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AQA Biology AS level H > Polysaccharides > Flashcards

Flashcards in Polysaccharides Deck (22)
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1

What are polysaccharides?

Carbohydrates

2

What are polysaccharide molecules made from?

Large numbers of their monomers

3

How is a polysaccharide formed?

When two or more monosaccharides are joined together by condensation reactions

4

How are polysaccharides broken down into their constituent monosaccharides?

By a hydrolysis reaction

5

What are 3 polysaccharides?

Starch
Glycogen
Cellulose

6

Polysaccharide Starch - How do cells get energy?

Glucose

7

Polysaccharide Starch - What do plants store excess glucose as?

Starch

8

Polysaccharide Starch - When a plant needs more glucose for energy, what does it do?

Breaks down starch to release glucose

9

Polysaccharide Starch - How do plants get energy?

The cells get energy from glucose
The plants store the glucose as starch
When the plant needs more glucose for energy it breaks down the starch releasing the glucose

10

Polysaccharide Starch - What is starch a mixture of?

Two polysaccharides of alpha glucose: Amylose and Amylopectin

11

What is the structure of Amylopectin?

Long
Unbranched chain of a-glucose
Angles of glycosidic bonds give it a coiled structure
Hydrogen bonds hold its helical structure

12

Polysaccharide Starch - What is the function of Amylose?

Compact
Good for storage
Can fit more in a small space

13

Polysaccharide Starch - What is the structure of amylopectin?

Long
Branched chain of a-glucose
Side branches

14

Polysaccharide Starch - What is the function of amylopectin?

Side branches allow the enzymes to break down the molecule to get at the glycosidic bonds easily
Glucose can be released quickly

15

Polysaccharide Starch - What is starch in water?

Insoluble
Doesn't affect water potential

16

Polysaccharide Starch - How is starch good for storage? (Water)

Doesn't cause water to enter cells by osmosis which would make them swell

17

Polysaccharide Glycogen - How do animal cells get energy?

From glucose

18

Polysaccharide Glycogen - What do animals store excess glucose as?

Glycogen

19

Polysaccharide Glycogen - What is the structure of glycogen?

Long
Branched chain of a-glucose
Lots of side branches

20

Polysaccharide Glycogen - What is glycogen's function?

Lots of side branches means stored Glucose can be released quickly
Compact so it is good for storage
Acts as an energy store

21

Polysaccharide Cellulose - What is the structure of cellulose?

Long
Unbranched chains of b-glucose
When b-glucose molecules bond they form straight cellulose chains
Chains linked together by hydrogen bonds to form microfibrils

22

Polysaccharide Cellulose - What is the function of cellulose?

Strong fibres (microfibrils) mean cellulose provides structural support for cells