Question 1

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. C

Question 2

Triacylglycerols may have either a net positive charge or a net negative charge.

Accepted Answer

A) True 
 B)False  False

Question 3

According to the current model of cell membrane structure, the two layers of lipids in the bilayer are nearly identical chemically.

Accepted Answer

A) True 
 B)False  False

Question 4

Fatty acids such as linolenate can assume a variety of steric configurations.

Accepted Answer

A) True 
 B)False

Question 5

What is the role of cholesterol in animal cell membranes?

Accepted Answer

A)  Blocks the association of the fatty acyl chains of phospholipids at high temperature. 
B)  Aids in the transport of small hydrophobic molecules across the membrane. 
C)  Is a receptor site for hormones on the surface of membranes. 
D)  Broadens the temperature range of optimum membrane fluidity. 
A)  Blocks the association of the fatty acyl chains of phospholipids at high temperature. 
B)  Aids in the transport of small hydrophobic molecules across the membrane. 
C)  Is a receptor site for hormones on the surface of membranes. 
D)  Broadens the temperature range of optimum membrane fluidity.

Question 6

Like bacteria, plants do not contain steroids.

Accepted Answer

A) True 
 B)False

Question 7

In the mitochondria phosphate ion PO43-) and H+ are transported together from the intermembrane space into the matrix. Which statement applies?

Accepted Answer

A)  The transport protein is a symport. 
B)  The transport protein must have a relatively large central channel to accommodate both ions. 
C)  The interior of the transport protein must be uncharged. 
D)  All of the above 
A)  The transport protein is a symport. 
B)  The transport protein must have a relatively large central channel to accommodate both ions. 
C)  The interior of the transport protein must be uncharged. 
D)  All of the above

Question 8

Match each lipid with the appropriate function. A) constricts blood vessels
B) synthesis of bacterial cell wall
C) smooth muscle contraction
D) leaf coatings
E) blood clotting
-bactoprenol

Accepted Answer

The answer of Match each lipid with the appropriate function....

Question 9

Match each lipid with the appropriate function. A) constricts blood vessels
B) synthesis of bacterial cell wall
C) smooth muscle contraction
D) leaf coatings
E) blood clotting
-prostaglandin E2

Accepted Answer

Question 10

Match each lipid with the appropriate function. A) constricts blood vessels
B) synthesis of bacterial cell wall
C) smooth muscle contraction
D) leaf coatings
E) blood clotting
-thromboxane A2

Accepted Answer

Question 11

The major groups of lipids can be separated by silicic acid column chromatography by eluting with

Accepted Answer

A)  silicic acid. 
B)  acetone. 
C)  chloroform, acetone and methanol. 
D)  methanol. 
E)  acetone, methanol and water. 
A)  silicic acid. 
B)  acetone. 
C)  chloroform, acetone and methanol. 
D)  methanol. 
E)  acetone, methanol and water.

Question 12

Proteins 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 13

Sterols are steroids which have

Accepted Answer

A)  a hydroxyl group at position C-17. 
B)  a hydroxyl group at position C-3. 
C)  the ability to accumulate as plaques in blood vessels. 
D)  5 fused rings instead of 4 fused rings. 
E)  hydroxyl groups at both position C-3 and C-17. 
A)  a hydroxyl group at position C-17. 
B)  a hydroxyl group at position C-3. 
C)  the ability to accumulate as plaques in blood vessels. 
D)  5 fused rings instead of 4 fused rings. 
E)  hydroxyl groups at both position C-3 and C-17.

Question 14

Which type of membrane protein might be dissociated from the membrane by changing the pH or the ionic strength?

Accepted Answer

A)  integral membrane protein 
B)  peripheral membrane protein 
C)  lipid-anchored membrane protein 
D)  All of the above 
A)  integral membrane protein 
B)  peripheral membrane protein 
C)  lipid-anchored membrane protein 
D)  All of the above

Question 15

In the adenyl cyclase signaling pathway the second messengers) isare) .

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 16

Which can serve as an energy source for secondary active transport?

Accepted Answer

A)  light 
B)  ion concentration gradient 
C)  electron transport 
D)  ATP → ADP 
A)  light 
B)  ion concentration gradient 
C)  electron transport 
D)  ATP → ADP

Question 17

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 18

Which is not involved in signal transduction?

Accepted Answer

A)  glycolytic pathway 
B)  receptor tyrosine kinases 
C)  adenylyl cyclase pathway 
D)  inositol-phospholipid pathway 
A)  glycolytic pathway 
B)  receptor tyrosine kinases 
C)  adenylyl cyclase pathway 
D)  inositol-phospholipid pathway

Question 19

Most lipids in the average human diet are

Accepted Answer

A)  unsaturated fatty acids. 
B)  saturated fatty acids. 
C)  glycerophospholipids. 
D)  triacylglycerols. 
A)  unsaturated fatty acids. 
B)  saturated fatty acids. 
C)  glycerophospholipids. 
D)  triacylglycerols.

Question 20

Polar heads of glycerophospholipids may be

Accepted Answer

A)  + charged. 
B)  - charged. 
C)  neutral. 
D)  a mixture of + and - charges, but not neutral. 
E)  All of the above 
A)  + charged. 
B)  - charged. 
C)  neutral. 
D)  a mixture of + and - charges, but not neutral. 
E)  All of the above

Exam 9: Lipids and Membranes

Facilitated diffusion passive transport) through a biological membrane is

Triacylglycerols may have either a net positive charge or a net negative charge.

According to the current model of cell membrane structure, the two layers of lipids in the bilayer are nearly identical chemically.

Fatty acids such as linolenate can assume a variety of steric configurations.

What is the role of cholesterol in animal cell membranes?

Like bacteria, plants do not contain steroids.

In the mitochondria phosphate ion PO43-) and H+ are transported together from the intermembrane space into the matrix. Which statement applies?

Match each lipid with the appropriate function. A) constricts blood vessels B) synthesis of bacterial cell wall C) smooth muscle contraction D) leaf coatings E) blood clotting -bactoprenol

Match each lipid with the appropriate function. A) constricts blood vessels B) synthesis of bacterial cell wall C) smooth muscle contraction D) leaf coatings E) blood clotting -prostaglandin E2

Match each lipid with the appropriate function. A) constricts blood vessels B) synthesis of bacterial cell wall C) smooth muscle contraction D) leaf coatings E) blood clotting -thromboxane A2

The major groups of lipids can be separated by silicic acid column chromatography by eluting with

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

Sterols are steroids which have

Which type of membrane protein might be dissociated from the membrane by changing the pH or the ionic strength?

In the adenyl cyclase signaling pathway the second messengers) isare) .

Which can serve as an energy source for secondary active transport?

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

Which is not involved in signal transduction?

Most lipids in the average human diet are

Polar heads of glycerophospholipids may be

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 Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

In the mitochondria phosphate ion PO₄³^-) and H⁺are transported together from the intermembrane space into the matrix. Which statement applies?

Match each lipid with the appropriate function. A) constricts blood vessels B) synthesis of bacterial cell wall C) smooth muscle contraction D) leaf coatings E) blood clotting -prostaglandin E₂

Match each lipid with the appropriate function. A) constricts blood vessels B) synthesis of bacterial cell wall C) smooth muscle contraction D) leaf coatings E) blood clotting -thromboxane A₂