Photosynthesis

Question 1

Describe five limiting factors of photosynthesis and explain how each factor affects the rate of photosynthesis.

Answer 1

Temperature- If temperatures are too low, molecules have less kinetic energy (speed of molecules is lower), resulting in less successful collisions between enzymes and substrates, reducing rate of photosynthesis. If temperatures are too high, enzymes (that control rate of photosynthesis) will denature, reducing the rate of photosynthesis.

pH- Enzymes that control the rate of photosynthesis are altered when changes to pH occurs. This can denature the enzymes, reducing the rate of photosynthesis.

Light availability- An increase in light availability will increase rate of photosynthesis, as light energy is required.

Water/CO2 availability- Reactants required for photosynthesis. Hence an increase in water/carbon dioxide will increase the rate of photosynthesis.

Chlorophyll- Green pigment that absorbs light. More chlorophyll available will increase the rate of photosynthesis

Chloroplasts- Site of photosynthesis – more chloroplasts will increase the rate of photosynthesis.

Question 2

State the word and chemical equations for photosynthesis.

Answer 2

Carbon dioxide + water -> glucose + oxygen (chlorophyll and light must be over/under the arrow)
6CO2 + 6H2O -> C6H12O6 + 6O2

Question 3

Where in the cell does photosynthesis take place?

Answer 3

Chloroplasts (in plant cells)

Question 4

State the energy conversion that occurs in photosynthesis.

Answer 4

Light -> Chemical