I chose answer A and it was incorrect below Please explain t

I chose answer A and it was incorrect. (below) Please explain the correct answer and why?

I chose answer B and it was incorrect. (below) Please explain the correct answer and why?

8. Pyrophosphatase is an enzyme that breaks down pyrophosphate (shown at right: 2 covalently attached phosphates, highly negatively charged, this is a leftover product each time a nucleotide is added to the 3 end of DNA or RNA), generating 2 phosphate molecules. In studying a novel pyrophosphatase enzyme, you have discovered a clever way by which cells modulate the activity of the enzyme: the active site of the enzyme is bordered by a pair of serine residues that can be phosphorylated by a regulatory kinase. Phosphorylation of the 2 serines has no effect on catalytic efficiency of the enzyme active site, but the phosphorylated serines introduce a local negative charge around the mouth of the active site, which partially repels pyrophosphate substrate molecules as they approach. In Michaelis-Menten terms, how would phosphorylation at the described serines change the performance of the pyrophosphatase enzyme? A) Vmax will decrease, Km w remain the same B) Vmax will stay the same, Km will increase. C) Vmax will decrease, Km will decrease D) max will stay the same, Km will decrease. V

Solution

It shows competitive inhibition as active site of enzyme is bordered by serine residues so according to Michaelis-Menten terms, option B is

Answer2:

Option D is correct, wiithoutnucleosomedisassembly, it is impossible to get promoter configurations that are completely free of nucleosomes. This fact is supported by our simulation results when only the sliding event is considered in the model