Given the molecular masses of the following elements: H: 1 Da, C: 12 Da, N: 14 Da, O: 16 Da, which element is the most abundant in Glutamate at pH 7.0 by weight?

Question

Question 4 options:

1)

Oxygen

Nitrogen

Hydrogen

Carbon

Answer 1

At a pH of 7, Glutamate or Glutamic acid would be negatively charged, so the number of H's would be 9, not 10 or 8. That is the only thing that will change at different pH's. Not sure what the weights have to do with the problem.

Answer 2

5(12)=???? # C's
4(16)=???? # O's
1(14)=???? # N's

I should have clarified. Not sure why you couldn't really figure this out on your own.