Question 16 Two peptides have almost the exact same primary structure, except that one has about 10 fewer amino acids at the amino-terminus (N-terminus) of the protein. What is a possible explanation for the protein that is missing those 10 amino acids? O A. An alternative Poly-A tail addition site O B. Leaky scanning occurred O.Differential glycosylation of the protein O D. Inefficient folding by chaperone proteins O E. All of the above are correct answers

QUESTION 25 Phosphorylation, acetylation, methylation, and ubiquitylation are all ways to: Regulate carbohydrates using small molecules O Turn on and off the activity of proteins O Remove amino acids from proteins O Join proteins together

Question 14 If two proteins have the same sequence of amino acids, which type of protein structure must they have in common? O Primary structure O secondary structure O Quaternary structure O tertiary structure

QUESTION 32 Aquaporins are proteins that control the passage of water molecules across a cell membrane. The protein forms a pore, or opening, in the membrane. You isolate what you think are two different molecules of aquaporin and determine that one of the proteins has a larger pore diameter than the second. Which of the following do you conclude? These two forms of aquaporin will have identical sequences of amino acids. These two forms of aquaporin will have different sequences of amino acids. You will have to sequence the proteins to compare their primary structure, because it should have no effect on pore diameter. These two forms of aquaporin have identical primary structure but differ in their tertiary structure.