5. Nutrition in humans (Digestion)

In which parts of the digestive system do amylase act on?

• mouth and pancreas

• mouth and small intestine

• mouth, pancreas, and small intestine

• mouth, stomach, pancreas, small intestine

Proteins are digested into polypeptides by pepsin. According to the 'lock and key' hypothesis, which identifies the 'lock' and 'key' in this reaction correctly?

• lock: pepsin

  key: polypeptides

• lock: pepsin

  key: protein

• lock: polypeptides

  key: protein

• lock: protein

  key: pepsin

which of the following events does NOT occur in small intestine?

• activation of pepsinogen to pepsin

• enzymes from the pancreas are added

• fats are emulsified

• maltose is digested

What is the function of the gall bladder?

• produces bile

• stores bile

• produces digestive enzymes

• stores digestive enzymes

A piece of bread that is chewed in the mouth gradually tastes sweeter. What is the explanation for this phenomenon?

• Saliva contains enzymes that break down starch in bread to glucose

• saliva releases simple sugars from bread

• starch is converted to maltose by salivary amylase

• the mouth secretes saliva that is sweet

The gall bladder of a man was surgically removed. Which of the activities below would he NOT be able to do?

1. Digest fats

2. Produce bile

3. synthesise fats

• 1 and 2

• 2 and 3

• 1, 2, and 3

• none of the above

Four test tubes containing oil and secretions from different parts of the alimentary canal are incubated for four hours at 37oC as shown below.

After 4 hours, the contents of the test tubes are subjected to ethanol-emulsion test. which row correctly shows the observations of the ethanol-emulsion test?

• A

• B

• C

• D

Lipase digests fats into...? (Select more than 1 below)

• Fatty acids

• Glycerol

• Glucose

• Glycogen

Maltase digest maltose into...?

• Maltose

• Glucose

• Glycogen

• Gl

What is the enzyme found in the stomach?

• Amylase

• lipase

• Pepsin