Chapter 5 Quiz 3
In response to seasonal changes in temperature, many organisms must alter the composition of their plasma membranes to maintain the proper degree of fluidity. As summer turns to fall and eventually into winter, which of the following would you predict you would observe in the plasma membranes of organisms that are unable to regulate their body temperature? (A)a decrease in phospholipid fatty acid side chain length and a decrease in side chain saturation (B)a decrease in phospholipid fatty acid side chain length and an increase in side chain saturation (C)an increase in phospholipid fatty acid side chain length and an increase in side chain saturation (D)an increase in phospholipid fatty acid side chain length and a decrease in side chain saturation
(A)a decrease in phospholipid fatty acid side chain length and a decrease in side chain saturation
Which one of the following is considered an integral membrane protein? (A)a protein with its N-terminus in the cytoplasm and its C-terminus in the extracellular space (B)a protein attached to a transmembrane protein via hydrogen bonding (C)a protein attached to a phospholipid via ionic bonding with the head group of the lipid molecule (D)a protein capable of diffusing throughout the cytoplasm of a cell
(A)a protein with its N-terminus in the cytoplasm and its C-terminus in the extracellular space
In intestinal epithelial cells, a transport protein moves glucose into the cytoplasm against its concentration gradient at the same time that it transports Na+ into the cell down its electrochemical gradient. Which of the following CORRECTLY describes this cotransport of glucose and sodium? (A)Secondary active transport by an antiporter. (B)Secondary active transport by a symporter. (C)Primary active transport by an antiporter. (D)Primary active transport by a symporter.
(B)Secondary active transport by a symporter.
Which one of the following describes the hydrophilic component of cholesterol? (A)a phosphate group and a chemical group called choline (B)a hydroxyl group only (C)a group of four planar rings and a hydroxyl group (D)a phosphate group only (E)a single hydrocarbon tail
(B)a hydroxyl group only
The MOST abundant organic molecule in nature is: (A)cholesterol. (B)cellulose. (C)ATP. (D)aquaporin. (E)water.
(B)cellulose.
Which one of the following is moved from one side of a lysosomal membrane to the other by a transport protein in the lysosomal membrane? (A)broken-down macromolecules (B)protons and broken-down macromolecules (C)protons (D)enzymes capable of breaking down macromolecules being delivered from the Golgi apparatus
(B)protons and broken-down macromolecules
The sodium-potassium pump is an example of: (A)None of the answer options is correct. (B)channel-mediated diffusion. (C)an antiporter. (D)a symporter. (E)passive transport.
(C)an antiporter.
Specific types of lipids assemble into defined areas of a biological membrane referred to as: (A)biomembrane aggregation regions (BARs). (B)sphingopatches. (C)lipid rafts. (D)plaques. (E)cholesterol plugs.
(C)lipid rafts.
RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through: (A)budding off of the nuclear envelope. (B)aquaporins. (C)nuclear pores. (D)passive diffusion. (E)sodium-potassium pumps.
(C)nuclear pores.
The lipid components of cellular membranes often include: (A)phospholipids and fatty acids. (B)fatty acids and cholesterol. (C)phospholipids and cholesterol. (D)phospholipids.
(C)phospholipids and cholesterol.
Which of the following would be synthesized in and processed by the rough endoplasmic reticulum and Golgi apparatus? (A)fatty acids and phospholipids (B)DNA polymerase and RNA polymerase (C)cytoskeletal proteins, actin and tubulin, which are found in the cytoplasm (D)lysosomal enzymes
(D)lysosomal enzymes
Which one of the following is NOT considered part of the cytoplasm? (A)the Golgi apparatus (B)the cytoskeleton (C)the endoplasmic reticulum (D)the nucleus (E)None of the answer options is correct.
(D)the nucleus
