1. Protein Synthesis

2. Proteins Most diverse macromolecule Shape = function Responsible for many different functions – Structure – Signal – Enzyme – Defense – Motility

3. Archibald Garrod Studied alkaptonuria Inherited trait Mutation in enzyme Concluded gene responsible for enzyme

4. George Beadle and Edward Tatum Studied neurospora X-ray caused random mutations in genes Neurospora did not grow – Additional nutrients required Concluded one gene-one enzyme hypothesis – Later expanded one gene-one polypeptide hypothesis

5. Central Dogma

6. Transcription DNA → RNA Occurs in nucleus Why is this step needed? Why not DNA to protein directly?

7. DNA vs. RNA DNARNA (mRNA, tRNA, rRNA) Double strandSingle strand ThymineUracil Deoxyribose sugarRibose sugar Within nucleusWithin cell

8. RNA Messenger RNA (mRNA) – RNA version of DNA – Varies in length – Translated into protein Transfer RNA (tRNA) – Delivery system of amino acids – 70-90 base pairs Ribosomal RNA (rRNA) – Structural component of ribosome – Binds with proteins to form ribosomes – Varies in length

9. Translation RNA → polypeptide Occurs in cytosol Involves mRNA, tRNA, and rRNA

10. Genetic Code 4 bases, 20 amino acids…how? Codon: group of three base pairs – How many codons? – Each codon represents an amino acid or start/stop

11. Homework Page 318 # 3, 4, 7, 8, 11