ECPI BIO 111 EXAM 2 NEWEST 2026-2027
ACTUAL EXAM COMPLETE 80 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) ALREADY GRADED A+ BRAND
NEW!!
1) For a protein to be an integral membrane protein, it would have to be _____. - CORRECT
ANSWER: amphipathic, with at least one hydrophobic region
2) You have a planar bilayer with equal amounts of saturated and unsaturated phospholipids.
After testing the permeability of this membrane to glucose, you increase the proportion of
unsaturated phospholipids in the bilayer. What will happen to the membrane's permeability to
glucose? - CORRECT ANSWER: Permeability to glucose will increase.
3) According to the fluid mosaic model of cell membranes, phospholipids _____. - CORRECT
ANSWER: A) can move laterally along the plane of the membrane
4) The membranes of winter wheat are able to remain fluid when it is extremely cold by _____. -
CORRECT ANSWER: A) increasing the percentage of unsaturated phospholipids in the
membrane
5) Some regions of the plasma membrane, called lipid rafts, have a higher concentration of
cholesterol molecules. At higher temperatures, these regions _____. - CORRECT ANSWER: B)
are less fluid than the surrounding membrane
6) Singer and Nicolson's fluid mosaic model of the membrane proposed that membranes_____. -
CORRECT ANSWER: C) consist of protein molecules embedded in a fluid bilayer of
phospholipids
7) An animal cell lacking oligosaccharides on the external surface of its plasma membrane would
likely be impaired in which function? - CORRECT ANSWER: B) cell-cell recognition
, 8) Which of these are NOT embedded in the hydrophobic portion of the lipid bilayer at all? -
CORRECT ANSWER: C) peripheral proteins
9) Why are lipids and proteins free to move laterally in membranes? - CORRECT ANSWER: D)
There are only weak hydrophobic interactions in the interior of the membrane.
15) Cell membranes are asymmetrical. Which of the following statements is the most likely
explanation for the membrane's asymmetrical nature? - CORRECT ANSWER: C) The two sides
of a cell membrane face different environments and carry out different functions.
16) In what way do the membranes of a eukaryotic cell vary? - CORRECT ANSWER: B)
Certain proteins are unique to each membrane.
17) Which of the following is a reasonable explanation for why unsaturated fatty acids help keep
a membrane more fluid at lower temperatures? - CORRECT ANSWER: A) The double bonds
form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.
18) What kinds of molecules pass through a cell membrane most easily? - CORRECT
ANSWER: B) small and hydrophobic
19) Which of the following most accurately describes selective permeability? - CORRECT
ANSWER: D) Only certain molecules can cross a cell membrane.
20) Which of the following is a characteristic feature of a carrier protein in a plasma membrane?
- CORRECT ANSWER: A) It exhibits a specificity for a particular type of molecule.
21) Which of the following would likely move through the lipid bilayer of a plasma membrane
most rapidly? - CORRECT ANSWER: A) CO2
ACTUAL EXAM COMPLETE 80 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) ALREADY GRADED A+ BRAND
NEW!!
1) For a protein to be an integral membrane protein, it would have to be _____. - CORRECT
ANSWER: amphipathic, with at least one hydrophobic region
2) You have a planar bilayer with equal amounts of saturated and unsaturated phospholipids.
After testing the permeability of this membrane to glucose, you increase the proportion of
unsaturated phospholipids in the bilayer. What will happen to the membrane's permeability to
glucose? - CORRECT ANSWER: Permeability to glucose will increase.
3) According to the fluid mosaic model of cell membranes, phospholipids _____. - CORRECT
ANSWER: A) can move laterally along the plane of the membrane
4) The membranes of winter wheat are able to remain fluid when it is extremely cold by _____. -
CORRECT ANSWER: A) increasing the percentage of unsaturated phospholipids in the
membrane
5) Some regions of the plasma membrane, called lipid rafts, have a higher concentration of
cholesterol molecules. At higher temperatures, these regions _____. - CORRECT ANSWER: B)
are less fluid than the surrounding membrane
6) Singer and Nicolson's fluid mosaic model of the membrane proposed that membranes_____. -
CORRECT ANSWER: C) consist of protein molecules embedded in a fluid bilayer of
phospholipids
7) An animal cell lacking oligosaccharides on the external surface of its plasma membrane would
likely be impaired in which function? - CORRECT ANSWER: B) cell-cell recognition
, 8) Which of these are NOT embedded in the hydrophobic portion of the lipid bilayer at all? -
CORRECT ANSWER: C) peripheral proteins
9) Why are lipids and proteins free to move laterally in membranes? - CORRECT ANSWER: D)
There are only weak hydrophobic interactions in the interior of the membrane.
15) Cell membranes are asymmetrical. Which of the following statements is the most likely
explanation for the membrane's asymmetrical nature? - CORRECT ANSWER: C) The two sides
of a cell membrane face different environments and carry out different functions.
16) In what way do the membranes of a eukaryotic cell vary? - CORRECT ANSWER: B)
Certain proteins are unique to each membrane.
17) Which of the following is a reasonable explanation for why unsaturated fatty acids help keep
a membrane more fluid at lower temperatures? - CORRECT ANSWER: A) The double bonds
form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.
18) What kinds of molecules pass through a cell membrane most easily? - CORRECT
ANSWER: B) small and hydrophobic
19) Which of the following most accurately describes selective permeability? - CORRECT
ANSWER: D) Only certain molecules can cross a cell membrane.
20) Which of the following is a characteristic feature of a carrier protein in a plasma membrane?
- CORRECT ANSWER: A) It exhibits a specificity for a particular type of molecule.
21) Which of the following would likely move through the lipid bilayer of a plasma membrane
most rapidly? - CORRECT ANSWER: A) CO2
