Lipid Metabolism: Online Quizzes and Study Resources

Question 1

Ketone bodies are produced during periods of fasting or starvation. What is their primary role in energy metabolism?

Accepted Answer

Ketone bodies are the primary energy source for the brain when glucose is scarce.

Answer

Ketone bodies are stored in adipose tissue and released during exercise.

Answer

Ketone bodies are synthesized in muscle tissue and transported to the liver for energy production.

Answer

Ketone bodies are used to synthesize glucose in the liver during fasting and starvation.

Question 2

Which step is NOT involved in the β-oxidation of fatty acids?

Accepted Answer

Hydrolysis

Answer

Dehydration

Answer

Thiolysis

Answer

Enoyl-CoA reduction

Question 3

The primary site of fatty acid synthesis in mammals is the:

Accepted Answer

Liver

Answer

Adipose tissue

Answer

Skeletal muscle

Answer

Brain

Question 4

Which enzyme catalyzes the rate-limiting step in cholesterol synthesis?

Accepted Answer

HMG-CoA reductase

Answer

ACAT

Answer

LDLR

Answer

PCSK9

Question 5

What is the primary function of ketone bodies?

Accepted Answer

Energy source for the heart and brain during starvation

Answer

Storage form of lipids

Answer

Hormonal regulators of lipid metabolism

Answer

Precursors for cholesterol synthesis

Question 6

Which of the following lipoproteins transports cholesterol from the liver to peripheral tissues?

Accepted Answer

LDL

Answer

VLDL

Answer

HDL

Answer

IDL

Question 7

What is the main regulatory mechanism for fatty acid synthesis?

Accepted Answer

Feedback inhibition by malonyl-CoA

Answer

Activation by insulin

Answer

Inhibition by glucagon

Answer

Regulation by AMP-activated protein kinase (AMPK)

Question 8

What is the name of the enzyme that catalyzes the hydrolysis of triglycerides in adipose tissue?

Accepted Answer

Lipase

Answer

Protease

Answer

Amylase

Answer

Nuclease

Question 9

Which of the following is a common lipid-lowering drug that targets HMG-CoA reductase?

Accepted Answer

Statin

Answer

Ezetimibe

Answer

Niacin

Answer

Fibrate

Question 10

How does HMG-CoA reductase regulate cholesterol synthesis?

Accepted Answer

HMG-CoA reductase is inhibited by high cholesterol levels, decreasing cholesterol synthesis.

Answer

HMG-CoA reductase is activated by high cholesterol levels, increasing cholesterol synthesis.

Answer

HMG-CoA reductase is not affected by cholesterol levels.

Answer

HMG-CoA reductase converts LDL to HDL.

Question 11

Which transcription factor plays the primary role in regulating fatty acid synthesis?

Accepted Answer

SREBP-1

Answer

NF-κB

Answer

PPAR-α

Question 12

Which of the following is NOT a primary pathway for lipid metabolism?

Accepted Answer

Glycolysis

Answer

Fatty acid synthesis

Answer

Cholesterol metabolism

Answer

Fatty acid oxidation

Question 13

The enzyme responsible for initiating fatty acid oxidation is:

Accepted Answer

Acyl-CoA dehydrogenase

Answer

Carnitine palmitoyltransferase I

Answer

β-ketoacyl-CoA thiolase

Answer

Lipoprotein lipase

Question 14

Which of the following hormones primarily regulates fatty acid synthesis?

Accepted Answer

Insulin

Answer

Thyroid hormone

Answer

Growth hormone

Answer

Epinephrine

Question 15

The primary site of cholesterol synthesis in the body is the:

Accepted Answer

Liver

Answer

Adipose tissue

Answer

Small intestine

Answer

Skeletal muscle

Question 16

A ketone body produced in the liver during periods of fasting is:

Accepted Answer

Acetoacetate

Answer

Triglyceride

Answer

Amino acid

Answer

Glycogen

Question 17

Which of the following is a risk factor for developing hyperlipidemia?

Accepted Answer

Obesity

Answer

Regular exercise

Answer

Healthy diet

Answer

Non-smoking

Question 18

The measurement of blood levels of LDL cholesterol is primarily used to assess:

Accepted Answer

Cardiovascular disease risk

Answer

Liver function

Answer

Renal function

Answer

Thyroid function

Question 19

A class of drugs commonly used to lower LDL cholesterol levels is:

Accepted Answer

Statin

Answer

Aspirin

Answer

Metformin

Answer

Levothyroxine

Question 20

Emerging research has identified a potential link between lipid metabolism and:

Accepted Answer

Metabolic syndrome

Answer

Asthma

Answer

Lupus

Answer

Parkinson's disease

Question 21

Which of the following is the primary site of fatty acid oxidation?

Accepted Answer

Mitochondria

Answer

Endoplasmic reticulum

Answer

Cytosol

Answer

Peroxisome

Question 22

Which of the following is a key regulator of fatty acid metabolism?

Accepted Answer

Insulin

Answer

Glucagon

Answer

Epinephrine

Answer

Somatotropin

Question 23

Which of the following is the precursor molecule for cholesterol synthesis?

Accepted Answer

Acetyl-CoA

Answer

Phosphatidylcholine

Answer

Malonyl-CoA

Answer

Isopentenyl pyrophosphate

Question 24

The process by which lipids are transported in the blood is known as:

Accepted Answer

Lipoprotein metabolism

Answer

Krebs cycle

Answer

Gluconeogenesis

Answer

Glycolysis

Question 25

Which of the following is a characteristic of high-density lipoprotein (HDL)?

Accepted Answer

Transports cholesterol from tissues to the liver

Answer

Is associated with an increased risk of cardiovascular disease

Answer

Transports triglycerides from the liver to tissues

Answer

Contains a high proportion of apolipoprotein B

Question 26

The enzyme that catalyzes the first step of cholesterol degradation is:

Accepted Answer

Cholesterol 7-alpha-hydroxylase

Answer

Fatty acyl-CoA synthase

Answer

Lipase

Answer

3-hydroxy-3-methylglutaryl-CoA reductase

Question 27

Which of the following conditions is characterized by elevated levels of triglycerides in the blood?

Accepted Answer

Hypertriglyceridemia

Answer

Hypocholesterolemia

Answer

Hypercholesterolemia

Question 28

The main function of the bile acids is to:

Accepted Answer

Facilitate the digestion and absorption of lipids

Answer

Transport cholesterol from the liver to tissues

Answer

Regulate blood glucose levels

Answer

Stimulate the release of insulin