose (C6H12O6), and
fructose (same formula but
different structure than
glucose).

Carbohydrates have the
general formula [CH2O]n
where n is a number
between 3 and 6.
87
ALFA AND BETA GLUCOSE
88
DISACCHARIDES



Sucrose, a common plant disaccharide is composed of the
monosaccharides glucose and fructose.
Lactose, milk sugar, is a disaccharide composed of glucose
and the monosaccharide galactose.

are formed when two monosaccharides are chemically
bonded together.
The maltose that flavors a malted milkshake (and other
items) is also a disaccharide made of two glose molecules
bonded together
89
90
DISACCHARIDES: "DEHYDRATION SYNTHESIS".
When two monosaccharides are
joined together they form a
"disaccharide".
This linking of two sugars involves
the removal of a molecule of H2O
(water) and is therefore called a
"dehydration linkage". The
reaction is called "dehydration
synthesis".
e.g. Glucose + Glucose = Maltose
91

Polysaccharides

These are long chains
of monosaccharides
linked together by
dehydration linkages.
92
POLYSACCHARIDES


Two forms of polysaccharide, amylose and
amylopectin makeup what we commonly call starch.
The formation of the ester bond by condensation (the
removal of water from a molecule) allows the linking
of monosaccharides into disaccharides and
polysaccharides. Glycogen (see Figure 12) is an
animal storage product that accumulates in the
vertebrate liver.

are large molecules composed of individual
monosaccharide units. A common plant
polysaccharide is starch which is made up of many
glucoses (in a polypeptide these are referred to as
glucans).
93
CELLULOSE (HOMOPOLYSACARID)

is a polysaccharide found
in plant cell walls.


As compared to starch and
glycogen, which are each
made up of mixtures of a
and b glucoses, cellulose
(and the animal structural
polysaccharide chitin) are
made up of only b glucoses.

Cellulose forms the
fibrous part of the plant
cell wall.
In terms of human diets,
cellulose is indigestible,
and thus forms an
important, easily obtained
part of dietary fiber.
94
HETEROPOLYSACARIDS

Chitin: is an important structural material in the outer coverings
of insects, crabs, and lobsters. In chitin the basic subunit is not
glucose (but N-acetyl-D-glucoseamine) in 1-4 linkages. These
polymers are made very hard when impregnated with calcium
carbonate.
95
Fatty acids
96
LIPIDS
LIPIDS



They are generally insoluble in
polar substances such as water.
Secondary functions of lipids
include structural components (as
in the case of phospholipids that are
the major building block in cell
membranes) and "messengers"
(hormones) that play roles in
communications within and
between cells.
Lipids are composed of three fatty
acids (usually) covalently bonded to
a 3-carbon glycerol. The fatty acids
are composed of CH2 units, and are
hydrophobic/not water soluble.


Fatty acids can be saturated
(meaning they have as many
hydrogens bonded to their carbons
as possible) or unsaturated (with
one or more double bonds
connecting their carbons, hence
fewer hydrogens).
A fat is solid at room temperature,
while an oil is a liquid under the
same conditions.



The fatty acids in oils are mostly
unsaturated,
while those in fats are mostly
saturated.

are involved mainly with long-term
energy storage.
Lipids include the compounds
commonly known as fats, oils, and
waxes. We will look at three
important classes of lipids.
97
THE TRIGLYCERIDES



Both fats and oils are
"triglycerides". These
molecules are made up of 3
long chain "fatty acids"
attached to a 3 carbon
molecule called "glycerol".
The carboxyl and the fatty
acids are attached to the OH groups of the Glycerol
via a "dehydration
synthesis" reaction to yield
an "ester" bond.
Function: storage of
energy - "fat" in animals,
and "oils" in plants.
98


Fats and oils function in long-term
energy storage.
Most plants store excess
sugars as starch, although
some seeds and fruits have
energy stored as oils (e.g.
corn oil, peanut oil, palm oil,
canola oil, and sunflower
oil).
Fats yield 9.3 Kcal/gm,
while carbohydrates yield
3.79 Kcal/gm. Fats thus
store six times as much
energy as glycogen.

Animals convert excess
sugars (beyond their
glycogen storage capacities)
into fats.
99
SATURATED AND UNSATURATED FATTY
ACIDS
Saturated Fatty Acid: These are fatty acids
which contain the maximum possible number of
hydrogen atoms. That is each carbon in the chain
has two hydrogen atoms attached to it. It is
"saturated" with hydrogen atoms.
Unsaturated Fatty Acid: These are fatty acids which
contain carbon-to-carbon "double" bonds. Therefore since a
carbon atom can have only 4 covalent bonds, there is one
less bond available for hydrogen, therefore there is one less
hydrogen. (The carbons are not "saturated" with hydrogen
atoms.)
100
the next questions:
1. What
Directions.
1.
Work in teams
of three
2.
Read the next 6
slides
3.
To generate a
mindmap over
all the 6 slides
in a papersheet
4.
Generate a
table showing
differences
between cis
and trans
Tellez Carmona José Maneeuel
are satured and unsatured
fatty acids?
2. Are both of them good or bad for
your healthy?
3. What is an eicosanoid?
4. What is hydrogenation? What is
used for?
5. What are Cis and trans
configuration?
6. Which is best for your health of both
of them?
7. What is the meaning of LDL and
HDL and what is used for each one
of them?
8. Why is trans bad for your brain and
heart?
CLASS ACTIVITY
1. Answer
101
FATTY ACID CONFIGURATIONS
TRANS FATS: WHAT'S UP WITH THAT?
What are Trans Fats?
Double bonds bind
carbon atoms tightly
and prevent rotation
of the carbon atoms
along the bond axis.
This gives rise
to configurational
isomers which are
arrangements of
atoms that can only
be changed by
breaking the bonds.


Cis configuration (oleic Acid)
Trans configuration (Elaidic
acid)
Cis means "on the same side" and Trans means "across"
or "on the other side"

Configurational isomers
102
WHAT IS HYDROGENATION AND PARTIAL
HYDROGENATION?


Unsaturated fats exposed to air
oxidize to create compounds that
have rancid, stale, or unpleasant
odors or flavors.
Hydrogenation is a commercial
chemical process to add more
hydrogen to natural unsaturated fats
to decrease the number of double
bonds and retard or eliminate the
potential for rancidity.
Unsaturated oils, such as soybean
oil, which contain unsaturated fatty
acids like oleic and linoleic acid, are
heated with metal catalysts in the
presence of pressurized hydrogen
gas.



Hydrogen is incorporated into
the fatty acid molecules and
they become saturated with
hydrogen. Oleic acid (C18:1) and
linoleic acid (C18:2) are both
converted to stearic acid (C18:0)
when fully saturated.
The liquid vegetable oil
becomes a solid saturated fat
(shortening with a large
percentage of tristearin).
By comparison, animal fats
seldom have more than 70%
saturated fatty acid radicals. In
the table above, for example,
lard has 54% unsaturated fatty
acid radicals.

103
METABOLISM OF FATS -- WHY ARE TRANS
FATS BAD?
Metabolism of natural C20 Cis fatty
acids produces powerful
eicosanoids.


Metabolism of natural 20-carbon
polyunsaturated fatty acids like
arachidonic acid results in the
biosynthesis of mediators with
potent physiological effects such as
prostaglandins, prostacyclins,
thromboxanes, leucotrienes, and
lipoxins.
These substances are known
collectively as eicosanoids because
they contain 20 carbon atoms (Greek
eikosi = 20).
However, polyunsaturated trans
fatty acids cannot be used to
produce useful mediators because
the molecules have unnatural shapes
that are not recognized by enzymes
such as cyclooxygenase and
lipoxygenase.
Although low levels of trans-vaccenic acid
occur naturally in some animal food
products, partially hydrogenated oils contain
a large proportion of diverse trans fatty
acids.
When large amounts of Trans fatty acids are
incorporated into the cells, the cell
membranes and other cellular structures
become malformed and do not function
properly.

104
TRANS IS BAD FOR YOUR HEART…




Both of these conditions are associated with insulin
resistance which is linked to diabetes, hypertension, and
cardiovascular disease.
Harvard University researchers have reported that people
who ate partially hydrogenated oils, which are high in Trans
fats, had nearly twice the risk of heart attacks compared with
those who did not consume hydrogenated oils. B
ecause of the overwhelming scientific evidence linking Trans
fats to cardiovascular diseases, the Food and Drug
Administration will require all food labels to disclose the
amount of Trans fat per serving, starting in 2006.

Trans fats are bad for your heart.
Dietary trans fats raise the level of low-density lipoproteins
(LDL or "bad cholesterol") increasing the risk of coronary
heart disease. Trans fats also reduce high-density lipoproteins
(HDL or "good cholesterol"), and raise levels of triglycerides in
the blood.
105
TRANS IS BAD FOR YOUR BRAIN…



Studies show that trans fatty acids in the diet get incorporated into brain cell
membranes, including the myelin sheath that insulates neurons. These synthetic
fats replace the natural DHA in the membrane, which affects the electrical
activity of the neuron.

Trans fatty acid molecules alter the ability of neurons to communicate and may
cause neural degeneration and diminished mental performance.

Neurodegenerative disorders such as multiple sclerosis (MS), Parkinson's
Disease, and Alzheimer's Disease appear to exhibit membrane loss of fatty acids.

Unfortunately, our ingestion of trans fatty acids starts in infancy. A Canadian
study showed that an average of 7.2% of the total fatty acids of human breast
milk consisted of trans fatty acids which originated from the consumption of
partially hydrogenated vegetable oils by the mothers.

Trans fats are bad for your brain.
Trans fats also have a detrimental effect on the brain and nervous system. Neural
tissue consists mainly of lipids and fats.
Myelin, the protective sheath that covers communicating neurons, is composed of
30% protein and 70% fat. Oleic acid and DHA are two of the principal fatty acids
in myelin.
106
WHAT ARE OMEGA-3 AND OMEGA-6 FATTY
ACIDS?
HOMEWORK: INDIVIDUAL! SEARCH ABOUT
BOTH OMEGA ACIDS, IN AT LEAST TWO
DIFFERENT WEBSITES (OBVIOUSLY
WiTHOUT LOOKING FOR IN rincondelvago,
wikipedia, monografias, etc. You may look for in
the next website http://www.clo3.com/home.php
 Search for function
 Key benefits of omega 3
 Why are they so necessary for human diet
 Tridimensional shape
 DELIVERY FORM: VIA EMAIL TO
manueltllz@gmail.com

107
PHOSPHOLIPIDS


The negatively charged phosphate
group (and its various end groups)
cause this end of the molecule to
form a "polar" covalent bond with
glycerol. That is this end of the
phospholipid molecule is "polar"
while the fatty acid chain is "nonpolar".

These molecules are structurally
similar to the triglycerides, but they
differ in one important respect.
Triglycerides have 3 fatty acid
chains, but the phospholipids have
only 2 fatty acid chains and one
phosphate (-) group.
Since water is also a polar molecule the polar end of
the phospholipid is "attracted" to the + ends of the
water molecules. It is said to be "hydrophillic" (or
water loving). While the neutral end of the
phospholipid molecule is non-polar, i.e. is repelled by
the "polar" water molecules, it is said to be
"hydrophobic" (water fearing).
Therefore one end of the molecule is
charged (-), i.e. polar and the other
end of the molecule is not charged
(neutral), i.e. non-polar.
108
THIS DUEL NATURE OF THE PHOSPHOLIPID
MOLECULE MAKES IT VERY USEFUL AS A
COMPONENT OF CELL MEMBRANES.
109
PROTEINS
110
AMINOACIDS, PEPTIDES AND
PROTEINS
Proteins are often called "polypeptides" because they are made of
long chains of building blocks called "amino acids"
Function
Structure
Motion
Defense
Almacenamiento
Signals
Catalysis
Main protein functions
Example
Colagen in skin, keratine in hair, nails and horns
Actine and miosine in muscles
Antibodies in blood stream
Zeatine in cornpops
Growth hormone in blood stream
Enzimes: they catalize almost every chemical
reaction within cells, DNA polimerase (produces
DNA); pepsine (digers proteins); amilase (digers
carbohydrates); ATP synthetase (produces ATP)
These are very large 3 dimensional macromolecules. They are very
important as structural molecules in the cell, as energy sources,
and most importantly as "enzymes", (protein catalysts which
speed up chemical reactions in the cell without the need for high
temperature or drastic pH changes).
111
STRUCTURE OF SOME AMINO ACIDS
- R groups can be any of 20 different forms giving 20 naturally
occurring amino acids (in living things)
112
STRUCTURE OF PROTEINS



Primary
Structure (or
primary level of
organization)
Definition. "The
sequence of
amino acids in
the
polypeptide
chain.“
Amino acids are
bound together
with a "peptide"
bond.
113
SECONDARY LEVEL OF ORGANIZATION
OF POLYPEPTIDES




There are two types of
secondary structure in proteins,
the α helix and the β pleated
sheet.
The attraction of the R groups
within the same chain can
cause the chain to twist into a
"right handed" coil.
This " α helix" is held together
by hydrogen bonds between the
hydrogen and oxygen atoms of
the amino acid backbone
(amino groups and carboxyl
groups).
Such "Intrachain Hydrogen
Bonding" often predominate in
"globular proteins".
Keratin is a structural protein found in hair and nails, skin, and
tortoise shells. The aHelix nature of wool is what makes it shrink.
114

The β pleated sheet
structure is often found in
many structural proteins,
such as "Fibroin", the
protein in spider webs.

Another form of secondary
structure the β pleated
sheet, is caused by
hydrogen bonding between
the hydrogen atoms
(amino group) and the
oxygen atoms (carboxyl
group) of amino acids on
two chains (or more) lying
side-by-side.
115
THE TERTIARY STRUCTURE OF
PROTEINS


This 3 dimensional shape is
also held together by weak
hydrogen bonds but also by
much stronger "disulfide" bonds
between two amino acids of
cystine ("covalent") disulfide
"bridges" (linkages)
cystine -- s -- s -- cystine

When "proline", an oddly
shaped amino acid occurs in the
polypeptide chain a "kink" in
the ahelix develops. Kinks can
also be caused by repulsive
forces between adjacent
charged R groups. These kinks
create a 3 dimensional chain
arrangement, ie. the "Tertiary"
Structure
116
QUATERNARY STRUCTURE OF PROTEINS

Many enzymes and
transport proteins are
made of two or more
parts.

This last level of
organization is simply
taking 2 or more 3
dimensional (tertiary
proteins) and sticking
them together to form
a larger protein.
117
STRUCTURE OF PROTEINS
118
DENATURE
Proteins when heated can unfold or "Denature".
This loss of three dimensional shape will usually be accompanied
by a loss of the proteins function.
If the denatured protein is allowed to cool it will usually refold
back into it’s original conformation.
119
NUCLEIC ACIDS



They are also long chain
macromolecules. The repeating
subunits (building blocks) of
these molecules are called
"nucleotides".
Nucleotides have three parts,
a sugar (usually the six
carbon sugar ribose or
deoxyribose), a phosphate
group (P04) and a base (which
contains nitrogen).

These macromolecules include
the Ribonucleic Acids
(RNA's) and the
Deoxyribonucleic Acids
(DNA's).
120
BASIC STRUCTURE


The two strands of DNA are
said to form the "DNA
molecule".
Note: that one strand runs
in one "direction" and the
other strand runs in the
opposite "direction".

Nucleic acids form long
chains by linking the
phosphate groups to the
sugars. The nitrogen bases
stick out to the side. When
DNA is formed there are
two chains of nucleotides,
each of which tends to coil
around the other forming
the so called "double helix".
121
The DNA double helix.
Some differences between each
nucleic acid


Deoxyribonucleic acid (DNA) is
composed of deoxyribose sugar and
four nitrogen bases,
Complementary base paired, as
follows;
Adenine = = = Thymine
Guanine = = = Cytosine





RNA differs from DNA in that
there is only one strand, and RNA
uses ribose as its sugar, and RNA
substitutes Uracil for Thymine.
Adenine - Uracil
Guanine - Cytosine

122
123

biology - Manuel Tellez

Transcription

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