1. Introduction to Genetics A.Definition of “Genetics” B.Proteins C.Nucleic Acids D.The Central Dogma of Genetics E.Historical Perspective

2. A.Definition of “Genetics” Genetics: Understanding how information for protein structure is transmitted, structured, and expressed – Transmission of genetic information during reproductive processes: Heredity – Structure of genetic information – Expression of genetic information

3. General properties –Composed of chains of amino acids –There are 20 different amino acids, each with distinctive chemical properties –A protein molecule may contain several hundred amino acids –Each different protein has its own order, or “sequence,” of amino acids –The correct sequence of amino acids is essential for the protein’s function B.Proteins

4. Functions –Enzymes: enzymes are biological catalysts that control almost every reaction in living systems –Cellular recognition and communication –Structural components of living cells B.Proteins

5. Levels of protein structure –Primary structure: amino acid sequence –Secondary structure: localized folding of a chain into regions of helix or sheet structure –Tertiary structure: folding of a single polypeptide chain into a three-dimensional structure –Quaternary structure: only in proteins with more than one polypeptide chain; Folding of more than one chain together B.Proteins

6. General properties –Composed of chains of nucleotides –There are 4 different nucleotides –A nucleic acid molecule may contain several thousands or millions of nucleotides –Each nucleic acid molecule has its own order, or “sequence,” of nucleotides –The correct sequence of nucleotides is essential for the nucleic acid’s function C.Nucleic Acids

7. Overall function. The sequence of nucleotides in a nucleic acid molecule serves as a blueprint to encode the correct sequence of amino acids for a protein. The code for a specific protein is called a “gene.” Deoxyribonucleic acid (DNA): DNA molecules (chromosomes) serve as the “master blueprint” for all of the cell’s proteins. The DNA molecules are transmitted to offspring during reproduction. Ribonucleic acid (RNA): RNA molecules serve as “working copies” of the genes for the proteins that the cell is making at any given time. C.Nucleic Acids

8. D.Central Dogma of Genetics DNA replication Transcription Translation

9. E.Historical Perspective Early ideas –Preformation vs. Epigenesis –Dispersive Information vs. Germ Plasm Mid-1800s – Early 1900s: –Discovery and re-discovery of transmission genetics Early 1900s – Mid 1900s: –Discovery of the structure of the genetic information Mid 1900s – Early 2000s: –Mechanisms of genetic expression and regulation –Development of molecular genetics technology