Enzymes and Digestion

Question 1

What is the oesophagus?

Answer 1

Carries food from the mouth to the stomach.

Question 2

What is the stomach?

Answer 2

Muscular sac with an inner layer producing enzymes. It has glands that produce enzymes which digest protein.

Question 3

What is the role of the stomach?

Answer 3

Store and digest food, especially proteins.

Question 4

What is the ileum (small intestine)?

Answer 4

Long muscular tube where food is further digested by enzymes produced by its walls and glands.

Question 5

What is the structure of the ileum and how does it aid absorption and digestion?

Answer 5

Inner walls of ileum are folded into villi, increasing their surface area, which is then further increased by microvilli on the epithelial cells of each villus.

Question 6

What is the large intestine?

Answer 6

Absorbs water, mainly the water from the secretion of the many digestion glands.

Question 7

What is the rectum?

Answer 7

Final section of intestines. The faeces are stored here before periodically being removed via the anus in a process known as egestion.

Question 8

What are the salivary glands?

Answer 8

Situated near the mouth. They pass their secretions via a duct into the mouth.

Question 9

What do the salivary gland secretions contain?

Answer 9

The enzyme amylase, which hydrolyses starch into maltose.

Question 10

What is the pancreas?

Answer 10

Large gland situated below the stomach. Produces a secretion called pancreatic juice.

Question 11

What does the pancreas secretions contain?

Answer 11

Proteases which hydrolyse proteins, lipase to hydrolyse lipids, and amylase to hydrolyse starch.

Question 12

What are the two stages of digestion?

Answer 12

• physical breakdown

- chemical digestion

Question 13

What is the process of physical breakdown?

Answer 13

Large food is broken down into smaller pieces by the teeth. Makes it possible to ingest food and creates a large surface area for chemical digestion. Food is churned in muscles of stomach, also physically breaks it up.

Question 14

What is the process of chemical digestion?

Answer 14

Hydrolyses large, insoluble molecules into smaller soluble ones. Carried out by enzymes that function by hydrolysing molecules by adding water to it.

Question 15

What are the three main digestive enzymes that contribute to chemical digestion of food?

Answer 15

Carbohydrases, lipases, proteases.

Question 16

What are carbohydrases?

Answer 16

Hydrolyse carbohydrates, to monosaccharides.

Question 17

What are lipases?

Answer 17

Hydrolyse lipids into glycerol and fatty acids.

Question 18

What are proteases?

Answer 18

Hydrolyse proteins to amino acids.