Allosterically Regulated

I have attached the five questions and my proposed answers. Please look over them and if they are incorrect, please correct them. I appreciate the help.

1. Since allosteric proteins change shape, in order to perform other biological functions and bind with cofactors, I would say the primary level of protein structure, answer A.

2.I think the answer is B because of catlysis of of phosphorylation of substrates by transferring a phosphate from ATP. There is no mention of sulfur groups.

3. I would chose a B, because the regulatory site of an enzyme is the binding site for non-competitive inhibitors.

4.Not quite sure

5. According to Michaelis-Menton, Km is the substrate concentration which yields half-maximal velocity, where as Vmax is the maximum velocity. Non-competitive inhibition yields a change in the shape of an enzyme.This reduces the concentration of 'active' enzyme resulting in a decrease in the Vmax. Thus I would chose answer E

Question #1: (0.8 point)
Which level of structure must a protein have to be allosterically regulated?
a.) Primary
b.) Secondary
c.) Tertiary
d.) Quaternary
e.) All of the above

Question #2: (0.8 point)
Which of the following is not a mechanism of enzyme regulation?
a.) Feedback inhibition by product.
b.) Addition or removal of phosphate groups to amino acids with sulfur groups.
c.) Stimulation by a substrate or product.
d.) Proteolytic cleavage
e.) None of the above

Question #3: (0.8 point)
Which of these is NOT a function or capability of the active site of an enzyme?
a.) Substrate binding
b.) Binding of a necessary cofactor
b.) Binding a non-competitive inhibitor
c.) None of the above
d.) All of the above

Question #4: (0.8 point)
The Km of an enzyme:
a.) is equal to the maximal velocity of an enzyme
b.) is a hypothetical number that cannot be determined experimentally
c.) is negatively affected by a non-competitive inhibitor
d.) is a measure of how tightly an enzyme binds to its substrate
e.) all of the above

Question #5: (0.8 point)
Vmax:
a.) is the maximal velocity at which an enzyme can function
b.) is reduced by a non-competitive inhibitor
c.) is determined on a Lineweaver-Burke plot by taking the reciprocal of the y-intercept
d.) is high for an enzyme with a high Km and low substrate affinity
e.) all of the above