QUESTION 97 Vancomycin O interferes with the action of the lipid carrier that transports peptidoglycan precursors across the plasma membrane. O inhibits the transpeptidation reaction in peptidoglycan biosynthesis. O blocks the addition of the pentapeptide chain during peptidoglycan biosynthesis. O inhibits the transglycosylase reaction in peptidoglycan biosynthesis.

Question 4 There are many functions of enzymes that are essential for cellular processes. A ligase is used to O split larger molecules with the use of water. split a compound by using water. removes electrons from an element. O join two molecules. Question 5 Apoenzymes are always active. inactive when they are not bound to their cofactors and/or coenzymes. built from holoenzymes. O found only in eukaryotic cells. Question 6 Allosteric inhibitors will change the shape of the substrate so that enzymatic function increases. change the shape of the substrate so that enzymatic function decreases. change the shape of the enzyme so that enzymatic function decreases. change the shape of the enzyme so that enzymatic function increases.

Question 34 The biosynthesis of amino acids can only be carried out by: O nitrogen-fixing bacteria Oplants O fungi O bacteria, plants, and fungi O the biosynthesis of amino acids can only be carried out by all organisms

QUESTION 1 You have a crude lysate sample (CL) containing a mixture of six proteins (1, 2, 3, 4, 5, ẞ- galactosidase), and your goal is to obtain purified ẞ-gal. Some characteristics of these proteins are shown in the table below. Protein Alcohol dehydrogenase Carbonic anhydrase Insulin B chain Phosphorylase B Glutamic dehydrogenase B-galactosidase Concentration of ammonium sulfate (AS) required for precipitation Molecular Weight (kDa) Isoelectric point (pl) 45% 38 3.7 80% 65% 20% 30% 45% 28 4.8 4 5.3 98 68 49 9.5 115 5.3 You begin your purification by performing an ammonium sulfate (AS) precipitation. You add the appropriate concentration of AS to your CL sample, incubate overnight at 4°C, then centrifuge to generate a supernatant (AS-S) and pellet (AS-P). What concentration of AS will you use to precipitate ẞ-galactosidase? O 20% O 30% O 45% 65% O 80%