AP Biology: Final Exam Review (Unit One)

2. For this pair of items, choose the option that best describes their relationship. (A) The probability that amino acids with polar side chains are hydrophobic. (B) The probability that fatty acids are hydrophobic. A) Item (A) is less than item (B). B) Item (A) is greater than item (B). C) Item (A) is exactly or very approximately equal to item (B). D) Item (A) may stand in more than one of the above relations to item (B)

A) Item (A) is less than item (B).

Researchers compared similar proteins from related organisms in different habitats. They found that the proteins from organisms living in harsh environments had a greater number of cysteine amino acids than did proteins from organisms not living in harsh environments. The structure of cysteine is shown. Bonds can form between the sulfur atom of different cysteine amino acids (s- bonds). Figure 1. Chemical structure of cysteine Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins? A) The change has no effect on the stability of the protein because only one type of amino acid is involved. B) The change leads to increased protein stability because of an increased number of bonds in the tertiary structure of the proteins. C) The change leads to decreased protein stability because of an increased number of bonds in the tertiary structure of the proteins. D) The change leads to increased protein stability only when the added cysteine amino acids are next to other cysteine amino acids in the primary structure.

B) The change leads to increased protein stability because of an increased number of bonds in the tertiary structure of the proteins.

3. Which of the following is not a polymer? A) DNA B) starch C) cellulose D) glucose

D) glucose

refer to online packet

refer to online packet