Unit 1- Carbohydrates

Question 1

What elements make up carbs?

Answer 1

C,H,O

Question 2

Give 3 examples of hexose sugars

Answer 2

Glucose
Galactose
Fructose

Question 3

Give 3 examples of pentose sugars

Answer 3

Ribose, deoxyribose, ribulose (photosynthesis)

Question 4

Describe the structure of Alpha glucose

Answer 4

Carbon hexose ring with an oxygen in the top right corner
Methyl group with an OH on the top left carbon
Both the OH groups on side carbons face down

Question 5

Describe the structure of Ribose

Answer 5

Carbon pentose ring with oxygen as the top point
Methyl group on carbon adjacent the oxygen
Methyl group also has a OH group
Every other carbon has OH group apart from carbon with methyl group

Question 6

What joins 2 monosaccharides

Answer 6

Glycosidic bond (COC)

Question 7

What type of reaction is polymerisation

Answer 7

Condensation

Question 8

What type of reaction is the breakdown of polysaccharides

Answer 8

Hydrolysis

Question 9

Everything we know about maltose:

Answer 9

• disaccharide of 2 glucose molecules

- formed from digestion of starch by amylase

Question 10

Everything we know about sucrose

Answer 10

• glucose fructose disaccharide

- less reactive than glucose so plants use it to transport sugar

Question 11

Everything we know about lactose

Answer 11

• galactose and glucose disaccharide

- found in mammalian milk

Question 12

Definition of a polysaccharide

Answer 12

Chains of glucose monomers joined together by glycosidic bonds

Question 13

Benefit of using starch as a storage

Answer 13

• compact

- insoluble so doesn’t change water potential of the cell resulting in osmosis and lysis of cells

Question 14

Structure of amylose

Answer 14

It is a poly (1-4) glucose, Long glucose chain that coils into an alpha helix
- more compact with less branches

Question 15

Structure of amylopectin and a benefit of this

Answer 15

Made of 1-4 glucose with some 1-6 branches

- more ends means it can be hydrolysed at more places by amylase enzymes releasing more energy per second

Question 16

Where is glycogen found?

Answer 16

Muscle and liver cells

Question 17

Everything we know about glycogen:

Answer 17

• animal storage of sugars
• lots of branches
• broken down to glucose by glycogen phosphorylase
• many ends means it releases lots of energy per second

Question 18

Structure of cellulose?

Answer 18

Poly (1-4) glucose, of Beta glucose which forms rigid glycosidic bonds
- cellulose chains are straight and linked together with hydrogen bonds to form microfibrils which give the strength to cell walls