Rekayasa Genetika
Transcription
Rekayasa Genetika
Rekayasa Genetika Genetics Engineering Genetics Engineering • what gene is made of ? • how it works ? • how it is transmitted from generation to generation ? Initially thought of in functional terms : It is a hereditary unit responsible for the appearance of particular biological characteristics, such as eye or hair color in human beings. Genetics Engineering • what gene is made of ? • how it works ? • how it is transmitted from generation to generation ? Gene is DNA or RNA BACKBONE • The backbones of both DNA and RNA are hydrophilic. • The hydroxyl groups of the sugar residues form hydrogen bonds with water. • The phosphate groups, with a pKa near 0, are completely ionized and negatively charged at pH 7, and the negative charges are generally neutralized by ionic interactions with positive charges on proteins, metal ions, and polyamines. NITROGEN BASE • Free pyrimidines and purines are weakly basic compounds and called bases. • They have a property with important consequences for the structure, electron distribution, and light absorption of nucleic acids. • All nucleotide bases absorb UV light, and nucleic acids are characterized by a strong absorption at wavelengths near 260 nm NITROGEN BASE • The purine and pyrimidine bases are hydrophobic and relatively insoluble in water at the near-neutral pH of the cell. • At acidic or alkaline pH the bases become charged and their solubility in water increases. Cell Organization Prokaryotes Eukaryotes • Cells are of 2 basic type: eukaryotic and prokaryotic • Each cell has about 2 m of DNA. • The average human has 75 trillion cells. • The average human has enough DNA to go from the earth to the sun more than 400 times. The earth is 150 billion m or 93 million miles from the sun. Genetics Engineering • what gene is made of ? • how it works ? • how it is transmitted from generation to generation ? DNA Transcription mRNA Translation Ribosome Polypeptide (protein) Washington State University adhingra@wsu.edu Inside a Living Cell Life alphabet 4 letters A, T, G, C English alphabet 26 letters Structure Static Function Dynamic Function Dynamic Genetics Engineering • what gene is made of ? • how it works ? • how it is transmitted from generation to generation ? • Genes are on chromosomes. – Bacterial cell : 1 chromosomes – Human : 46 chromosomes – Pigeon : 80 chromosomes • One chromosomes carries a large number of genes • Chromosomes are in a pair homologous chromosomes • Human : – 46 chromosomes = 23 pairs chromosome – 35.000 genes • Homologous chromosomes separate through mitosis and meiosis HUMAN CHROMOSOMES HUMAN CHROMOSOMES Washington State University adhingra@wsu.edu Terminology • The genome is an organism’s complete set of DNA. – a bacteria contains about 600,000 DNA base pairs – human and mouse genomes have some 3 billion. • human genome has 24 distinct chromosomes. – Each chromosome contains many genes. • Proteins – Make up the cellular structure – large, complex molecules made up of smaller subunits called amino acids. • Genotype: The genetic makeup of an organism • Phenotype: the physical expressed traits of an organism Washington State University adhingra@wsu.edu Terminology • Nucleic acid: Biological molecules(RNA and DNA) that allow organisms to reproduce • Gene: a discrete units of hereditary information located on the chromosomes and consisting of DNA. • Gene – basic physical and functional units of heredity. – specific sequences of DNA bases that encode instructions on how to make proteins. • Genome: an organism’s genetic material Genetics Engineering • Any artificial created DNA molecule which brings together DNA sequences that are not usually found together in nature. • Refers to any of a variety of sophisticated techniques for the creation of recombinant DNA and, in many cases, its subsequent introduction into living cells. Thank you