Lipid Metabolism: A Comprehensive Guide for Advanced Diploma in Healthcare Students

Question 1

Which of the following is NOT a consequence of dysregulated lipid metabolism that contributes to cardiovascular diseases?

Accepted Answer

Reduced risk of blood clotting

Answer

Atherosclerosis

Answer

Coronary heart disease

Question 2

In the hormonal regulation of lipogenesis, insulin and glucagon play distinct roles. Explain how insulin promotes lipogenesis and how glucagon inhibits it.

Accepted Answer

Insulin stimulates lipogenesis by promoting fatty acid synthesis, while glucagon inhibits lipogenesis by activating lipases.

Answer

Both insulin and glucagon stimulate lipogenesis.

Answer

Glucagon stimulates lipogenesis by promoting fatty acid synthesis, while insulin inhibits lipogenesis by activating lipases.

Answer

Neither insulin nor glucagon has any effect on lipogenesis.

Question 3

Identify the primary pathway responsible for degrading fatty acids in the body.

Accepted Answer

Beta-oxidation

Answer

Glycolysis

Answer

Lipogenesis

Answer

Cholesterol synthesis

Question 4

Which enzyme catalyzes the breakdown of triglycerides?

Accepted Answer

Lipase

Answer

Protease

Answer

Amylase

Answer

Sucrase

Question 5

Identify the key regulatory enzyme involved in lipogenesis.

Accepted Answer

Acetyl-CoA carboxylase

Answer

Pyruvate dehydrogenase

Answer

Citrate synthase

Answer

Glycerol kinase

Question 6

What serves as the precursor molecule for cholesterol synthesis?

Accepted Answer

Acetyl-CoA

Answer

Malonyl-CoA

Answer

Palmitate

Answer

Glucose

Question 7

Which type of lipid is essential for maintaining the integrity and functionality of cell membranes?

Accepted Answer

Phospholipids

Answer

Steroids

Answer

Triglycerides

Answer

Fatty acids

Question 8

Elevated levels of which lipoprotein are associated with an increased risk of cardiovascular disease?

Accepted Answer

Low-density lipoprotein (LDL)

Answer

High-density lipoprotein (HDL)

Answer

Very-low-density lipoprotein (VLDL)

Answer

Intermediate-density lipoprotein (IDL)

Question 9

In the liver, what is the primary metabolic fate of ketone bodies?

Accepted Answer

Utilization as an energy source

Answer

Conversion into glucose

Answer

Storage as glycogen

Answer

Excretion in urine

Question 10

What is the specific function of carnitine in the process of fatty acid oxidation?

Accepted Answer

Facilitating the transport of fatty acids across the mitochondrial membrane

Answer

Activating fatty acids

Answer

Generating ATP

Answer

Preventing beta-oxidation

Question 11

Familial hypercholesterolemia is a disorder that causes high cholesterol. Which of the following describes its usual presentation, inheritance pattern, and a common treatment?

Accepted Answer

Early heart disease, passed down directly from one parent, cholesterol-lowering medication

Answer

Type 2 diabetes, passed down only when both parents carry the gene, medication that binds to bile acids

Answer

High blood pressure, passed down on the X chromosome, vitamin B3 treatment

Question 12

Which enzyme is primarily responsible for initiating fatty acid synthesis?

Accepted Answer

Acetyl-CoA carboxylase

Answer

Fatty acid synthase

Answer

Malonyl-CoA decarboxylase

Answer

Enoyl-ACP reductase

Question 13

Which molecule is the substrate for cholesterol synthesis?

Accepted Answer

Mevalonate

Answer

Acetyl-CoA

Answer

Malonyl-CoA

Answer

Isopentenyl pyrophosphate

Question 14

What is the main function of carnitine in lipid metabolism?

Accepted Answer

Transport long-chain fatty acids into mitochondria

Answer

Catalyze fatty acid oxidation reactions

Answer

Regulate cholesterol biosynthesis

Answer

Activate fatty acids for lipogenesis

Question 15

Which hormone is responsible for stimulating fatty acid release from adipose tissue?

Accepted Answer

Epinephrine

Answer

Insulin

Answer

Glucagon

Answer

Prolactin

Question 16

What is a clinical consequence of elevated low-density lipoprotein (LDL) levels?

Accepted Answer

Increased risk of atherosclerosis

Answer

Reduced risk of coronary artery disease

Answer

Improved cardiovascular health

Answer

Enhanced cognitive function

Question 17

Which of the following conditions is a potential result of impaired lipid metabolism?

Accepted Answer

Hyperlipidemia

Answer

Hypoglycemia

Answer

Hemolytic anemia

Answer

Vitamin C deficiency

Question 18

Which enzyme is not directly involved in the beta-oxidation of fatty acids?

Accepted Answer

Lactate dehydrogenase

Answer

Carnitine palmitoyltransferase I

Answer

Acyl-CoA dehydrogenase

Answer

Enoyl-CoA hydratase

Question 19

Which enzyme is responsible for converting fatty acids into acetyl-CoA during fatty acid oxidation?

Accepted Answer

Acetyl-CoA synthetase

Answer

Lipase

Answer

Fatty acid synthase

Answer

Glucokinase

Question 20

A patient exhibits elevated triglycerides and diminished HDL cholesterol levels. Which disorder is most likely responsible for these abnormalities?

Accepted Answer

Metabolic syndrome

Answer

Type 1 diabetes

Answer

Familial hypercholesterolemia

Question 21

Which enzyme catalyzes the irreversible step in which fatty acids enter the mitochondria for oxidation?

Accepted Answer

Carnitine palmitoyltransferase I (CPT-I)

Answer

Acetyl-CoA synthetase

Answer

Lipoprotein lipase

Answer

Pyruvate dehydrogenase

Question 22

What is the primary role of carnitine in fatty acid oxidation?

Accepted Answer

Facilitates the transport of long-chain fatty acids across the inner mitochondrial membrane

Answer

Packages triglycerides for export from the liver

Answer

Converts fatty acids into acetyl-CoA

Answer

Breaks down triglycerides into free fatty acids and glycerol

Question 23

Which of the following is a characteristic of omega-3 fatty acids?

Accepted Answer

They are polyunsaturated fatty acids with at least one double bond on the third carbon from the methyl end

Answer

They are trans fatty acids

Answer

They are primarily found in animal products

Answer

They are saturated fatty acids

Question 24

What is the metabolic fate of acetoacetate, a ketone body produced in the liver?

Accepted Answer

It can be converted back to acetyl-CoA and used for energy in extrahepatic tissues like muscle and brain

Answer

It is converted into glucose through gluconeogenesis

Answer

It is stored as a reserve energy source in adipose tissue

Answer

It is excreted in the urine

Question 25

Which enzyme deficiency is associated with familial hypercholesterolemia, a genetic disorder characterized by elevated levels of LDL cholesterol?

Accepted Answer

LDLR (low-density lipoprotein receptor)

Answer

Cholesterol 7α-hydroxylase

Answer

Lecithin cholesterol acyltransferase

Answer

Lipoprotein lipase

Question 26

What is the primary function of phospholipids in cell biology?

Accepted Answer

Essential components of biological membranes, forming the lipid bilayer

Answer

Hormone precursors

Answer

Energy storage molecules

Answer

Vitamin transport molecules

Question 27

What is a potential clinical consequence of sustained elevated levels of triglycerides in the blood?

Accepted Answer

Increased risk of cardiovascular disease, including atherosclerosis and heart attack

Answer

Improved cognitive function

Answer

Enhanced immune response

Answer

Reduced risk of type 2 diabetes

Question 28

Which of the following is NOT considered a major class of lipids?

Accepted Answer

Polysaccharides

Answer

Cholesterol

Answer

Phospholipids

Answer

Triglycerides

Question 29

The primary organelle for fatty acid oxidation is the:

Accepted Answer

Mitochondria

Answer

Endoplasmic Reticulum

Answer

Nucleus

Answer

Cytoplasm

Question 30

Which enzyme initiates fatty acid synthesis?

Accepted Answer

Acetyl-CoA carboxylase

Answer

Fatty acid synthase

Answer

Lipase

Answer

Malate dehydrogenase

Question 31

The primary storage form of lipids in the body is:

Accepted Answer

Triglycerides

Answer

Phospholipids

Answer

Steroids

Answer

Cholesterol

Question 32

Which hormone is responsible for stimulating lipolysis?

Accepted Answer

Glucagon

Answer

Estrogen

Answer

Prolactin

Answer

Insulin

Question 33

The precursor molecule for cholesterol synthesis is:

Accepted Answer

Acetyl-CoA

Answer

Palmitic acid

Answer

Glycerol

Answer

Glucose

Question 34

Which of the following is a known risk factor for developing hypercholesterolemia?

Accepted Answer

Excessive saturated fat intake

Answer

Low smoking rate

Answer

High fiber diet

Answer

Regular exercise

Question 35

The process of converting excess glucose into triglycerides is known as:

Accepted Answer

De novo lipogenesis

Answer

Glycolysis

Answer

Gluconeogenesis

Question 36

Which of the following is NOT a function of phospholipids?

Accepted Answer

Energy storage

Answer

Emulsification

Answer

Membrane structure

Answer

Cell signaling

Question 37

The enzyme responsible for hydrolyzing triglycerides into fatty acids and glycerol is:

Accepted Answer

Lipase

Answer

Nuclease

Answer

Protease

Answer

Amylase

Question 38

Which of the following is the primary function of carnitine palmitoyltransferase I (CPT-I)?

Accepted Answer

To enable long-chain fatty acid entry into the mitochondrial matrix for oxidation

Answer

To activate fatty acids for oxidation

Answer

To synthesize ketone bodies

Question 39

Which enzyme is responsible for the first committed step of lipogenesis?

Accepted Answer

Acetyl-CoA carboxylase (ACC)

Answer

Fatty acid synthase (FAS)

Answer

Malonyl-CoA decarboxylase

Answer

Carnitine palmitoyltransferase II (CPT-II)

Question 40

Identify the final product of the cholesterol synthesis pathway:

Accepted Answer

7-Dehydrocholesterol

Answer

Isopentenyl pyrophosphate

Answer

Acetyl-CoA

Answer

Squalene

Question 41

What is the primary clinical consequence associated with elevated levels of low-density lipoprotein (LDL)?

Accepted Answer

Increased risk of cardiovascular disease

Answer

Hypertension

Answer

Obesity

Answer

Impaired glucose tolerance

Question 42

Identify the major regulatory enzyme involved in the ketogenesis pathway:

Accepted Answer

3-Hydroxy-3-methylglutaryl-CoA synthase (HMG-CoA synthase)

Answer

Acetyl-CoA carboxylase

Answer

Fatty acid synthase (FAS)

Answer

Carnitine palmitoyltransferase I (CPT-I)

Question 43

Which of the following is a major risk factor for developing non-alcoholic fatty liver disease (NAFLD)?

Accepted Answer

Obesity

Answer

Smoking

Answer

High blood pressure

Answer

Alcohol consumption