SOLVED

41) What is the common name of the following glycose shown in Fischer notation? A) D-glyceraldehyde B) L-glyceraldehyde C) s-glyceraldehyde D) (-)-glyceraldehyde E) D-erythrose 42) Which of the following compounds may display the property of optical isomerism? A) 3-pentanol B) 2-pentene C) 2-bromopropane D) 2-bromobutane E) acetone 43) Choose the INCORRECT prediction. By careful inspection of the formula of lactic acid, CH3CH(OH)COOH, one would predict: A) Molecules should have two forms. These forms are mirror images of one another. B) Molecule should show cis and trans isomerism. C) Molecule should have a chiral carbon atom. D) Molecule should show optical isomerism. E) Molecule should show acidic properties. 44) Cellulose and starch are both polymers of glucose units, but most animals can only use starch as a source of carbohydrate in their diets. Why are most animals incapable of digesting cellulose? A) Starch contains α linkages between carbons 1 and 4, where as cellulose contains β linkages between carbons 1 and 2. B) This statement is incorrect. Most animals can digest cellulose. C) The polymer of cellulose is simply too long to be completely digested by animals. D) Most animals do not produce enzymes which are capable of hydrolyzing β linkages between glycoses. E) The glucose units of cellulose are in the open chain form and cannot be hydrolyzed by the cyclic-sugar specific enzymes of animals. 45) Which of the following is unimportant for tertiary structure of the proteins? A) peptide bonds B) salt linkages C) hydrogen bonding D) disulfide linkages 46) Choose the INCORRECT statement. A) Peptides are amino acids joined by a peptide bond. B) A tripeptide has three peptide bonds. C) A protein is hydrolyzed to a mixture of α-amino acids. D) An α-amino acid is a carboxylic acid with an amine group on the α carbon. E) Proteins are a polymer of amino acid units. 47) Choose the INCORRECT statement. A) Proteins make up the bulk of the body’s nonskeletal structure. B) Enzymes are carbohydrates which speed up reactions. C) Except glycine, naturally occurring amino acids are optically active. D) Essential amino acids are necessary for proper health and growth. E) Essential amino acids must be ingested through foods because the body is unable to synthesize them. 48) Choose the INCORRECT statement. A) Amino acids can exist as dipolar ions. B) Dipolar ions are also called zwitterion. C) Isoelectric point is the pH at which an amino acid becomes a cation. D) Two amino acids joined by the elimination of a water molecule is a dipeptide. E) A large polypeptide of more than 10,000 U is called a protein. 49) Choose the INCORRECT statement. A) The bond between amino acids is called a peptide bond. B) There are four levels of structure in a protein. C) Primary structure is the order of the amino acids in the chain. D) Secondary structure is the bonding of more than one protein together. E) Enzymes are biological catalysts that contain protein. 50) Which of the following examples of protein structure would be classified as the tertiary structure of a protein? A) β-pleated sheet B) gly-leu-trp-lys-lys-arg-met C) three identical subunits D) an elongated α-helix between two β-pleated sheets E) amorphous, globular peptide