2 - Digestion

Question 1

Adaptations of Ilium

Answer 1

Villi

Thin walls

Presence of channel and carrier proteins for facilitated diffusion

Good blood supply to maintain a concentration gradient

Question 2

Parts of small intestine

Answer 2

Duodenum
Jejunum
Ileum

Question 3

Protein Digestion

Answer 3

Hydrolysed by enzymes called peptidases

Endopeptidase
-Break down peptide bonds between amino acids in the middle of a polypeptide chain

Exopeptidase
-Break down peptide bonds between amino acids at the end of a polypeptide chain

Membrane-bound dipeptidase
-Break down peptide bonds between last two amino acids left

Question 4

Lipid Digestion

Answer 4

1) Emulsification: Lipids split into tiny droplets called micelles by bile salts

2) Lipids hydrolysed by lipases which hydrolyse ester bonds in triglycerides to form fatty acids and monoglycerides

Question 5

Carbohydrate digestion

Answer 5

Amylase breaks down starch into maltose

Membrane-bound disaccharidases:

1) Maltase hydrolyses maltose into two glucose molecules.

2) Sucrase hydrolyses sucrose into glucose and fructose.

3) Lactase hydrolyses lactose into glucose and galactose.

Question 6

Co-transport with sodium ions

Answer 6

Used to absorb amino acids and monosaccharides

Sodium ions are actively transported out of the epithelial cell, creating a sodium ion gradient

Question 7

Digestion Definition

Answer 7

process in which large molecules are hydrolysed by enzymes to produce smaller molecules