Biological Molecules - Carbohydrates Flashcards Preview

AQA A Level Biology > Biological Molecules - Carbohydrates > Flashcards

Flashcards in Biological Molecules - Carbohydrates Deck (32)
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1

What elements do all Carbohydrates contain?

C, H, and O

2

What monomers are Carbohydrates made from?

Monosaccharides

3

Give 3 examples of a Monosaccharide.

1. Glucose
2. Fructose
3. Galactose

4

What kind of sugar is Glucose?

A Hexose sugar

5

What is a Hexose sugar?

A monosaccharide with 6 carbon atoms in each molecule

6

What are the 2 types of glucose?

1. Alpha Glucose
2. Beta Glucose

7

Draw out the structure of an Alpha Glucose.

Refer to textbook.

8

Draw out the structure of a Beta Glucose.

Refer to textbook.

9

How is a Disaccharide formed?

2 Monosaccharides join together by a condensation reaction

10

What bond is formed between 2 monosaccharides?

Glycosidic Bond

11

What monosaccharides form Maltose?

Alpha Glucose + Alpha Glucose

12

What monosaccharides form Sucrose?

Glucose + Fructose

13

What monosaccharides form Lactose?

Glucose + Galactose

14

Describe the Benedict's Test for Reducing Sugars.

1. Heat sample with Benedict's Reagent

2. +ve = Brick Red Precipitate
-ve = Sample stays Blue

15

Describe the test for Non-Reducing Sugars.

1. Heat a new sample with dilute HCl

2. Neutralize sample with NaHCO3

3. Heat sample with Benedict's Reagent

4. +ve = Brick Red Precipitate
-ve = Sample stays Blue

16

How is a Polysaccharide formed?

More than 2 monosaccharides join together by a condensation reaction

17

Give 3 examples of a Polysaccharide.

1. Starch
2. Glycogen
3. Cellulose

18

How do plants use Starch?

Plants store excess glucose as starch

19

Which 2 polysaccharides make up starch?

Amylose & Amylopectin

20

What is Amylose?

A long, unbranched chain of alpha glucose

21

Give one feature of Amylose and explain how it aids its function.

The angles of the glycosidic bond give it a coiled structure. This makes it compact, so it's really good for storage, as you can fit more into a small space

22

What is Amylopectin?

A long, branched chain of alpha glucose

23

Give one feature of Amylopectin and explain how it aids its function.

Its side branches allow the enzymes that break down the molecule to get at the glycosidic bonds easily. This means that the glucose can be released quickly

24

Give one feature of Starch and explain how it aids its function.

Starch is insoluble in water and doesn't affect water potential so it doesn't cause water to enter by osmosis, which would make them swell. This makes it good for storage

25

How do animals use Glycogen?

Animals store excess glucose as glycogen

26

What is Glycogen?

A polysaccharide of alpha glucose

27

Give 2 features of Glycogen and explain how it aids its function.

1. It has lots of side branches which means stored glucose can be released quickly, which is important for energy release in animals.

2. It's a very compact molecule so it's good for storage

28

What is cellulose made up of?

Long, unbranched chains of beta glucose

29

What happens when beta glucose molecules bond?

They form straight cellulose chains

30

What are cellulose chains linked together by?

Hydrogen bonds to form microfibrils

31

Give one feature of Cellulose and explain how it aids its function.

Microfibrils means cellulose provides structural support for cells

32

Describe the Iodine Test for Starch.

1. Add iodine dissolved in potassium iodide to the test sample

2. +ve= color change from browny-orange to blue-black