2.5.9 Humans: Digestive Enzymes

Question 1

What is the purpose of digestion

Answer 1

to break down large, insoluble molecules into smaller, soluble molecules that can be absorbed into the bloodstream

Question 2

How is food digested

Answer 2

Food is partially digested mechanically (by chewing, churning and emulsification) in order to break large pieces of food into smaller pieces of food which increases the surface area for enzymes to work on

Question 3

How does digestion mainly take place?

Answer 3

Digestion mainly takes place chemically

• where bonds holding the large molecules together are broken to make smaller and smaller molecules

Question 4

Chemical digestion is controlled, what?

Answer 4

by enzymes which are produced in different areas of the digestive system

Question 5

What are enzymes

Answer 5

Enzymes are biological catalysts

– they speed up chemical reactions without themselves being used up or changed in the reaction

Question 6

There are 3 main types of digestive enzymes, what are they?

Answer 6

Carbohydrases, Protease, Lipases

Question 7

Carbohydrases are enzymes that break down carbohydrates into, what?

Answer 7

to simple sugars such as glucose

Question 8

What is amylase

Answer 8

Amylase is a carbohydrase which is made in the salivary glands, the pancreas and the small intestine

Question 9

Amylase breaks down starch into what?

Answer 9

maltose

Question 10

Maltase then breaks down maltose into

Answer 10

glucose

Question 11

Proteases are a group of enzymes that break down proteins into, what?

Answer 11

amino acids

Question 12

What is pepsin

Answer 12

Pepsin is an enzyme made in the stomach which breaks down proteins into smaller polypeptide chains

Question 13

Proteases made in the pancreas and small intestine break, what into amino acids?

Answer 13

break the peptides into amino acids

Question 14

What are Lipases

Answer 14

Lipases are enzymes that break down lipids (fats) to glycerol and fatty acids

Question 15

Where are lipase enzymes produced

Answer 15

Lipase enzymes are produced in the pancreas

Question 16

Where are lipase enzymes secreted

Answer 16

into the small intestine

Question 17

Exam Tip

Answer 17

The pancreas is an accessory organ in the digestive system. Food does not pass directly through it, but it has a key role in producing digestive enzymes as well as the hormones that regulate blood sugar (insulin and glucagon).