unit 1; carbohydrates

Question 1

what are carbohydrates

Answer 1

Carbohydrates are one of the main carbon-based compounds in living organisms

Question 2

what are the 3 types of carbohydrates

Answer 2

monosaccharides, disaccharides and polysaccharides

Question 3

definition of a monosaccharide

Answer 3

a single sugar monomer, all are reducing sugars

Question 4

definition of a disaccharide

Answer 4

a sugar formed by 2 monosaccharides, joined by a glycosidic bond in a condensation reaction

Question 5

definition of a polysaccharide

Answer 5

a polymer formed by many monosaccharides joined by glycosidic bonds in a condensation reaction

Question 6

what are the functions of a monosaccharide

Answer 6

source of energy in respiration, building blocks for polymers

Question 7

what are the functions of disaccharides

Answer 7

sugar found in germinating seeds(maltose), mammal milk sugar(lactose), sugar stored in sugar cane(sucrose)

Question 8

what are the functions of a polysaccharide

Answer 8

energy storage(plants-starch, animals- glycogen), structural(cell wall)

Question 9

what are covalent bonds in carbohydrates

Answer 9

glycosidic bonds

Question 10

what is the classification of reducing or non reducing sugars dependent on and which is which

Answer 10

the sugars ability to donate electrons, reducing sugars can donate electrons, non reducing sugars cannot

Question 11

why can reducing sugars be detected using Benedict’s reagent

Answer 11

they can reduce the soluble copper sulphate to insoluble brick-red copper oxide

Question 12

give examples of recuing sugars

Answer 12

glucose, fructose and galactose

Question 13

how are non reducing sugars detected

Answer 13

To be detected non-reducing sugars must first be hydrolysed to break the disaccharide into its two monosaccharides before a Benedict’s test can be carried out

Question 14

give an example of a non reducing sugar

Answer 14

sucrose

Question 15

is starch formed from alpha or beta glucose

Answer 15

alpha glucose

Question 16

what is the molecular formula of glucose

Answer 16

C6 H12 O6

Question 17

is glycogen formed from alpha or beta glucose

Answer 17

alpha glucose

Question 18

is cellulose formed from alpha or beta glucose

Answer 18

beta glucose

Question 19

what type of glycosidic bond does maltose have

Answer 19

A 1,4

Question 20

what type of glycosidic bond does sucrose have

Answer 20

A 1,2

Question 21

what type of glycosidic bond does cellulose have

Answer 21

B 1,4

Question 22

what type of glycosidic bond does amylose have

Answer 22

A 1,4

Question 23

what are the monosaccharide components of maltose

Answer 23

alpha glucose + alpha glucose

Question 24

what are the monosaccharide components of sucrose

Answer 24

alpha glucose + fructose

Question 25

what are the monosaccharide components of lactose

Answer 25

alpha glucose + galactose

Question 26

if the chains of a polysaccharide are folded what does this mean for the molecule

Answer 26

makes the molecule compact which is ideal for storage eg. starch and glycogen

Question 27

if the chains of a polysaccharide are straight what does this mean for the molecule

Answer 27

makes the molecules suitable to construct cellular structures e.g. cellulose