Photosynthesis

Question 1

describe how carbon-dioxide concentration can affect the rate of photosynthesis

Answer 1

it is one of the reactants needed for plants to make glucose. the rate of photosynthesis will increase when a plant is given higher concentrations of carbon-dioxide up to a point.

Question 2

describe how temperature can affect the rate of photosynthesis

Answer 2

as the environment warms up, chemical reactions speed up. photosynthesis is an enzyme controlled reaction: if the temperature increases too much, then the enzymes become denatured and the rate of reaction will decrease and stop.

it is a limiting factor of photosynthesis

Question 3

describe how the amount of light can affect the rate of photosynthesis

Answer 3

plants found in an areas of lower light do not tend to grow as tall.

light intensity decreases as the distance between the plant and light source increases

Question 4

explain why very high light intensities may slow down the rate of photosynthesis.

Answer 4

saturation of the active sites in the enzymes catalysing the reactions
bleaching of chlorophyll

Question 5

suggest how farmers apply their knowledge of limiting factors to improve crop yield.

Answer 5

• heating can be used to provide optimum temperatures for maximum plant growth.
• artificial lighting enhances the natural sunlight especially overnight and on cloudy days
• extra carbon-dioxide gas can be pumped into the air inside the greenhouses

Question 6

suggest what the glucose produced in photosynthesis may be used for

Answer 6

• respiration
• converted into insoluble starch for storage
• used to produce fat or oil for storage
• to produce cellulose: strengthens the cell wall
• produces amino acids for protein synthesis