Lecture 5 Introduction to Kingdom Monera
Transcription
Lecture 5 Introduction to Kingdom Monera
Passive Transport: a primer Diffusion Concentration gradient Substance specific!!!!!!!!! Passive transport Osmosis LE 7-11a Molecules of dye Membrane (cross section) WATER Net diffusion Net diffusion Equilibrium Net diffusion Equilibrium Diffusion of one solute Net diffusion Net diffusion Net diffusion Equilibrium LE 7-12 Lower concentration of solute (sugar) Higher concentration of sugar H2O Selectively permeable membrane: sugar molecules cannot pass through pores, but water molecules can Osmosis Same concentration of sugar Lecture 5 Introduction to Domain Bacteria and Archaea (aka Kingdom Monera) The First Forms of Life 3.5-4.0 bya Simple ≠ primitive 4 Billion years of evolution!!! Prokaryotes are the Simplest Form of Life Small (1-5 μm) Uncomplicated structure Evolution and diversity chemical level Single cells colonies Prokaryotic Structural Diversity Limited to three shapes Spherical -> cocci Rod-shaped -> bacilli Helical -> spirochetes or spirilla Prokaryotes v. Eukaryotes See Table 27.2 All cells have: - Plasma membrane - Chromosomes - Cytosol - ribosomes Nuceoid No organelles Small High SA/V Nucleus Organelles Big Low SA/V Basic Prokaryotic Cell Structure Cytoplasm cell membrane cell wall DNA Basic Prokaryotic Cell Structure cell membrane cell wall Classification of the Prokaryotes Two main branches: Archaea, Bacteria Five kingdom system (both in Kingdom Monera) Three domain system (separate domains) Distinction between Archaea and Bacteria Archaea (archaebacteria) older confined to extreme habitats Distinction between Archaea and Bacteria Archaea have no peptidoglycan in cell wall Distinction between Archaea and Bacteria Bacteria (eubacteria) Bulk of the prokaryotes Peptidoglycan in cell wall Different types of molecules Two basic types of nutrition Heterotrophs Autotrophs Two basic types of nutrition Heterotrophs Absorb organic molecules directly from their environment Glucose Two basic types of nutrition Heterotrophs use organic molecules as sources of energy and building blocks Glucose Two basic types of nutrition Autotrophs Produce their own organic molecules by photosynthesis Two basic types of nutrition Autotrophs use outside energy source such as light from the sun CO2 as their carbon source CO2 E. coli: a Heterotrophic Bacterium inhabitant of the intestines of mammals including humans used in testing for water quality (coliform count) only glucose as an energy source E. coli: a Heterotrophic Bacterium can construct all other organic molecules from glucose a bacillus Nostoc: an Autotrophic Bacterium Filamentous bacterium String of green beads Most contain chlorophyll Photosynthesis releases oxygen Nostoc: an Autotrophic Bacterium Heterocysts are larger and clear Heterocysts do not photosynthesize Heterocysts fix nitrogen