Protein And Starch Digestion

Question 1

Define digestion

Answer 1

The hydrolysis of large insoluble molecules by enzymes to produce smaller soluble molecules that can be absorbed and assimilated

Question 2

Describe digestion of glucose

Answer 2

• To enter microvilli glucose co transported with sodium ions ( diffusing) through carrier protein- no atp needed
• sodium potassium pump ensures a low concentration of sodium in the microvilli. Uses channel proteins and requires atp as sodium ions moving against conc gradient. Potassium ions are going through facilitated diffusion
• glucose diffuses into blood via facilitated diffusion

Question 3

What is starch hydrolysed by and where

Answer 3

Amylase hydrolyses it into maltose
Produced in salivary gland and pancreas
Works in mouth and small intestine

Question 4

What is maltose hydrolysed by

Answer 4

Maltase produced in small intestine membrane
Hydrolyses it into glucose

Question 5

What do endopeptidases hydrolyse

Answer 5

Internal peptide bonds to form several polypeptides

Question 6

What do exopeptidases hydrolyse

Answer 6

Terminal peptide bonds to form single amino acids

Question 7

How is the ileum adapted for the function of absorption (4/5marks)

Answer 7

Folded wall
Villi
Thin walls lined with epithelial cells
Rich supply of blood capillaries

Villi increase SA, which increase rate of diffusion
Have microvilli that further increases the SA