Question 1

Which of the following best explains why triacylglycerols are the preferred energy storage molecules in mammals compared to glycogen?

Accepted Answer

Triacylglycerols are highly reduced and anhydrous, allowing for more energy storage per gram.

Question 2

Which of the following is NOT a source of triacylglycerols in the human body?

Accepted Answer

Direct absorption from the large intestine

Question 3

What is the primary role of bile salts in lipid digestion?

Accepted Answer

They act as amphipathic detergents to solubilize dietary fats into micelles.

Question 4

Which enzyme is responsible for hydrolyzing triacylglycerols in the capillaries, allowing fatty acids to be taken up by tissues?

Accepted Answer

Lipoprotein lipase

Question 5

A patient with a genetic defect in apolipoprotein B-100 would most likely have impaired:

Accepted Answer

Uptake of LDL particles by peripheral cells

Question 6

Which of the following best describes the fate of fatty acids released from adipocytes during fasting?

Accepted Answer

They are transported in the blood bound to serum albumin.

Question 7

Which of the following statements about LDL and HDL is CORRECT?

Accepted Answer

LDL delivers cholesterol to peripheral tissues, while HDL returns cholesterol to the liver.

Question 8

Which of the following events is most directly associated with the development of atherosclerotic plaques?

Accepted Answer

Oxidation of LDL particles and uptake by macrophages to form foam cells

Question 9

Which hormone stimulates the mobilization of triacylglycerols from adipose tissue during fasting?

Accepted Answer

Glucagon

Question 10

What is the correct sequence of events for the digestion and absorption of dietary fats?

Accepted Answer

Emulsification by bile salts → hydrolysis by pancreatic lipase → formation of micelles → absorption by intestinal mucosa

Question 11

Which of the following equations best represents the hydrolysis of a triacylglycerol molecule?

Accepted Answer

$$\mathrm{Triacylglycerol} + 3\ H_2O \rightarrow 3\ \mathrm{Fatty\ acids} + \mathrm{Glycerol}$$

Question 12

A mutation that decreases the synthesis of LDL receptors would most likely result in which of the following?

Accepted Answer

Increased plasma LDL levels and higher risk of atherosclerosis

Question 13

Which of the following best describes the role of chylomicrons in lipid transport?

Accepted Answer

They transport dietary triacylglycerols from the intestine to peripheral tissues via the lymph and blood.

Question 14

Which of the following is a direct consequence of the action of hormone-sensitive lipase (HSL) in adipocytes?

Accepted Answer

Release of free fatty acids into the bloodstream

Question 15

Which of the following statements about the structure of plasma lipoproteins is CORRECT?

Accepted Answer

The hydrophobic core contains cholesterol esters and triacylglycerols, while the surface is composed of phospholipids, cholesterol, and proteins.

Question 16

Which of the following best explains why the brain cannot use fatty acids as a direct energy source?

Accepted Answer

Fatty acids cannot cross the blood-brain barrier.

Question 17

Which of the following steps is regulated by Protein Kinase A (PKA) during the mobilization of triacylglycerols in adipose tissue?

Accepted Answer

Phosphorylation and activation of hormone-sensitive lipase (HSL)

Question 18

Which of the following best describes the fate of chylomicron remnants after delivering dietary fats to tissues?

Accepted Answer

They are taken up by the liver for further processing.

Question 19

Which of the following is a correct description of the endogenous pathway of lipid transport?

Accepted Answer

VLDL particles synthesized in the liver transport triacylglycerols to peripheral tissues.

Question 20

Which of the following is the correct order of lipases involved in the complete hydrolysis of triacylglycerols in adipocytes?

Accepted Answer

ATGL → HSL → MGL

Lipid Transport and Utilization in Biochemistry

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