Enzymes and Digestion

Question 1

What do digestive enzymes break down?

Answer 1

Big molecules.

Question 2

What molecules do digestive enzymes break down?

Answer 2

Starch, proteins and fats. They’re too big to pass through the walls of the digestive system, so digestive enzymes break these big molecules down into smaller ones like sugars, amino acids, glycerol and fatty acids. These smaller, soluble molecules can pass easily through the walls of the digestive system, allowing them to be absorbed into the bloodstream.

Question 3

Example of a carbohydrase and what does it do?

Answer 3

Amylase. It breaks down starch (carbohydrate) into maltose and other sugars. Made in the 1. Salivary glands 2. The pancreas 3. The small intestine.

Question 4

What do proteases do?

Answer 4

Convert Proteins into amino acids. Made in 1. The stomach (pepsin) 2. The pancreas 3. The small intestine.

Question 5

What do lipases do?

Answer 5

Convert Lipids (fats and oils) into Glycerol and Fatty Acids. Made in 1. The pancreas 2. The small intestine.

Question 6

What does the body do with the products of digestion?

Answer 6

They are used to make new carbohydrates, proteins and lipids. Some of the glucose (carbohydrate) that’s made is used in respiration.

Question 7

What and where is bile?

Answer 7

1. A fluid that is produced in the liver. 2. It’s stored in the gall bladder before it’s released into the small intestine.

Question 8

What does bile help with?

Answer 8

1. The hydrochloric acid in the stomach makes the pH too acidic for enzymes in the small intestine to work properly. Bile is alkaline - it neutralises the acid and makes conditions alkaline. The enzymes in the small intestine work best in these alkaline conditions.
2. It emulsifies fats. It breaks the fat into tiny droplets. This gives a much bigger surface area of fat for the enzyme lipase to work on - which makes its digestion faster.