1. GENETICS ESSENTIALS Concepts and Connections SECOND EDITION GENETICS ESSENTIALS Concepts and Connections SECOND EDITION Benjamin A. Pierce © 2013 W. H. Freeman and Company CHAPTER 11 From DNA to Proteins: Translation

2. CHAPTER 11 OUTLINE 11.1 The Genetic Code Determines How the Nucleotide Sequence Specifies the Amino Acid Sequence of a Protein, 288 11.2 Amino Acids Are Assembled into a Protein Through the Mechanism of Translation, 293 11.3 Additional Properties of Translation and Proteins, 299

4. 11.1 THE GENETIC CODE DETERMINES HOW THE NUCLEOTIDE SEQUENCE SPECIFIES THE AMINO ACID SEQUENCE OF A PROTEIN The One Gene, One Enzyme Hypothesis Genes function by encoding enzymes, and each gene encodes a separate enzyme. More specific: one gene, one polypeptide hypothesis

5. 11.1 THE GENETIC CODE DETERMINES HOW THE NUCLEOTIDE SEQUENCE SPECIFIES THE AMINO ACID SEQUENCE OF A PROTEIN The Structure and Function of Proteins Proteins are polymers consisting of amino acids linked by peptide bonds. Amino acid sequence is its primary structure. This structure folds to create secondary and tertiary structures. Two or more polypeptide chains associate to form quaternary structure.

8. 11.2 The Genetic Code Determines How the Nucleotide Sequence Specifies the Amino Acid Sequence of a Protein Characteristics of the Genetic Code The degeneracy of the code The reading frame and initiation codons Termination codons The universality of the code

9. Breaking the Genetic Code Homopolymers Random copolymers Ribosome-bound tRNAs Codon: a triplet RNA code

10. Degenerate code: Amino acid may be specified by more than one codon. Synonymous codons: codons that specify the same amino acid. Isoaccepting tRNAs: different tRNAs that accept the same amino acid but have different anticodons. The Degeneracy of the Code

11. Codons Sense codons: encoding amino acid Initiation codon: AUG Termination codon: UAA, UAG, UGA Wobble hypothesis The Degeneracy of the Code

12. Wobble hypothesis The Degeneracy of the Code

13. Reading frame: three ways in which the sequence can be read in groups of three. Each different way of reading encodes a different amino acid sequence. Non-overlapping: A single nucleotide may not be included in more than one codon. The universality of the code: near universal, with some exceptions. The Reading Frame and Initiation Codons

14. 11.2 Amino Acid Are Assembled into a Protein Through the Mechanism of Translation The Binding of Amino Acids to Transfer RNAs The Initiation of Translation Elongation Termination

16. Aminoacyl-tRNA syntheses and tRNA charging The specificity between an amino acid and its tRNA is determined by each individual aminoacyl-tRNA synthesis. There are exactly 20 different aminoacyl-tRNA syntheses in a cell. The Binding of Amino Acids to Transfer RNAs

17. Initiation factors IF-3, initiator tRNA with N- formylmethionine attached to form fmet-tRNA Energy molecule: GTP The Initiation of Translation

18. The Shine-Dalgarno consensus sequence in bacterial cells is recognized by the small unit of ribosome. The Kozak sequence in eukaryotic cells facilitates the identification of the start codon. The Initiation of Translation

21. The Kozak sequence in eukaryotic cells facilitates the identification of the start codon. The Initiation of Translation

23. Aminoacyl site A Peptidyl site P Exit site E Elongation factors: Tu, Ts, and G Elongation

27. Termination codons: UAA, UAG, and UGA Release factors Termination

31. The three-dimensional structure of the ribosome Polyribosomes: An mRNA with several ribosomes attached 11.3 Additional Properties of Translation and Proteins

33. Post-translational Modifications of Proteins Chaperons Translation and Antibiotics 11.3 Additional Properties of Translation and Proteins