Digestion & Enzymes · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Digestion and Enzymes

Science · Organisms & Life Processes · ages 11-13
Name ______________________   Date ____________

  1. In a lab, scientists add an enzyme to a beaker of starch. The starch turns into sugar much faster than it would on its own. What did the enzyme do?

    • It tore the starch into smaller pieces
    • It sped up the chemical reaction
    • It swallowed the starch like a living thing

  2. Look at the digestion sequence. Which organ comes right after the highlighted one?

    MouthOesophagusStomachSm.IntestineLg.Intestine
    • Small intestine
    • Oesophagus
    • Large intestine (colon)

  3. Chewing food with your teeth is an example of chemical digestion.

    Circle one:   True   False

  4. Ravi's stomach churns his food and also mixes it with an enzyme that breaks down protein. Which part is chemical digestion?

    • The enzyme part
    • The muscles churning the food
    • Both are the same process

  5. Which gland produces the enzyme that starts breaking down starch, before food is even swallowed?

    • Stomach
    • Large intestine and stomach
    • Salivary glands

  6. Which organ absorbs most of the nutrients after enzymes have broken food down into small molecules?

    • Oesophagus
    • Small intestine
    • Mouth and teeth

  7. If someone's small intestine made none of its own enzymes but still received enzymes from the pancreas, what would most likely happen to their digestion?

    • Less food would be ready to be absorbed
    • Food would be chewed less thoroughly
    • Food would move through faster than normal

  8. Lina says: 'Enzymes are living things that swim through your gut and eat food particles.' What is wrong with her statement?

    • Enzymes are made only in the stomach
    • Enzymes cannot break down protein
    • Enzymes are proteins
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Digestion and Enzymes W1-mt_0NlbulkB5P-s1

  1. It sped up the chemical reaction · Enzymes are proteins that speed up chemical reactions, which is what happened in the beaker.
  2. Small intestine · Food travels stomach, then small intestine, then large intestine.
  3. False · Chewing changes the size and shape of food, so it is physical digestion.
  4. The enzyme part · An enzyme changing food's molecules is chemical digestion; churning is physical digestion.
  5. Salivary glands · Salivary glands release amylase into the mouth; the stomach and small intestine make their own enzymes later in digestion.
  6. Small intestine · The small intestine absorbs nutrients once enzymes finish breaking food into small molecules.
  7. Less food would be ready to be absorbed · The pancreas would still send enzymes, so some breakdown would carry on. Without its own enzymes, the final breakdown would be less full, so less food would be ready to be absorbed.
  8. Enzymes are proteins · Enzymes are proteins that speed up chemical reactions. They are not living things that swim around.
Worksheet · LightMySky