ZOL 14 1st Edition Lecture 2 Outline of Last Lecture II The Beginning of Human Genetics III Age of DNA IV Human Genome Project V Social and Ethical Effects of Genetics Eugenics Movement Outline of Current Lecture VI Genes and Genomes VII Macromolecules VIII DNA RNA IX Nucleic Acids Made of nucleotides X Polynucleotides Current Lecture Genes and Genomes What is a trait o An observable property of an organism What is a gene o The fundamental unit of heredity o Basic structural and functional unit of genetics What is DNA o Deoxyribonucleic acid o Helical molecule consisting of two strands of nucleotides o Carrier of genetic info What is a Genome o Set of DNA sequences carried by an individual o Biggest genome 132 8 billion bp Macromolecules Large cellular polymers assembled by chemically linking monomers together o o Carbohydrates Subclasses Monosaccharides Oligosaccharides Polysaccharides Examples Glucose sucrose starch glycogen Function Energy source common sugar energy storage Lipids Subclasses Glycerides Phospholipids Sterols Examples Fats Lecithin Cholesterol Function energy storage structure of cell membranes membrane structure precursor to steroid hormones o o 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 system Nucleic acids Subclasses adenosine phosphates Nucleic acids Examples ATP DNA RNA Functions Energy carrier storage transmission of genetic info DNA RNA o RNA mRNA messenger RNA tRNA transfer RNA rRNA ribosomal RNA o DNA Found in ALL living organism Carrier of genetic info 3 Key Properties of DNA 1 Needs to store genetic info stored in sequence A C G T nucleotides Almost infinite combinations 2 Needs to be self replicating Structure must allow faithful replication 3 Needs to be able to mutate Mutations caused by changing bases Nucleic Acids Made of nucleotides Polynucleotides Nucleotide building block of DNA Phosphate sugar o Sugars pentose deoxyribose missing oxygen in DNA ribose RNA o Bases DNA Adenine Thymine Guanine Cytosine RNA Adenine Uracil Guanine Cytosine o How do they differ IMPORTANT A and G are purines two rings C T U Pyrimidines 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 directions o Sugar and phosphate on outside o Bases on inside Base pairing specific o A T 2 hydrogen bonds o C G 3 hydrogen bonds o Chargaff Rules Purines must pyrimidines A T G C