MBS 217 Lecture 6

Question 1

2 steps of Carbohydrate digestion and
absorption

Answer 1

carbohydrases produced by the salivary glands and pancreas

brush border

Question 2

Carbohydrates: Salivary and Pancreatic
enzymes

Answer 2

Enzymes: salivary amylase & pancreatic alpha amylase

Question 3

pH of the enzymes

Answer 3

6.7 - 7.5

Question 4

When does saliva begin

Answer 4

Begins in mouth during mastication mixed with salivary amylase (parotid and submandibular salivary gland)

Question 5

What does starches break down into

Answer 5

Breaks down starches (complex carbohydrates) into disaccharides (2 simples sugars)

Question 6

How long does salivary amylase continue?

Answer 6

Salivary amylase continues (1-2h) until stomach acids renders the enzyme inactive

Question 7

Explain the Pancreatic phase

Answer 7

Duodenum: remaining carbohydrates – by pancreatic alpha amylase.

No disaccharides, tri-saccharides produced through digestion or any in the food is further digested.

Question 8

Duodenal phase – brush border

Answer 8

Disaccharides and tri-saccharides broken down into mono-saccharides by the brush border enzymes of the intestinal microvilli

Enzyme: Maltase: split bond between 2 glucose molecules of Maltose

Sucrase: breaks sucrose into glucose and fructose

Lactase: Breaks Lactose – glucose and galactose

Question 9

Explain Lactose Intolerant

Answer 9

Intestinal mucosa stops producing lactase

Question 10

Absorption of Monosaccharides

Answer 10

Intestinal epithelium
 Diffusion (Passive or facilitated)
 Co-transport

Question 11

Carbohydrates

Answer 11

Consist of starches, glycogen, sucrose, lactose,
glucose, fructose
 Polysaccharides broken down to monosaccharides
 Monosaccharides taken up by active transport or
facilitated diffusion and carried to liver
 Glucose is transported to cells requiring energy
 Insulin influences rate of transport