Question 1

Which of the following best explains why triglycerides are a more efficient energy storage molecule than glycogen in humans?

Accepted Answer

Triglycerides are more reduced than glucose, so they contain more energy per gram.

Question 2

Which of the following statements about unsaturated fatty acids is TRUE?

Accepted Answer

They have at least one double bond in the carbon chain.

Question 3

A fatty acid with the notation $$18:2\$$Delta^{9,12}$$ has which of the following characteristics?

Accepted Answer

18 carbons, 2 double bonds at carbons 9 and 12 from the carboxyl end.

Question 4

Why are trans fatty acids considered more harmful than cis fatty acids?

Accepted Answer

Trans fatty acids raise LDL cholesterol and lower HDL cholesterol, increasing cardiovascular risk.

Question 5

Which of the following is a disadvantage of storing energy as triglycerides in adipose tissue?

Accepted Answer

Triglycerides are insoluble in water and must be transported in the blood by specialized proteins.

Question 6

Which of the following best describes the structure of a glycerophospholipid?

Accepted Answer

A glycerol backbone with two fatty acids and a phosphate group attached to an alcohol.

Question 7

Which of the following is TRUE regarding the head groups of membrane lipids?

Accepted Answer

Glycolipids have sugars attached to glycerol or sphingosine through a glycosidic bond.

Question 8

Which of the following statements about the ABO blood group antigens is CORRECT?

Accepted Answer

The A antigen is produced by adding a terminal N-acetylgalactosamine to the O antigen.

Question 9

Why can people who are AB+ receive blood from any donor type?

Accepted Answer

They lack antibodies against A, B, and Rh antigens.

Question 10

Which of the following is a function of cholesterol in biological membranes?

Accepted Answer

It increases membrane fluidity at low temperatures and decreases it at high temperatures.

Question 11

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

The hydrophobic effect causes the fatty acid tails to avoid water, while the polar head groups interact with water.

Question 12

Which of the following statements about essential fatty acids is TRUE?

Accepted Answer

They must be obtained from the diet because humans cannot synthesize them.

Question 13

Which of the following is a reason why margarine is more solid at room temperature than vegetable oil?

Accepted Answer

Margarine contains more trans double bonds due to partial hydrogenation.

Question 14

Which of the following best describes the difference between sphingolipids and glycerophospholipids?

Accepted Answer

Sphingolipids have a sphingosine backbone, while glycerophospholipids have a glycerol backbone.

Question 15

Which of the following is TRUE about the role of sphingomyelin in neurons?

Accepted Answer

Sphingomyelin is found in myelin sheaths and helps insulate axons to prevent charge leakage.

Question 16

Which of the following is a property of fatty acids with cis double bonds?

Accepted Answer

They have kinks in their structure, resulting in lower melting points.

Question 17

Which of the following is TRUE regarding the transport of fatty acids in the blood?

Accepted Answer

Fatty acids are bound to specialized proteins such as albumin for transport.

Question 18

Which of the following statements about sterol hormones is CORRECT?

Accepted Answer

Sterol hormones can diffuse through the nuclear membrane and regulate gene expression.

Question 19

Which of the following is a function of phospholipase enzymes in cells?

Accepted Answer

They degrade membrane lipids in response to extracellular signals.

exam 4 Chapter 10-lipids

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