1. Fig. 17-5 Second mRNA base First mRNA base (5 end of codon) Third mRNA base (3 end of codon)

2. Polypeptide Ribosome Amino acids tRNA with amino acid attached tRNA Anticodon Trp Phe Gly Codons 3 5 mRNA the mechanism of translation

3. Fig. 17-14 Amino acid attachment site 3 5 Hydrogen bonds Anticodon (a) Two-dimensional structure Amino acid attachment site 5 3 Hydrogen bonds 3 5 Anticodon (c) Symbol used in this book (b) Three-dimensional structure

4. Amino acid Aminoacyl-tRNA synthetase (enzyme) ATP Adenosine PPP P P P i P P i i tRNA Aminoacyl-tRNA synthetase Computer model AMP Adenosine P Aminoacyl-tRNA (“charged tRNA”) Attaching amino acids to tRNAs: Amino-acyl tRNA synthases -20 different synthases -Require ATP -Each must be specific to the right amino acid and tRNA(s)

5. tRNA GLN Aminoacyl-tRNA synthase (ATS GLN ) Adenylated Glutamine

6. Fig. 17-16b P site (Peptidyl-tRNA binding site) A site (Aminoacyl- tRNA binding site) E site (Exit site) mRNA binding site Large subunit Small subunit (b) Schematic model showing binding sites Next amino acid to be added to polypeptide chain Amino end Growing polypeptide mRNA tRNA EP A E Codons (c) Schematic model with mRNA and tRNA 5 3

7. The Ribosome LSU SSU

8. Fig. 17-18-1 Amino end of polypeptide mRNA 5 3 E P site A site

9. Fig. 17-18-2 Amino end of polypeptide mRNA 5 3 E P site A site GTP GDP E P A

10. Fig. 17-18-3 Amino end of polypeptide mRNA 5 3 E P site A site GTP GDP E P A E PA

11. Peptide bond formation - Transfer of growing chain from tRNA in P site to tRNA in A site

12. Fig. 17-18-3 Amino end of polypeptide mRNA 5 3 E P site A site GTP GDP E P A E PA

13. Fig. 17-18-4 Amino end of polypeptide mRNA 5 3 E P site A site GTP GDP E P A E PA GTP Ribosome ready for next aminoacyl tRNA E P A

14. Fig. 17-17 3 3 5 5 U U A A C G Met GTP GDP Initiator tRNA mRNA 5 3 Start codon mRNA binding site Small ribosomal subunit 5 P site Translation initiation complex 3 EA Met Large ribosomal subunit Initiating translation

15. Fig. 17-19-1 Release factor 3 5 Stop codon (UAG, UAA, or UGA) Terminating translation

16. Fig. 17-19-2 Release factor 3 5 Stop codon (UAG, UAA, or UGA) 5 3 2 Free polypeptide 2 GDP GTP Terminating translation

17. Fig. 17-19-3 Release factor 3 5 Stop codon (UAG, UAA, or UGA) 5 3 2 Free polypeptide 2 GDP GTP 5 3 Terminating translation

18. Fig. 17-20 Growing polypeptides Completed polypeptide Incoming ribosomal subunits Start of mRNA (5 end) Polyribosome End of mRNA (3 end) (a) Ribosomes mRNA (b) 0.1 µm

19. Second mRNA base First mRNA base (5 end of codon) Third mRNA base (3 end of codon) The genetic code: -read in triplet codons -once a start codon is specified, codons are read in order (5’ to 3) until a “stop” codon is read -redundant -unambiguous -universal*

20. DNA sequence RNA sequence Amino acid sequence Protein structure and function tRNA GLN Aminoacyl-tRNA synthase (ATS GLN ) Adenylated Glutamine

21. tRNA GLN Aminoacyl-tRNA synthase (ATS GLN ) Adenylated Glutamine Altered DNA sequence Altered RNA sequence Altered (?) Amino acid sequence Altered (?) Protein structure and function

22. Fig. 5-17 Nonpolar Glycine (Gly or G) Alanine (Ala or A) Valine (Val or V) Leucine (Leu or L) Isoleucine (Ile or I ) Methionine (Met or M) Phenylalanine (Phe or F) Trypotphan (Trp or W) Proline (Pro or P) Polar Serine (Ser or S) Threonine (Thr or T) Cysteine (Cys or C) Tyrosine (Tyr or Y) Asparagine (Asn or N) Glutamine (Gln or Q) Electrically charged AcidicBasic Aspartic acid (Asp or D) Glutamic acid (Glu or E) Lysine (Lys or K) Arginine (Arg or R) Histidine (His or H) The 20 amino acids

23. Fig. 17-23a Wild type 3 DNA template strand 3 3 5 5 5 mRNA Protein Amino end Stop Carboxyl end A instead of G 3 3 3 U instead of C 5 5 5 Stop Silent (no effect on amino acid sequence)

24. Fig. 17-23a Wild type 3 DNA template strand 3 3 5 5 5 mRNA Protein Amino end Stop Carboxyl end A instead of G 3 3 3 U instead of C 5 5 5 Stop Silent (no effect on amino acid sequence)

25. Fig. 17-23b Wild type DNA template strand 3 5 mRNA Protein 5 Amino end Stop Carboxyl end 5 3 3 T instead of C A instead of G 3 3 3 5 5 5 Stop Missense

26. Fig. 17-22 Wild-type hemoglobin DNA mRNA Mutant hemoglobin DNA mRNA 3 3 3 3 3 3 5 5 5 5 5 5 CCTT T T G G A A A A AA A GG U Normal hemoglobinSickle-cell hemoglobin Glu Val

27. Fig. 17-23c Wild type DNA template strand 3 5 mRNA Protein 5 Amino end Stop Carboxyl end 5 3 3 A instead of T U instead of A 3 3 3 5 5 5 Stop Nonsense

28. Fig. 17-23e Wild type DNA template strand 3 5 mRNA Protein 5 Amino end Stop Carboxyl end 5 3 3 missing 3 3 3 5 5 5 Frameshift causing extensive missense (1 base-pair deletion)