Carbohydrates

Question 1

What are the three types of carbohydrates called?

Answer 1

Monosaccharides, disaccharides, polysaccharides

Question 2

What is the main function of monosaccharides?

Answer 2

To store energy within their bonds. When bonds are broken during respiration, energy is released.

Question 3

Is glucose soluble or insoluble?

Answer 3

Soluble

Question 4

What reaction do monosaccharides undergo to form larger carbohydrates?

Answer 4

Condensation reactions.

Question 5

Are polysaccharides soluble or insoluble?

Answer 5

Insoluble

Question 6

How are disaccharides and polysaccharides formed?

Answer 6

When 2 OH groups on different monosaccharides interact to form a strong covalent bond (glycosidic bond)

Question 7

What does the reaction of a glycosidic bond also release?

Answer 7

A water molecule

Question 8

Glucose + glucose

Answer 8

Maltose

Question 9

Glucose + fructose

Answer 9

Sucrose

Question 10

Glucose + galactose

Answer 10

Lactose

Question 11

How is a glycosidic bond broken?

Answer 11

When water is added in a hydrolysis reaction

Question 12

What’s the glycosidic bond in maltose?

Answer 12

1,4

Question 13

What’s the glycosidic bond in sucrose?

Answer 13

1,2

Question 14

What’s the glycosidic bond in lactose?

Answer 14

1,4

Question 15

How do disaccharides release energy quick?

Answer 15

They are made up of two sugar molecules so they are easily broken down by enzymes in the digestive system to their monosaccharides and then absorbed into the bloodstream.

Question 16

Why are disaccharides easily soluble in water?

Answer 16

Due to the presence of many hydroxyl groups. The hydroxyl groups form hydrogen bonds with the water molecules when dissolved in aqueous solutions.

Question 17

What are 3 examples of polysaccharides?

Answer 17

Starch, glycogen, cellulose

Question 18

What does it mean if a polysaccharides is branched?

Answer 18

This means that it increases the rate at which the polysaccharide can be broken down

Question 19

Suitability of straight and coiled polysaccharides?

Answer 19

Straight- makes the molecules suitable for constructing cellular structures
Coiled- makes the molecules suitable for storage and more compact.

Question 20

Why are starch and glycogen useful as storage polysaccharides?

Answer 20

They are compact- so large quantities can be stored
They are insoluble- so they have no osmotic effect

Question 21

What is starch made up of, and explain

Answer 21

Amylose- unbranched helix shaped chain with 1,4 glycosidic bonds between alpha glucose molecules
Amylopectin- branched molecule containing 1,4 glycosidic bonds between alpha glucose molecules and 1,6 glycosidic bonds.

Question 22

What is the benefit of of the branches of amylopectin?

Answer 22

The branches result in many terminal glucose molecules that can easily be hydrolysed for use during respiration or for storage.

Question 23

Features of glycogen?

Answer 23

It is highly branched and not coiled. It contains both 1,4 and 1,6 glycosidic bonds/

Question 24

What is the benefit of glucose being even more branched than amylopectin?

Answer 24

The branching provides more terminal glucose molecules which can either be added or removed by hydrolysis. This allows the quick storage or release of glucose to suit the demands of the cell

Question 25

What is the benefit of glycogen being compact?

Answer 25

This means that much can be stored in a small space.