Enzymes and digestion

Question 1

What are the parts of the digestive system?

Answer 1

1 - Salivary gland
2 - Oesophagus
3 - Stomach 
4 - Small intestine/ileum
5 - Pancreas
6 - Large intestine
7 - Rectum

Question 2

What is the role of the salivary gland in the digestive system?

Answer 2

Salivary Gland - Located near the mouth, there are 3 pairs of them. It contains amylase which secretes into the mouth to break down starch by hydrolysis into maltose.

Question 3

What is the role of the oesophagus in the digestive system?

Answer 3

Oesophagus - Thick muscular tube and has squamous epithelium, it carries food from the mouth to the stomach by contracting the muscle and pushing it down.

Question 4

What is the role of the stomach in the digestive system?

Answer 4

Stomach - Muscular sac for contraction so it churns the food and it has an inner layer that produces enzymes. It secretes HCL acid to kill bacteria and enzyme pepsin to digest food - especially proteins.

Question 5

What is the role of the small intestine/ileum in the digestive system?

Answer 5

Small intestine/ileum - Long muscular tube with folded epithelium made of microvilli which provides a large SA. Cells in the lumen of the ileum secrete enzyme which allows further digestion of food. Those adaptations allow the ileum to absorb the products of digestion into the bloodstream.

Question 6

What is the role of the pancreas in the digestive system?

Answer 6

Pancreas - 95% made up of exocrine tissue. It’s a large gland below the stomach. It secretes pancreatic juice which contains proteases to hydrolyse proteins, lipase to hydrolyse lipids and amylase to hydrolyse starch.

Question 7

What is the role of the large intestine in the digestive system?

Answer 7

Absorb water, most water is the water from the secretion of many digestive glands.

Question 8

What is the role of the rectum in the digestive system?

Answer 8

Faeces are stored here before it’s been removed by the anus in a process called egestion.

Question 9

What are the 2 stages of digestion?

Answer 9

Physical breakdown.

Chemical breakdown.

Question 10

What is a physical breakdown?

Answer 10

Food is broken down from large to small pieces by structures e.g. teeth.
It makes it easier to ingest the food but also provides a large SA for the chemical breakdown.

Question 11

What is a chemical breakdown?

Answer 11

It hydrolyses large insoluble molecules into smaller soluble ones by the work of enzymes.

Question 12

What are the 3 main digestive enzymes?

Answer 12

1) Carbohydrase - hydrolyse carbohydrates into monosaccharides.
2) Lipase - hydrolyse lipids into glycerol and fatty acids.
3) Proteases - hydrolyse proteins into amino acids.