CHEM 1005 Unit 1 Practice Evaluation Set. Questions and Answers Graded A+

CHEM 1005 Unit 1 Practice Evaluation Set. Questions and Answers Graded A+ Hemoglobin binds oxygen with a greater affinity in the: - CORRECT ANSWER-R state Hemoglobin bound to heme is termed a holoprotein. The heme or porphoryin ring is required for oxygen binding and it is termed a: - CORRECT ANSWER-prosthetic group Alpha helices and beta sheets are primarily stabilized by: - CORRECT ANSWER-H bonding Ligases are a class of enzymes characterized by their ability to: - CORRECT ANSWER-synthesize bonds between carbon atoms and an additional atom that is involved in the cleavage of a high energy bond. An enzyme inhibitor that increases the Km but does not change the Vmax is classified as: - CORRECT ANSWER-competitive inhibitor Cleavage of fructose 1, 6 bisphosphate to dihydroxyacetone and glyceraldehyde 3-phosphate is achieved by what class of enzymes: - CORRECT ANSWER-lyase Enzymes reduce the activation energy for a reaction. All enzymes do this by: - CORRECT ANSWER-providing an active site most complementary the transition state, Enzymes help to reduce the activation energy of a reaction by stabilizing high energy intermediates. By have a flexible active site that is highly complementary to the transition state of a substrate this is most readily achieved. The activity of an enzyme is increased when the enzyme is phosphorylated on an exposed tyrosine residue. Phosphorylation of this amino acid is classified as which of the following? - CORRECT ANSWER-covalent modification, Phosphorylation is a covlanet modification to an enzyme that can increase or decrease the activity of an enzyme. Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen phosphorylase. This is an example of which of the follow types of enzyme regulation? - CORRECT ANSWER-allosteric activation Which of the following is an example of enzyme regulation through covalent modification? - CORRECT ANSWER-Phosphorylation of muscle glycogen phosphorylase Movement of ammonia from an amino acid to an alpha-keto acid involves a family of enzymes best categorized as: - CORRECT ANSWER-Transferases An alpha-helical arrangement of amino acids is considered to be part of what level of protein structure? - CORRECT ANSWER-secondary structure of the protein An example of enzyme activation by cleavage is best illustrated by which of the following? - CORRECT ANSWER-activation of chymotrypsinogen to chymotrypsin