Digestion of carbohydrates

Question 1

Types of enzymes are important for the digestion

of carbohydrates

Answer 1

1. Amylases

2. Disaccharidases

Question 2

Disaccharidases function

Answer 2

Convert disaccharides to monosaccharides

Question 3

Amylases function

Answer 3

convert polysaccharides to disaccharides

Question 4

types of Amylases

Answer 4

1. Salivary Amylase

2. Pancreatic Amylase

Question 5

types of Disaccharidases

Answer 5

1. Maltase
2. Sucrase-Isomaltase
3. Lactase
4. Trehalase

Question 6

Digestion of Carbohydrate starts in

Answer 6

the mouth

Question 7

ptylin (salivary amylase) Location

Answer 7

mouth

Question 8

ptylin (salivary amylase) optimum pHمهم

Answer 8

6.7 (Range 6.6 to 6.8)

Question 9

ptylin (salivary amylase) action stops in

Answer 9

the stomach when the pH falls to 3.0.

Question 10

ptylin (salivary amylase) structure and function

Answer 10

1.α-amylase and requires Cl− ion for activation
2.hydrolyses α-1→ 4 glycosidic linkages
for both amylase

Question 11

Digestion in the Mouth Drawback

Answer 11

Shorter duration of food in mouth.
• Thus it is incomplete digestion of starch or
glycogen in the mouth.

Question 12

Digestion in the Stomach

Answer 12

HCl causes hydrolysis of sucrose to fructose and glucose.

no enzyme to break the glycosidic bonds

Question 13

Digestion in Duodenum

Answer 13

Pancreatic juice contains pancreatic amylase

amylopsin

Question 14

pancreatic amylase Optimum pH

Answer 14

7.1

Question 15

Only difference between salivary and pancreatic amylase

Answer 15

optimum pH
Salivary: 6.7
Pancreatic: 7.1

Question 16

Starch/Glycogen Starch, and dextrins is converted by salivary amylase

Answer 16

Maltose and Maltotriose

Question 17

Starch/Glycogen is converted by pancreatic amylase

Answer 17

Maltose/ Isomaltose +Dextrins and oligosaccharides

Question 18

Main digestion takes place in

Answer 18

the small intestine by pancreatic amylase. Digestion is completed by pancreatic amylase because food stays for a longer time in the
intestine

Question 19

Disaccharidases location

Answer 19

brush border epithelium of intestinal mucosal cells

Question 20

Maltose

Answer 20

Glucose + Glucose

Question 21

Sucrose Isomaltose

Answer 21

3Glucose + fructose

Question 22

Lactose

Answer 22

Glucose + Galactose

Question 23

Congenital Lactose intolerance

Answer 23

1. complete deficiency of lactase enzyme.
2. after birth.
3. diagnosed in early infancy
4. Milk feed precipitates symptoms

Question 24

Primary Lactase deficiency

Answer 24

during adulthood.
2.gene >RNA → no enzyme
intolerance to milk + dairy products.

Question 25

Secondary lactase deficiency

Answer 25

acute illness

Question 26

Sucrase-Isomaltase deficiency test

Answer 26

test is mucosal biopsy.

Question 27

Sucrase-Isomaltase deficiency h Benedict’s

test

Answer 27

Urine does not give +ve test because of sucrose(Non reducing sugar).

Question 28

Diagnosis of lactase deficiency

Answer 28

1. Hydrogen Breath Test

2. Stool Acidity Test

Question 29

Hydrogen Breath Test The person drinks a

Answer 29

lactoseloaded beverage

Question 30

Hydrogen Breath Test measure

Answer 30

the amount of hydrogen (undigested lactose produces high levels of hydrogen)

Question 31

Hydrogen Breath Test takes

Answer 31

2 to 3 hours

Question 32

Stool Acidity Test measure

Answer 32

the amount of acid in the stool. حاية من
lactic acid
short chain fatty acids
lactose

Question 33

Benedict’s test, lactose deficiency

Answer 33

Mucosal biopsy

urine showspositive test → lactose reducing sugar