Enzymes and Digestion

Question 1

Name the muscular tube that carries food from mouth to stomach

Answer 1

oesophagus

Question 2

Which macromolecule is digested in the stomach?

Answer 2

protein

Question 3

State two functions of the ileum

Answer 3

digestion of food by enzymes

absprption of the products of digestion

Question 4

Where does the majority of the water absorbed by the large intestine originate?

Answer 4

secretionsof digestive glands

Question 5

Define egestion

Answer 5

process of removal of faeces from the rectum via the anus

Question 6

State two purposes of physical digestion

Answer 6

increase surface area for enzyme action

make food easier to swallow

Question 7

Describe hydrolysis

Answer 7

splitting fo molecules by adding water

Question 8

Describe the action of salivary amylase

Answer 8

hydrolyse starch into maltose

Question 9

Describe how the optimum neutral pH for amylase is maintained in the mouth

Answer 9

saliva contains mineral salts

Question 10

Explain why alkaline salts are produced by the pancreas and intestinal wall

Answer 10

to maintain a neutral pH for pancreatic amylase

Question 11

Give 3 examples of disaccharidases

Answer 11

maltalse
lactase
sucrase

Question 12

Explain what is meant by ‘membrane bound disaccharidase’

Answer 12

the disaccharide is bound to the wall of the intestine rather than being released into the intestine

Question 13

Describe the function of lipase

Answer 13

hydrolyse the ester bond in triglycerides to form monogylcerides and two fatty acids

Question 14

Describe emulsification

Answer 14

the splitting of large lipids into small droplets called micelles

Question 15

Describe the role of the liver in lipid digestion

Answer 15

produces bile salts that emulsify fat

Question 16

Explain why emulsification increases the rate of lipid digestion

Answer 16

increases the surface area for lipase action

Question 17

NAme the group of enzymes that hydrolyse proteins

Answer 17

peptidases

Question 18

Describe the function of endopeptidases

Answer 18

hydrolyse peptide bonds in the centre of a protein molecule forming smaller peptides

Question 19

Describe the function of exopeptidases

Answer 19

hydrolyse peptide bonds on the terminal amino acids of peptides to form dipeptides and single amino acids

Question 20

Describe the function of dipeptidases

Answer 20

hydrolyse dipeptidases into amino acids