Digestive system and enzymes

Question 1

What happens to food in the mouth.

Answer 1

Teeth chew food. Tongue forms a bolus (ball) of food. Saliva contains amylase which is an enzyme that breaks down starch.

Question 2

What does the oesophagus do?

Answer 2

Muscles contract to push food down to the stomach. This is called peristalsis.

Question 3

What happens in the stomach?

Answer 3

Muscles contract to churn food. Stomach acid kills bacteria and makes it a low pH for pepsin to work (enzyme that breaks down protein).

Question 4

What happens in the small intestine?

Answer 4

Digests large food molecules into smaller soluble molecules that are then absorbed into the bloodstream.

Question 5

What happens in the large intestine?

Answer 5

Water is absorbed.

Question 6

What does the pancreas do?

Answer 6

Releases enzymes into the small intestine.

Question 7

What does the liver do?

Answer 7

Makes bile which is used to break down fats.

Question 8

What does the gall bladder do?

Answer 8

Stores bile.

Question 9

Describe the adaptations of villi.

Answer 9

They have a very large surface area to absorb more nutrients. They have very thin walls (1 cell thick) so they are absorbed quickly. They have a large network of capillaries for quicker diffusion.

Question 10

What are enzymes?

Answer 10

Biological catalysts - things that speed up reactions.