Section 7 - Orange

Question 1

By what process does food move through the alimentary canal?

Answer 1

Peristalsis

Question 2

Define the term peristalsis

Answer 2

Wave-like, rhythmic muscular contractions that squeeze food through the digestive tract

Question 3

Describe the process of chemical digestion in the mouth

Answer 3

Amylase released from salivary gland to digest starch into maltose

Question 4

Describe the process of physical digestion in the mouth

Answer 4

Mechanical digestion by teeth to break food into smaller pieces.
(increases surface area to volume ratio)

Question 5

How does chewing food help to speed up digestion?

Answer 5

Increase surface area for enzymes to act on

Question 6

Describe the process of physical digestion in the stomach

Answer 6

Mechanical digestion as muscular stomach wall pummels and churns food.

Question 7

Describe the process of chemical digestion in the stomach

Answer 7

Low pH (pH2 caused by hydrochloric acid) provides optimum conditions for pepsin (a type of protease) which digests proteins into amino acids.

Question 8

Where is bile produced and then stored?

Answer 8

Produced in liver, stored in gall bladder.

Question 9

Describe the roles of bile

Answer 9

Neutralises stomach acid; emulsifies fats into smaller droplets so as to increase the surface area for digestion by lipase enzyme.

Question 10

Why is it important that bile neutralises stomach acid?

Answer 10

Neutralises stomach acid so as not to denature digestive enzymes in the small intestine