ZOL 14 1st Edition Lecture 2Outline of Last Lecture II. The Beginning of Human GeneticsIII. Age of DNAIV. Human Genome ProjectV. Social and Ethical Effects of Genetics: Eugenics MovementOutline of Current Lecture VI. Genes and GenomesVII. MacromoleculesVIII.DNA/RNAIX. Nucleic Acids: Made of nucleotidesX. PolynucleotidesCurrent LectureGenes and Genomes- What is a trait?o An observable property of an organism- What is a gene?o The fundamental unit of heredityo Basic structural and functional unit of genetics- What is DNA?o Deoxyribonucleic acido Helical molecule consisting of two strands of nucleotideso Carrier of genetic info- What is a Genome?o Set of DNA sequences carried by an individualo Biggest genome= 132.8 billion bpMacromolecules: Large cellular polymers assembled by chemically linking monomers togethero Carbohydrates Subclasses: Monosaccharides, Oligosaccharides, Polysaccharides Examples: Glucose, sucrose, starch/glycogen Function: Energy source, common sugar, energy storageo Lipids Subclasses: Glycerides, Phospholipids, Sterols Examples: Fats, Lecithin, Cholesterol Function: energy storage, structure of cell membranes, membrane structure, precursor to steroid hormoneso Proteins Subclasses: mostly fibrous, mostly globular Examples: Keratin/Collagen, enzymes/hemoglobin/insulin/antibodies Functions: Structure of hair/structure of bones, catalysts/oxygen transport/hormone/immune systemo Nucleic acids Subclasses: adenosine phosphates, Nucleic acids Examples: ATP, DNA/RNA Functions: Energy carrier, storage/transmission of genetic infoDNA/RNAo RNA: mRNA: messenger RNA tRNA: transfer RNA rRNA: ribosomal RNAo DNA: Found in ALL living organism Carrier of genetic info- 3 Key Properties of DNA1. Needs to store genetic info- stored in sequence- A,C,G,T= nucleotides - Almost infinite combinations2. Needs to be self-replicating - Structure must allow faithful replication 3. Needs to be able to mutate- Mutations caused by changing basesNucleic Acids: Made of nucleotides- Nucleotide: building block of DNA- Phosphate & sugaro Sugars= pentose, deoxyribose (missing oxygen) (in DNA) & ribose (RNA)o Bases DNA: Adenine, Thymine, Guanine, Cytosine RNA: Adenine, Uracil, Guanine, Cytosineo How do they differ? IMPORTANT A and G are purines (two rings) C, T, U= PyrimidinesPolynucleotides Linking nucleotides together to form chains Have polarity (Phosphate at one end [5’]) (OH group at other end [3’])Covalent Chemical bond in which electrons are shared Within a molecule Can only be formed or broken chemically (enzymatically)Hydrogen bonds Weak bond between hydrogen and electronegative atom (oxygen) Between molecules or within large molecules Easily formed or broken by changing temp.DNA double helix Strands run in opposite directionso Sugar and phosphate on outsideo Bases on inside Base pairing specifico A & T: 2 hydrogen bondso C & G: 3 hydrogen bondso Chargaff Rules Purines must = pyrimidines A=T,
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