Carbohydrates

Question 1

chemical components of carbs

Answer 1

carbon, hydrogen, oxygen

Question 2

3 types of carbs

Answer 2

monosaccharides, disaccharides and polysaccharides

Question 3

generalised chemical formula for monosaccharides

Answer 3

CnH2nOn

Question 4

2 types of pentose sugars

Answer 4

ribose and deoxyribose

Question 5

chemical formula for ribose

Answer 5

C5H10O5

Question 6

chemical formula for deoxiribose

Answer 6

C5H10O4

Question 7

3 hexose sugars

Answer 7

glucose
fructose
galactose

Question 8

two types of glucose

Answer 8

alpha
beta

Question 9

what are the three properties of all monosacharides

Answer 9

all soluble (in water)
sweet
crystalline

Question 10

how is a disaccharide formed?

Answer 10

a condensation reaction between two monosaccharides resulting in a glycosidic bond

Question 11

3 disaccharides

Answer 11

maltose
sucrose
lactose

Question 12

which disaccharide is the only non-reducing sugar in AQA?

Answer 12

sucrose

Question 13

reducing sugars

Answer 13

all monosaccharides + maltose and lactose

Question 14

monomer

Answer 14

single unit that can react with other units to form a larger molecule, polymer or macromolecule

Question 15

polymer

Answer 15

a chain of repeating monomer

Question 16

condensation reaction

Answer 16

a molecule of water is formed when two monomers are joined together to form a polymer

Question 17

hydrolysis reaction

Answer 17

water is added to a covalent bond between monomers and monomers separate

Question 18

why is glucose important?

Answer 18

it is the main RS substrate in all organisms as is the way carbs are transported in animals

Question 19

where is the OH in alpha glucose

Answer 19

below the first carbon

Question 20

where is OH in beta glucose?

Answer 20

above C1

Question 21

structural isomer

Answer 21

two molecules with the same chemical formula bt different structural formulas

Question 22

name 2 pairs of structural isomers

Answer 22

1. alpha and bet glucose
2. fructose and glactose

Question 23

why are ribose and deoxyribose not structural isomers?

Answer 23

deoxyribose has one less carbon atom than ribose so they are not true isomers

Question 24

where is the glycosidic bond between two glucose molecules in maltose?

Answer 24

between C1 of one molecule and C4 of another

Question 25

bond in maltose

Answer 25

alpha 1-4 glycosidic bond

Question 26

bond in sucrose

Answer 26

alpha 1-4 glycosidic bond

Question 27

bond in lactose

Answer 27

beta 1-4 glycosidic bond

Question 28

how to determine the chemical formula of a disaccharide?

Answer 28

the chemical formulas for the two monosaccharides - H2O

Question 29

word formula for formation of sucrose

Answer 29

alpha glucose + fructose -> sucrose and water

Question 30

function of cellulose

Answer 30

structural function

Question 31

function of all polymers of alpha glucose

Answer 31

to store glucose

Question 32

structure to function of starch: compact shape

Answer 32

fit more in less spaces therefore store more glucose in a cell

Question 33

structure to function of starch: large size

Answer 33

store more glucose nd cnt leave cel by cell membrane

Question 34

structure to function of starch: polymer

Answer 34

can be easily hydrolysed to release glucose for aerobic respiration

Question 35

structure to function of starch: branched in some way

Answer 35

increases SA as more ends for hydrolysis, giving faster release of glucose

Question 36

structure to function of starch: insoluble in water

Answer 36

osmotically inert (doesn't affect WP)

Question 37

why can't we store glucoe as glucose?

Answer 37

would decrease WP

Question 38

what enzyme hydrolyses starch?

Answer 38

amylase

Question 39

two components of starch and their %s

Answer 39

amylose = 30% amylopectin =70%

Question 40

structure of amylose

Answer 40

polymer of alpha glucose with 1-4 glycosidic bonds all facing down helical shape

Question 41

structure of amylopectin

Answer 41

polymer of alpha glucose with 1-4 and 1-6 glycosidic bonds branched structure bc of 1-6 bonds

Question 42

structure of glycogen

Answer 42

a polymer of alpha glucose with 1-4 and 1-6 glycosidic bonds more branched than amylopectin as more 1-6 bonds

Question 43

enzyme that hydrolyses glycogen

Answer 43

glycogen phosphorylase

Question 44

why does glycogen have to be more branched?

Answer 44

animals have a higher metabolic rate than plants so require glucose faster more branching increases SA so there is faster release

Question 45

structure of cellulose

Answer 45

a chain of beta glucose molecules connected by 1-4 glycosidic bonds which alternate in upward and downwards position resulting in a straight chain.

Question 46

structure of a microfibril

Answer 46

several cellulose chains stack on top o one another, joined by hydrogen bonds

Question 47

features and function of a microfibril

Answer 47

high tensile strength due to many hydrogen bonds betweeen chains, giving high tensile strength to the cell wall of plant cells

Question 48

What is OH

Answer 48

Hydroxyl group