Biological Molecules - Carbohydrates

Question 1

What elements do all Carbohydrates contain?

Answer 1

C, H, and O

Question 2

What monomers are Carbohydrates made from?

Answer 2

Monosaccharides

Question 3

Give 3 examples of a Monosaccharide.

Answer 3

1. Glucose
2. Fructose
3. Galactose

Question 4

What kind of sugar is Glucose?

Answer 4

A Hexose sugar

Question 5

What is a Hexose sugar?

Answer 5

A monosaccharide with 6 carbon atoms in each molecule

Question 6

What are the 2 types of glucose?

Answer 6

1. Alpha Glucose

2. Beta Glucose

Question 7

Draw out the structure of an Alpha Glucose.

Answer 7

Refer to textbook.

Question 8

Draw out the structure of a Beta Glucose.

Answer 8

Refer to textbook.

Question 9

How is a Disaccharide formed?

Answer 9

2 Monosaccharides join together by a condensation reaction

Question 10

What bond is formed between 2 monosaccharides?

Answer 10

Glycosidic Bond

Question 11

What monosaccharides form Maltose?

Answer 11

Alpha Glucose + Alpha Glucose

Question 12

What monosaccharides form Sucrose?

Answer 12

Glucose + Fructose

Question 13

What monosaccharides form Lactose?

Answer 13

Glucose + Galactose

Question 14

Describe the Benedict’s Test for Reducing Sugars.

Answer 14

1. Heat sample with Benedict’s Reagent
2. +ve = Brick Red Precipitate
   • ve = Sample stays Blue

Question 15

Describe the test for Non-Reducing Sugars.

Answer 15

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

Question 16

How is a Polysaccharide formed?

Answer 16

More than 2 monosaccharides join together by a condensation reaction

Question 17

Give 3 examples of a Polysaccharide.

Answer 17

1. Starch
2. Glycogen
3. Cellulose

Question 18

How do plants use Starch?

Answer 18

Plants store excess glucose as starch

Question 19

Which 2 polysaccharides make up starch?

Answer 19

Amylose & Amylopectin

Question 20

What is Amylose?

Answer 20

A long, unbranched chain of alpha glucose

Question 21

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

Answer 21

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

Question 22

What is Amylopectin?

Answer 22

A long, branched chain of alpha glucose

Question 23

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

Answer 23

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

Question 24

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

Answer 24

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

Question 25

How do animals use Glycogen?

Answer 25

Animals store excess glucose as glycogen

Question 26

What is Glycogen?

Answer 26

A polysaccharide of alpha glucose

Question 27

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

Answer 27

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

Question 28

What is cellulose made up of?

Answer 28

Long, unbranched chains of beta glucose

Question 29

What happens when beta glucose molecules bond?

Answer 29

They form straight cellulose chains

Question 30

What are cellulose chains linked together by?

Answer 30

Hydrogen bonds to form microfibrils

Question 31

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

Answer 31

Microfibrils means cellulose provides structural support for cells

Question 32

Describe the Iodine Test for Starch.

Answer 32

1. Add iodine dissolved in potassium iodide to the test sample
2. +ve= color change from browny-orange to blue-black