Q1. The basic structural unit of a biomembrane is the phospholipid bilayer. Acetic acid and ethanol are each collected of two carbons, hydrogen and oxygen, and both enter cells by passive diffusion. At pH 7′ one is much more membrane permeable than the other’ that is more permeable and why? Calculate how the permeability of each is altered when the pH is reduced to 1.0, a value typical of the stomach.

Q2. Suppose that in particular protein made up of 564 amino acids, a lysine residue at position 17 is replaced by asparagine. Would you expect this change to demolish the function of this protein? Explain briefly.