Topic 1 - carbohydrates 1

Question 1

what are the 2 functions of carbohydrates

Answer 1

• usable energy source
• storing energy
• ## makes up the cell wall in plants and fungi

Question 2

which organic molecules are carbohydrates made up of

Answer 2

carbon, hydrogen and oxygen

Question 3

what are the 3 main groups of carbohydrates

Answer 3

• monosaccharides
• disaccharides
• polysaccharides

Question 4

what number of carbon atoms does a triose sugar have

Answer 4

3

Question 5

what number of carbon atoms does a pentose sugar have

Answer 5

5

Question 6

what number of carbon atoms does a hexose sugar have

Answer 6

6

Question 7

give 2 examples of pentose sugars

Answer 7

ribose and deoxyribose

Question 8

give 3 examples of hexose sugars

Answer 8

glucose, galactose, fructose

Question 9

what are isomers

Answer 9

molecules that have the same chemical formula, but different molecular structures

Question 10

give and example of 2 isomers

Answer 10

alpha-glucose and beta-glucose

Question 11

what is the difference in structure between alpha-glucose and beta-glucose

Answer 11

alpha-glucose has hydrogen on top and the hydroxyl group at the bottom, whilst the beta-glucose has the 2 groups swapped around

Question 12

draw the structure of alpha-glucose

Question 13

draw the structure of beta-glucose

Question 14

draw the structure of ribose

Question 15

what is a disaccharide

Answer 15

2 monosaccharides joined together in a condensation reaction, resulting in a glycosidic bond

Question 16

what are the products of a condensation reaction

Answer 16

• 1 molecule of water is removed
• glycosidic bond
• disaccharide

Question 17

what is starch

Answer 17

a long chain polymer formed of alpha-glucose monomers

Question 18

what is sucrose

Answer 18

a sweet tasting disaccharide formed by the joining of alpha-glucose and fructose by a glycosidic bond

Question 19

which type of sugar is glucose

Answer 19

hexose sugar

Question 20

what is DNA

Answer 20

a nucleic acid that acts as the genetic material in many organisms

Question 21

what is RNA

Answer 21

a nucleic acid which can act as the genetic material in some organisms and is involved in protein synthesis

Question 22

what is a condensation reaction

Answer 22

a reaction in which a molecule of water is removed from the reacting molecules as a glycosidic bond is formed between them

Question 23

what is a glycosidic bond

Answer 23

a covalent bond formed between 2 monosaccharides in a condensation reaction

Question 24

what are reducing sugars

Answer 24

sugars that react with blue Benedict’s solution and reduce the copper(II) ions to copper(I) ions giving an orangey-red precipitate

Question 25

what are non-reducing sugars

Answer 25

sugars that do not react with Benedict’s solution

Question 26

out of which monosaccharides is sucrose made out of

Answer 26

alpha glucose + fructose

Question 27

out of which monosaccharides is lactose made out of

Answer 27

alpha-glucose +
beta-glucose

Question 28

out of which monosaccharides is maltose made out of

Answer 28

alpha-glucose +
alpha-glucose