Based on the four amino acid structures shown select the FALSE statement. (see attachment for structures) Possible Answers a. Amino acids A B and D have three ionizable groups each. b. Amino acids A B and D have sidechains capable of forming hydrogen bonds. c. Amino acid D is aromatic. d. Amino acid A has a basic side chain. e. Amino acids A and C have nonpolar aliphatic sidechains. 2. Aqueous Biochemistry The pH of a sample of blood is 7.4 . The pH of a sample of gastric juice is 1.4 . The blood sample has: Possible Answers a. 6 times lower [H+] than the gastric juice. b. 6000 times lower [H+] than the gastric juice. c. A million times lower [H+] than the gastric juice. d. 0.189 times lower [H+] than the gastric juice. e. 5.29 times lower [H+] than the gastric juice. 3. Amino Acid Properties 5 The amino acids with alcohol side chains are: Possible Answers a. serine and asparagine b. glutamine and cysteine c. serine and threonine d. histidine and tyrosine e. tyrosine and tryptophan 4. H-bonding in Biomolecules 2 Which statement about hydrogen bonds is TRUE? (Consider only the side chain of the amino acid.) Possible Answers a. Serine is only a hydrogen bond acceptor and not a H-bond donor b. Lysine at pH=7 is only a hydrogen bond donor and not a H-bond acceptor c. basepairing in DNA is not affected by pH since the protonation states of the bases do not affect Watson-Crick basepairing d. a carboxylic acid group is primarily a donor at high pH e. an amino group is primarily an acceptor at low pH 5. Aqueous Biochemistry 6 If a molecule has a pKa of 8 and the pH is 6 the percentage of A- is closest to: Possible Answers a. 99% b. 90% c. 50% d. 10% e. 1%