K325 / 2027

Nutrition in humans

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Glucose enters a liver cell and is converted into glycogen. Which process does this illustrate?

  1. Absorption, because glucose has moved from the blood into a liver cell to be stored.
  2. Egestion, because a large molecule is formed.
  3. Assimilation, because an absorbed nutrient is made into a body substance.
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Assimilation, because an absorbed nutrient is made into a body substance.

The liver uses glucose to synthesise glycogen for storage.

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What best explains forward movement during peristalsis?

  1. A travelling contraction narrows the canal behind the food while the region ahead relaxes.
  2. Digestive enzymes break the food into small pieces that slide down towards the stomach by gravity.
  3. The whole canal remains tightly contracted at the same time.
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A travelling contraction narrows the canal behind the food while the region ahead relaxes.

The coordinated wave pushes the contents forwards rather than simply squeezing the whole tube shut at once.

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Which sequence correctly describes starch digestion?

  1. Lipase turns starch into amino acids.
  2. Amylase makes maltose, then maltase makes glucose.
  3. Bile emulsifies starch, then pancreatic lipase breaks it into glucose.
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Amylase makes maltose, then maltase makes glucose.

Identify both substrates and products: starch to maltose, then maltose to glucose.

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Which row correctly gives an enzyme, where it acts and its product?

  1. Lipase, mouth, glycerol and amino acids
  2. Protease, stomach, polypeptides
  3. Amylase, stomach, maltose
  4. Maltase, small intestine, starch
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Protease, stomach, polypeptides

Pepsin, a protease, begins protein digestion in the stomach, producing shorter polypeptides.

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Which structure-function pairing is correct?

  1. Lacteals carry all absorbed glucose directly to the liver.
  2. A thick epithelium increases the speed of nutrient crossing.
  3. Many villi give a large surface area for absorption.
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Many villi give a large surface area for absorption.

State the feature, its immediate effect and the resulting benefit to absorption.

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Which feature of a villus most directly speeds up the absorption of glucose into the blood?

  1. A lacteal that carries glucose straight to the liver
  2. Muscle in the villus that pumps glucose into the gut
  3. A thick wall many cells deep that protects the blood
  4. A dense network of capillaries that keeps the gradient steep
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A dense network of capillaries that keeps the gradient steep

Blood carries absorbed glucose away, keeping its concentration low beside the villus.

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Which route correctly traces absorbed glucose?

  1. Villus lacteal, lymph vessels, then the bile duct into the liver.
  2. Pancreas, gallbladder, stomach.
  3. Villus blood capillaries, hepatic portal vein, liver.
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Villus blood capillaries, hepatic portal vein, liver.

This carries blood rich in absorbed nutrients to the liver for processing.

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Which statement correctly distinguishes liver and kidney functions?

  1. The kidney makes bile and the liver stores urine.
  2. The liver forms urea; the kidneys remove it from blood into urine.
  3. The liver stores excess amino acids as protein; the kidneys turn them into urea.
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The liver forms urea; the kidneys remove it from blood into urine.

Formation and excretion occur in different organs, connected by transport in blood.

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A person eats far more protein than they need. What happens to the excess amino acids?

  1. They are egested in faeces because the body cannot use them
  2. The liver deaminates them and turns the nitrogen into urea
  3. The kidneys turn them into urea before they reach the liver
  4. The liver stores them in its cells as glycogen for later use
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The liver deaminates them and turns the nitrogen into urea

The amino group is removed and made into urea, which the kidneys excrete.

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Which chain correctly links a brain effect of alcohol to a possible social consequence?

  1. Reduced judgement can lead to risky decisions that injure other people.
  2. The liver breaks down alcohol, so no harm can occur.
  3. Alcohol speeds up reaction time, so a driver brakes sooner and has fewer collisions.
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Reduced judgement can lead to risky decisions that injure other people.

This links a biological effect to a possible behavioural and social consequence without claiming that the same outcome always occurs.

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Write a short answer, then compare it with a sample and check for missing ideas.

Question 1 of 8

Follow food and secretions

5 marks

Trace food from mouth to anus, naming the duodenum and ileum. Explain the roles of salivary glands, pancreas, liver and gallbladder without placing them in the route taken by food. Distinguish absorption from assimilation. [5]

Separate the canal, its supporting organs and the use of absorbed nutrients.

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