Question 1

Dietary triacylglycerols are digested as a result of

Accepted Answer

A) lipase action. 
B) bile salts. 
C) micelle formation. 
D) diffusion and absorption by intestinal cells. 
E) All of the above. 
A) lipase action. 
B) bile salts. 
C) micelle formation. 
D) diffusion and absorption by intestinal cells. 
E) All of the above.

Question 2

Like plasmologens,sphingolipids are found in relative abundance in

Accepted Answer

A) bacteria. 
B) plant cells. 
C) nerve cells. 
D) intestinal cells. 
E) All of the above. 
A) bacteria. 
B) plant cells. 
C) nerve cells. 
D) intestinal cells. 
E) All of the above.

Question 3

Facilitated diffusion (passive transport)through a biological membrane is

Accepted Answer

A) generally irreversible. 
B) driven by the ATP to ADP conversion. 
C) driven by a concentration gradient. 
D) endergonic. 
A) generally irreversible. 
B) driven by the ATP to ADP conversion. 
C) driven by a concentration gradient. 
D) endergonic.

Question 4

Regions on cell membranes called lipid rafts form because

Accepted Answer

A) membrane proteins form them. 
B) cholesterol preferentially associates with sphingolipids. 
C) certain membrane protein patches aggregate. 
D) cholesterol and proteins bind to form them. 
A) membrane proteins form them. 
B) cholesterol preferentially associates with sphingolipids. 
C) certain membrane protein patches aggregate. 
D) cholesterol and proteins bind to form them.

Question 5

The membrane transport protein Na+-K+ ATPase carries both Na+ and K+ ions across the plasma membrane.Typically the concentration of K+ inside cells is about 30 times higher inside the cell than outside.The concentration of Na+ is about 20 times less inside the cell than outside.Based on this information,which statement below is false?

Accepted Answer

A) The proper functioning of Na+-K+ ATPase could serve as an energy source for secondary active transport proteins. 
B) It is a symport. 
C) Transport of Na+ and K+ must be coupled to an exergonic reaction. 
D) Na+-K+ ATPase likely undergoes conformational changes during transport. 
A) The proper functioning of Na+-K+ ATPase could serve as an energy source for secondary active transport proteins. 
B) It is a symport. 
C) Transport of Na+ and K+ must be coupled to an exergonic reaction. 
D) Na+-K+ ATPase likely undergoes conformational changes during transport.

Question 6

Another name for facilitated diffusion is ________.

Accepted Answer

A) active transport 
B) transverse diffusion 
C) lateral diffusion 
D) passive transport 
A) active transport 
B) transverse diffusion 
C) lateral diffusion 
D) passive transport

Question 7

In the adenyl cyclase signaling pathway the second messenger(s)is(are)________.

Accepted Answer

A) ATP and GTP 
B) protein kinase A 
C) cyclic AMP or cyclic GMP 
D) AMP 
A) ATP and GTP 
B) protein kinase A 
C) cyclic AMP or cyclic GMP 
D) AMP

Question 8

Mitochondria differ from other cellular structures such as lysozomes or nuclei by having ________.

Accepted Answer

A) a double membrane 
B) lipid-anchored membrane proteins 
C) a high level of cholesterol in the membrane 
D) allowing the free passage of free fatty acids across the membrane 
A) a double membrane 
B) lipid-anchored membrane proteins 
C) a high level of cholesterol in the membrane 
D) allowing the free passage of free fatty acids across the membrane

Question 9

Which does not apply to the diffusion of O₂,CO₂ and small hydrophobic molecules across a membrane?

Accepted Answer

A) Diffusion is driven by the concentration gradient across the membrane. 
B) The diffusion is spontaneous and there is a decrease in free energy as diffusion occurs. 
C) The transport is saturable. 
D) Membrane proteins are not needed for the diffusion process. 
A) Diffusion is driven by the concentration gradient across the membrane. 
B) The diffusion is spontaneous and there is a decrease in free energy as diffusion occurs. 
C) The transport is saturable. 
D) Membrane proteins are not needed for the diffusion process.

Question 10

Cholesterol is converted to cholesteryl esters for ________ in cells and are ________ (more,less)hydrophobic than glycerophospholipids.

Accepted Answer

A) transport;more 
B) transport;less 
C) storage;more 
D) storage;less 
E) synthesis;more 
A) transport;more 
B) transport;less 
C) storage;more 
D) storage;less 
E) synthesis;more

Question 11

Phospholipids can move from one layer to the other in a cell membrane bilayer by

Accepted Answer

A) lateral diffusion. 
B) biosynthesis. 
C) flippases and floppases. 
D) increased diffusion. 
A) lateral diffusion. 
B) biosynthesis. 
C) flippases and floppases. 
D) increased diffusion.

Question 12

Match each technique with its purpose.
-HPLC

Accepted Answer

A) separate fatty acid esters 
B) separate neutral lipids and phospholipids 
C) separate groups of neutral lipids 
D) lateral movement of proteins in cell membranes 
E) diacylglycerol separation based on chain length and degree of unsaturation 
A) separate fatty acid esters 
B) separate neutral lipids and phospholipids 
C) separate groups of neutral lipids 
D) lateral movement of proteins in cell membranes 
E) diacylglycerol separation based on chain length and degree of unsaturation

Question 13

Fatty acids required in the diet of mammals are called

Accepted Answer

A) important. 
B) dietary. 
C) saturated. 
D) essential. 
E) esters. 
A) important. 
B) dietary. 
C) saturated. 
D) essential. 
E) esters.

Question 14

The constant Ktr is the concentration of the molecule being transported at which the transport protein is half-saturated.

Accepted Answer

A) True 
 B)False

Question 15

Which would you expect for the fatty acyl chains of the membrane phospholipids of bacteria grown at low temperature?

Accepted Answer

A) Proportion of unsaturated fatty acyl groups increases. 
B) Proportion of unsaturated fatty acyl groups decreases. 
C) No change in the proportion of saturated versus unsaturated acyl groups. 
D) More cholesterol is produced and is inserted between the fatty acyl chains of the membrane. 
A) Proportion of unsaturated fatty acyl groups increases. 
B) Proportion of unsaturated fatty acyl groups decreases. 
C) No change in the proportion of saturated versus unsaturated acyl groups. 
D) More cholesterol is produced and is inserted between the fatty acyl chains of the membrane.

Question 16

Which does not generally use a signal transduction mechanism?

Accepted Answer

A) Hydrophilic hormones. 
B) Neurotransmitters. 
C) Growth factors. 
D) Steroids. 
A) Hydrophilic hormones. 
B) Neurotransmitters. 
C) Growth factors. 
D) Steroids.

Question 17

The formation of a specialized lipid vesicle for the transport of a toxic protein out of a cell is called endocytosis.

Accepted Answer

A) True 
 B)False

Question 18

Eicosanoids participate in a variety of physiological responses and are derived from

Accepted Answer

A) waxes. 
B) arachidonic acid. 
C) cholesterol. 
D) isoprene. 
A) waxes. 
B) arachidonic acid. 
C) cholesterol. 
D) isoprene.

Question 19

Valinomycin is an antibiotic that kills bacteria by surrounding K+ ions and shuttling them down their concentration gradient and across membranes.Which might be a cause of cell death?

Accepted Answer

A) Disruption of secondary transport processes that depend on the K+ concentration gradient. 
B) Change in the pH of the bacterial cytosol. 
C) Blocking of bacterial pores with K+ ions. 
D) Massive denaturation of bacterial proteins upon change of the K+ concentration. 
A) Disruption of secondary transport processes that depend on the K+ concentration gradient. 
B) Change in the pH of the bacterial cytosol. 
C) Blocking of bacterial pores with K+ ions. 
D) Massive denaturation of bacterial proteins upon change of the K+ concentration.

Question 20

Membrane passive transport and transport by channels and pores requires ________.

Accepted Answer

A) energy input 
B) a protein carrier 
C) hexanoic acid 
D) ion gradients 
A) energy input 
B) a protein carrier 
C) hexanoic acid 
D) ion gradients

Exam 9: Lipids and Membranes

Dietary triacylglycerols are digested as a result of

Like plasmologens,sphingolipids are found in relative abundance in

Facilitated diffusion (passive transport)through a biological membrane is

Regions on cell membranes called lipid rafts form because

Another name for facilitated diffusion is ________.

In the adenyl cyclase signaling pathway the second messenger(s)is(are)________.

Mitochondria differ from other cellular structures such as lysozomes or nuclei by having ________.

Which does not apply to the diffusion of O₂,CO₂ and small hydrophobic molecules across a membrane?

Cholesterol is converted to cholesteryl esters for ________ in cells and are ________ (more,less)hydrophobic than glycerophospholipids.

Phospholipids can move from one layer to the other in a cell membrane bilayer by

Match each technique with its purpose. -HPLC

Fatty acids required in the diet of mammals are called

The constant Ktr is the concentration of the molecule being transported at which the transport protein is half-saturated.

Which would you expect for the fatty acyl chains of the membrane phospholipids of bacteria grown at low temperature?

Which does not generally use a signal transduction mechanism?

The formation of a specialized lipid vesicle for the transport of a toxic protein out of a cell is called endocytosis.

Eicosanoids participate in a variety of physiological responses and are derived from

Valinomycin is an antibiotic that kills bacteria by surrounding K+ ions and shuttling them down their concentration gradient and across membranes.Which might be a cause of cell death?

Membrane passive transport and transport by channels and pores requires ________.

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

Cholesterol is converted to cholesteryl esters for in cells and are (more,less)hydrophobic than glycerophospholipids.