Topic 11

Question 1

Functions of nutrients

Answer 1

Provide energy, raw materials, help organisms stay healthy

Question 2

Carbohydrates

Answer 2

Carbon, hydrogen, oxygen
Source of energy

Question 3

Single sugars

Answer 3

Glucose, fructose

Question 4

Double sugars

Answer 4

2 single sugar - 1 water
Maltose- 2 glucose-1 water, commonly found in cereal and grain
Sucrose- 1 glucose+1 fructose-1 water, commonly found in sugarcane, fruits, storage roots

Question 5

Complex Carbs

Answer 5

Many glucose molecules
Starch- long straight chains, storage in plants
Glycogen- highly branced chains, storage in animals and fungi, found in liver and muscle
Cellulose- straight chains held together by hydrogen bonds, form cell wall

Question 6

protein

Answer 6

carbon hydrogen oxygen nitrogen (sulfur)
synthesise new protoplasm for growth and repair
synthesise enxymes
excess protein broken down
formed by amino acids

Question 7

amino acids

Answer 7

peptide bonds linked to form polypeptide chains

Question 8

Fats / lipids

Answer 8

Carbon hydrogen oxygen
3 fatty acid + 1 glycerol
solvent for vitamins
layer of insulation
source and storage of energy
excess stored as adipose tissue

Question 9

Iodine test

Answer 9

starch
add few drops of iodine solution
present: black/blue-black
absent: brown

Question 10

benedict´s test

Answer 10

reducing sugars (glucose fructose maltose)
add 2cm3 of sample and benedict solution, mix, place in boiling water for 5 min
brick red precipitate
orange/ yellow
green
blue

Question 11

biuret

Answer 11

protein
add 2cm3 sample and sodium hydroxide, mix, add copper sulfate drop by drop
violet
blue

Question 12

ethanol emulsion

Answer 12

fats
add 2cm3 of sample and ethanol, mix, add 2cm3 water, mix