B8 Photosynthesis

Question 1

What is photosynthesis

Answer 1

Photosynthesis is the process by which green plants (and some bacteria) make their food. They use raw substance (carbon dioxide and water) and light energy to combine these substances to make glucose and oxygen.

Glucose is needed in the plant, oxygen is released (some is used up in respiration).

Question 2

What type of reaction is photosynthesis?

Answer 2

Photosynthesis is an endothermic reaction. It requires light energy which is trapped by the chlorophyll in the chloroplasts.

Question 3

What is the word equation for photosynthesis

Answer 3

Carbon dioxide + water -> glucose + oxygen

Question 4

What’s the chemical equation for photosynthesis

Answer 4

6CO2 + 6H2O -> C6H12O6 + 6O2

Question 5

What does a plant use the glucose made in photosynthesis for?

Answer 5

Used for respiration to release energy

Converted into insoluble starch for storage until it is needed

Used to produce fat, or oil for storage

Used to make other carbohydrates e.g. cellulose which strengthens the cell wall

Used to produce amino acids for protein synthesis.

Question 6

What is a limiting factor?

Answer 6

When a process (e.g. photosynthesis) depends on two or more factors (/substances), the rate of that process is limited by the factor which is in shortest supply

Question 7

Which factors could limit the rate of photosynthesis?

Answer 7

Light intensity

Availability of water

Temperature

Carbon dioxide concentration

Amount of chlorophyll in the leaves