Photosynthesis And The Environment

Question 1

Irradiance

Answer 1

• The light intensity per area on a leaf
• higher irradiance (sunny) mean more light energy available

Question 2

Photorespiration

Answer 2

• RuBisCo binds to O2 instead of CO2, which waste energy and carbon, as no sugar molecule is produced.
• occurs when oxygen has an greater concentration then co2

Question 3

CO2 Net intake

Answer 3

• refers to how much co2 in brought in?

•Net CO, Uptake = Photosynthesis - photorespiration - respiration

Cellular respiration - negative contribution
Photorespiration - negative contribution
Photosynthesis - positive contribution

Question 4

Co2 intake formula

Answer 4

PS - CR - PR

Question 5

O2 release formula

Answer 5

PR + CE - PS

Question 6

C3 light response curve - dark respiration rate

Answer 6

At dark photosynthesis co2 intake is negative. Cellular respiration is higher

Question 7

C3 light response curve - light compensation point

Answer 7

Co2 intake = Co2 release

This is the point where light is just enough to balance out CO₂ loss from respiration.

Question 8

C3 light response curve - light saturation point

Answer 8

Carbon fixation has reached its limit. Irriadiance is high, rubisco is taking in a lot of co2

Question 9

High concentration of oxygen

Answer 9

High level of oxygen Inhibits photosynthesis, as co2 and o2 compete for RuBisCo, which will always win

Question 10

What happens to stomata during high temperatures

Answer 10

During high temperatures, the stomata close to reduce water evaporation, meaning photosynthesis and CO2 intake drop