Question 1

Which of the following best explains why triacylglycerols are a more efficient form of energy storage than glycogen in animals?

Accepted Answer

Triacylglycerols are hydrophobic and stored without water, while glycogen is highly hydrated.

Question 2

A fatty acid is described as 18:2(Δ9,12). Which of the following statements is TRUE about this molecule?

Accepted Answer

It is an unsaturated fatty acid with 18 carbons and double bonds at carbons 9 and 12.

Question 3

Which of the following is a consequence of partial hydrogenation of vegetable oils?

Accepted Answer

It converts some cis double bonds to trans double bonds, raising the melting temperature.

Question 4

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

Accepted Answer

Two fatty acids and a phosphate group attached to glycerol, with a polar head group on the phosphate.

Question 5

A patient with Tay-Sachs disease accumulates GM2 ganglioside in neurons. This is due to a deficiency in which type of enzyme?

Accepted Answer

Hexosaminidase A

Question 6

Which of the following statements about omega-3 (ω-3) fatty acids is CORRECT?

Accepted Answer

They have a double bond between C-3 and C-4 relative to the methyl (ω) end.

Question 7

Which of the following is a function of eicosanoids in the human body?

Accepted Answer

Paracrine signaling involved in inflammation and blood clotting.

Question 8

Which of the following best explains why unsaturated fatty acids have lower melting points than saturated fatty acids of the same chain length?

Accepted Answer

Cis double bonds introduce kinks, preventing tight packing of hydrocarbon chains.

Question 9

Which of the following is TRUE regarding the role of cholesterol in animal cell membranes?

Accepted Answer

It acts as a precursor for steroid hormones and bile acids.

Question 10

A researcher wants to separate a mixture of neutral lipids and membrane lipids. Which solvent system should they use for extraction?

Accepted Answer

Chloroform, methanol, and water

Question 11

Which of the following vitamins is a lipid-soluble antioxidant that protects cell membranes from oxidative damage?

Accepted Answer

Vitamin E (tocopherol)

Question 12

Which of the following best describes the function of bile acids in the digestive system?

Accepted Answer

They emulsify dietary fats, increasing their accessibility to digestive lipases.

Question 13

Which of the following statements about sphingolipids is CORRECT?

Accepted Answer

They contain a long-chain amino alcohol called sphingosine.

Question 14

A patient presents with slow blood clotting and is found to have a deficiency in a vitamin required for prothrombin formation. Which vitamin is most likely deficient?

Accepted Answer

Vitamin K

Question 15

Which of the following best describes the effect of trans fatty acids on human health?

Accepted Answer

They raise LDL cholesterol, lower HDL cholesterol, and increase inflammation.

Question 16

Which analytical technique would be most appropriate for determining the positions of double bonds in a mixture of fatty acids?

Accepted Answer

Mass spectrometry

Question 17

Which of the following is a distinguishing feature of glycolipids compared to phospholipids?

Accepted Answer

Glycolipids contain one or more sugar residues as their polar head group.

Question 18

Which of the following best describes the role of phosphatidylinositol 4,5-bisphosphate (PIP2) in cell signaling?

Accepted Answer

It is hydrolyzed by phospholipase C to produce IP3 and diacylglycerol, which act as intracellular messengers.

Question 19

Which of the following is a correct statement about the effect of chain length and degree of unsaturation on the solubility of fatty acids in water?

Accepted Answer

Increasing chain length decreases solubility, while increasing double bonds increases solubility.

Chapter 10: Lipids – Structure, Function, and Biochemical Roles

Guida di studio - Domande di pratica

Study guide - Flashcard