Carbohydrates

Question 1

What are carbohydrates made out of ?

Answer 1

Carbon , hydrogen , oxygen

Question 2

What is a monosaccharide and give 3 examples of them.

Answer 2

A monosaccharide is a single sugar unit . Example of them are glucose , fructose, galactose

Question 3

What is a monosaccharide and state the 3

Answer 3

A monosaccharide is a single sugar unit and they are glucose, fructose and galactose

Question 4

What is a disaccharide and state the 3:

Answer 4

2 monosaccharides link together to form a disaccharide. These are lactose , Sucrose and maltose

Question 5

Which monosaccharides join together to form maltose

Answer 5

2 alpha glucose molecules

Question 6

Which monosaccharides join together to form sucrose

Answer 6

Fructose and alpha glucose

Question 7

Which monosaccharides join together to form lactose

Answer 7

Galactose and alpha glucose

Question 8

What is the difference been Alpha glucose and Beta glucose?

Answer 8

Alpha glucose has its hydroxyl group below the first carbon link whereas Beta glucose has its hydroxyl group above the first carbon link

Question 9

What are the 3 uses of glucose

Answer 9

Structure, storage and energy

Question 10

Why is glucose soluable in water?

Answer 10

This is due to the hydrogen bonds that form between the hydroxyl groups and water molecules. Glucose is also polar. This is important as it can dissolve in a cell

Question 11

What is the purpose of starch

Answer 11

Storage of extra glucose in plants. It’s made of alpha glucose . It is insoluble so it doesn’t affect the water potential of a plant.

Question 12

Describe the structure of starch

Answer 12

Starch is a polysaccharide It contains the polysaccharide amylose which is made up of 1-4 glycosidic bonds which is angled allowing the chain to coil into a helix making it more compact . It is stabilised by hydrogen bonds. Starch also contains the polysaccharide amylopectin which has a 1-4 and1-6 glycosidic bond allowing for branching. This allows for a quick release of energy.

Question 13

What is the purpose of glycogen

Answer 13

Storage of extra glucose in animals

Question 14

Describe the structure of glycogen

Answer 14

It has the same structure as amylopectin however with more branching which speeds up the process of storing and releasing glucose .Its more compact meaning less space is needed for it to be stored and more can be stored which is important animals are mobile .

Question 15

What is the purpose of cellulose

Answer 15

It provides structural support in the cell wall of plants and is insoluable

Question 16

Describe the structure of cellulose

Answer 16

It is made of monosaccharides of Beta glucose which are inverted to join up the hydroxyl groups on carbon 1 and carbon 4 ( 1-4 glycosidic bond).
Cellulose is strong due to the many hydrogen bonds created that form a cellulose fibre

Question 17

Describe the formation of a glycosidic bond

Answer 17

A glycosidic bond is formed by a condensation reaction which is the joining together of 2 facing hydroxyl groups from 2 monomers/polymers leaving a by product of water.

Question 18

Explain what hydrolysis is

Answer 18

Hydrolysis is the breaking down of polymers into monomers. It breaks down the covenant bonds using water