Question 1

Which of the following best describes the process of gluconeogenesis in humans?

Accepted Answer

The synthesis of glucose from non-carbohydrate precursors such as amino acids and glycerol.

Question 2

A patient with type 2 diabetes is advised to increase their intake of dietary fibre. Which of the following best explains the protective role of fibre in this context?

Accepted Answer

Fibre slows gastric emptying and glucose absorption, helping to regulate postprandial blood glucose.

Question 3

Which of the following equations correctly represents the general formula for a carbohydrate?

Accepted Answer

$$\mathrm{C}_n\mathrm{H}_{2n}\mathrm{O}_n$$

Question 4

A person consumes a meal high in triglycerides. Which sequence best describes the metabolic fate of these lipids?

Accepted Answer

Digestion by lipases and bile → absorption → beta-oxidation → ATP production

Question 5

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

Accepted Answer

They include omega-3 and omega-6 fatty acids, which must be obtained from the diet.

Question 6

A patient with marasmus is most likely to present with which of the following clinical features?

Accepted Answer

Severe wasting of muscle and fat due to overall energy deficiency.

Question 7

Which of the following best distinguishes between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids contain only single bonds between carbon atoms, while unsaturated fatty acids contain one or more double bonds.

Question 8

Which of the following is a correct sequence for the digestion and absorption of dietary proteins?

Accepted Answer

Digestion by pepsin and pancreatic proteases → absorption as amino acids → protein synthesis

Question 9

A person with phenylketonuria (PKU) must avoid foods high in phenylalanine. Which metabolic pathway is impaired in this condition?

Accepted Answer

Conversion of phenylalanine to tyrosine due to a deficiency of phenylalanine hydroxylase.

Question 10

Which of the following best explains why cellulose is considered dietary fibre and not a source of energy for humans?

Accepted Answer

Cellulose is a polysaccharide that cannot be digested by human enzymes due to its beta-1,4 glycosidic bonds.

Question 11

A patient with chronic kidney disease (CKD) is advised to limit protein intake. Which of the following best explains the rationale?

Accepted Answer

High protein intake increases urea production, which the impaired kidneys cannot efficiently excrete.

Question 12

Which of the following lipoproteins is primarily responsible for transporting dietary triglycerides from the intestine to peripheral tissues?

Accepted Answer

Chylomicrons

Question 13

Which of the following best describes the process of beta-oxidation?

Accepted Answer

The breakdown of fatty acids in the mitochondria to generate acetyl-CoA for ATP production.

Question 14

A person consumes a meal containing 60 g of carbohydrate, 20 g of protein, and 10 g of fat. Using the Atwater factors ($$4$$ kcal/g for carbohydrate and protein, $$9$$ kcal/g for fat), what is the total energy content of the meal?

Accepted Answer

$$(60 	imes 4) + (20 	imes 4) + (10 	imes 9) = 240 + 80 + 90 = 410$$ kcal

Question 15

Which of the following best explains why trans fats are associated with increased cardiovascular disease risk?

Accepted Answer

Trans fats increase LDL cholesterol and decrease HDL cholesterol, promoting atherosclerosis.

Question 16

Which of the following is a correct description of the urea cycle?

Accepted Answer

A metabolic pathway in the liver that converts toxic ammonia from amino acid catabolism into urea for excretion.

Question 17

Which of the following best explains the difference between complete and incomplete proteins?

Accepted Answer

Complete proteins contain all essential amino acids in adequate proportions; incomplete proteins lack one or more essential amino acids.

Question 18

A person with coeliac disease must avoid gluten-containing foods. Which of the following best describes the underlying issue?

Accepted Answer

An immune-mediated reaction to gluten leads to damage of the small intestinal mucosa.

Question 19

Which of the following best describes the role of phospholipids in the body?

Accepted Answer

They are major components of cell membranes, forming a bilayer that regulates transport.

Carbohydrates, Lipids, and Proteins: Structure, Metabolism, and Health Implications

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