Carbohydrates

Question 1

What are the 3 important monosaccharides in human biochemistry?

Answer 1

Glucose, galactose and fructose

Question 2

What are the 3 important disaccharides in human biochemistry?

Answer 2

Maltose, lactose and sucrose

Question 3

Is maltose a reducing sugar?

Answer 3

Yes

Question 4

What is the main sugar in milk?

Answer 4

Lactose

Question 5

Is lactose a reducing sugar?

Answer 5

Yes

Question 6

Which monosaccharides make up lactose?

Answer 6

Galactose and glucose

Question 7

Which monosaccharides make up maltose?

Answer 7

2x glucose

Question 8

Which monosaccharides make up sucrose?

Answer 8

Fructose and glucose

Question 9

Is sucrose a reducing sugar?

Answer 9

No

Question 10

What distinguishes homopolysaccharides from heteropolysaccharides?

Answer 10

Homopolysaccharides - single monomeric species

Heteropolysaccharides - two or more monomer species

Question 11

Which two types of glucose polymer make up starch?

Answer 11

Amylose and amylopectin

Question 12

What is the main difference between amylose and amylopectin?

Answer 12

Amylose is linear but amylopectin is branched

Question 13

What is the difference between starch and glycogen?

Answer 13

Glycogen is more extensively branched than starch

Question 14

What are glycoproteins?

Answer 14

Proteins that have carbohydrates covalently attached

Question 15

What are mucopolysaccharidoses?

Answer 15

A group of genetic disorders caused by the absence or malfunction of enzymes that are required for the breakdown of glycosaminoglycans

Question 16

What happens in the mouth to aid carbohydrate digestion?

Answer 16

Salivary amylase hydrolyses (α1→4) bonds of starch

Question 17

What happens in the stomach to aid carbohydrate digestion?

Answer 17

Nothing

Question 18

What happens in the duodenum to aid carbohydrate digestion?

Answer 18

Pancreatic amylase hydrolyses (α1→4) bonds of starch

Question 19

What are the 4 enzymes that act in the jejunum to digest carbohydrates?

Answer 19

Isomaltase, glucoamylase, sucrase, lactase

Question 20

What is the most common disaccharidase deficiency?

Answer 20

Lactose intolerance

Question 21

Which enzyme catalyses the phosphorylation of glucose into glucose 6-phosphate in the liver once it enters the cell?

Answer 21

Glucokinase

Question 22

Which enzyme catalyses the phosphorylation of glucose into glucose 6-phosphate once it enters the cell, except in the liver?

Answer 22

Hexokinase

Question 23

Why does glucose 6-phosphate not diffuse out of the cell?

Answer 23

The GLUT transporter will not recognise it

Question 24

Does glucokinase have a high or low Km for glucose?

Answer 24

High

Question 25

Does glucokinase have a high or low Vmax?

Answer 25

High

Question 26

Does hexokinase have a high or low Km for glucose?

Answer 26

Low

Question 27

Does hexokinase have a high or low Vmax?

Answer 27

Low

Question 28

Does glycogen form directly from glucose monomers?

Answer 28

No