Nutrition

Question 1

Describe test for starch

Answer 1

Iodine solution: turn blue/black

Question 2

Describe test for reducing sugar

Answer 2

Benedict solution:
- Beaker filled with boiling water placed on heat proof mat
- Same volume of Benedicts solution to the food extract- put in hot water
Positive result: red/orange

Question 3

Describe test for fat

Answer 3

• Add ethanol to the extract of food in a clean test tube
• Bunk over the open and shake up the content
• Add distilled water half full
• Positive test: white emulsion, cloudy white

Question 4

Importance of vitamin C and D

Answer 4

• tissue repair(bleeding gums, resistance to disease

- strengthen bones and teeth.

Question 5

List the principal sources and importance of mineral salts(iron and calcium only)

Answer 5

-Iron(liver,meat): transport of oxygen

Calcium(milk,fish):strengthen bones and teeth

Question 6

Describe the deficiency symptoms if vitamins C and D

Answer 6

• Bleeding gums

- Soft bones

Question 7

Describe the deficiency symptoms for mineral salts(iron and calcium)

Answer 7

• Weak, brittle bones and teeth

- Tiredness,lack of energy

Question 8

Describe the use of microorganisms in the manufacture of yoghurt

Answer 8

• The bacteria Lactobacillus break down the sugar lactose to form lactic acid.
• Lactic acid lowers the pH of yogurt, which helps to preserve and denatures milk protein

Question 9

Define photosynthesis

Answer 9

The fundamental process by which plants manufacture carbohydrates from raw materials using energy from light

Question 10

Word equation for photosynthesis

Answer 10

carbon dioxide+water - glucose+oxygen

Question 11

Why chlorophyll traps light energy and converts it into chemical energy?

Answer 11

For the formation of carbohydrates and their subsequent storage
- From water and carbon dioxide, the energy split water into hydrogen ions which reduce carbon dioxide into carbohydrates.

Question 12

List the use of glucose as a by product of photosynthesis

Answer 12

• Respiration in leaf
• Some of glucose changed into starch/stored in leaves in future
• Used to make cellulose, make cell walls
• Converted to sucrose- transported to phloem

Question 13

State the effect of varying light intensity

Answer 13

Rate increase if light increases

Question 14

Describe test for protein

Answer 14

5 to 6 drops to the food extract

Positive test: purple/violet

Question 15

Describe the internal features of the leaf for photosynthesis

Answer 15

• Chloroplast in the palisade mesophyll are near the upper surface of the leaf the maximize absorption of light
• Stomata open to allow carbon dioxide diffuse in the leaf

Question 16

Why leaves are thin?

Answer 16

So carbon dioxide does not have to diffuse far from the atmosphere to the cell of palisade and spongy mesophyll.

Question 17

Stomata are opened and closed by what?

Answer 17

Guard cell

Question 18

Describe the importance of nitrate ions for protein synthesis.

Answer 18

To make amino acids which are used to make proteins

Question 19

Describe the importance of magnesium ions for chlorophyll synthesis

Answer 19

Absorbed by plants and used to make chlorophyll.

Question 20

Explain the effects of nitrate ion efficiency on plant growth

Answer 20

Helps make amino acids which make protein, lack of this ion, plant will show poor growth

Question 21

Explain the effects of magnesium ion efficiency on plant growth

Answer 21

Used to make chlorophyll, lack of this ion will make yellow leaves.

Question 22

What is nitrogen-containing fertilizer?

Answer 22

Is a compound that is added to plant to stimulate chloroplast(growth) in plant for photosynthesis

Question 23

Dangers of overuse the nitrogen fertilizers.

Answer 23

-Harmful for agriculture, plasmolysis take place, water passes from plants to soil- wilting of the plants