Topic 4- Bioenergetics

Question 1

Is photosynthesis endothermic or exothermic?

Answer 1

Energy is transferred from the environment in the process.

Question 2

What does chlorophyll do?

Answer 2

Absorbs light

Question 3

5 ways glucose is used in plants

Answer 3

Respiration- converting glucose into other substances
Making cellulose- for cell walls
Amino acids- glucose and nitrate ions from soil to make amino acids
Stored as lipids- in seeds
Stored as starch- in roots stems and leaves for winter when photosynthesis can’t happen.

Question 4

Why is glucose also stored as starch

Answer 4

Starch is insoluble so better for storing- a cell with lots of glucose would draw lots of water and swell up.

Question 5

3 things rate of photosynthesis is affected by

Answer 5

Light intensity, CO^2 concentration and temperature.

Question 6

Explain how chlorophyll can be a limiting factor

Answer 6

Disease or lack of nutrients can cause chloroplasts to not make enough chlorophyll so they can’t absorb as much light.