Question #1: Which of the following describes myoglobin? a.) Maternal myoglobin
ID: 58056 • Letter: Q
Question
Question #1: Which of the following describes myoglobin?
a.) Maternal myoglobin binds less tightly to oxygen than fetal myoglobin.
b.) It is a multi-subunit protein with four heme groups for oxygen binding.
c.) 1,2-bisphosphoglycerate decreases its affinity for oxygen.
d.) All of the above.
e.) None of the above.
Question #2: A competitive inhibitor is an excellent example of a chemical that can be used to control protein activity by reduction of Vmax.
a.) True
b.) False
Question #3: Allosteric inhibition is neither competitive nor non-competitive because the inhibitor does not bind to the active site or reduce the Vmax of the enzyme.
a.) True
b.) False
Question #4:Which is true about the R form of an allosteric enzyme?
a.) Is stabilized by an allosteric inhibitor
b.) Is the inactive form of the enzymatic subunit
c.) Is destabilized by an allosteric activator
d.) Is the form of the enzyme that can catalyze the formation of an enzymatic product
e.) Both a an c
Explanation / Answer
Answer 1a) Maternal myoglobin binds less tightly to oxygen than fetal myoglobin.
Explanation - Myoglobin is a monomeric hemoprotein, which contains a single heme group for oxygen binding. it has been seen that maternal myoglobin binds has the lower affinity for oxygen than the fetal myoglobin because the fetus has to take oxygen from the maternal environment, therefore, the binding affinity of maternal hemoglobin would be lower for oxygen such that it can easily pass on the oxygen to the developing fetus.
Answer 2b) False
Reason - In competitive inhibition, the Vmax of the reaction remains unchanged, while the dissociation constant for the substrate is increased as a result of a decrease in apparent binding affinity of the substrate to the active site on the enzyme.