Limiting Factors (photosynthesis) Flashcards Preview

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Flashcards in Limiting Factors (photosynthesis) Deck (8)
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0
Q

What does it mean when the light intensity graph is increasing?

A
  • light intensity is limiting

* increasing light intensity increases the rate of photosynthesis

1
Q

What factors limit photosynthesis?

A

• light intensity - limits light dependent stage
- limits photophosphorylation
- limits photolysis of water
• CO2 availability
• temperature

2
Q

What does it mean when the light intensity graph plateaus?

A
  • light intensity is not limiting, CO2 conc or temp is

* increasing light intensity has no effect on rate of photosynthesis

3
Q

What does it mean when the CO2 availability graph is increasing?

A
  • CO2 is limiting

* as the concentration of CO2 increases so does the rate of photosynthesis

4
Q

What does it mean when the CO2 availability graph plateaus?

A
  • CO2 is not limiting

* decreasing the concentration of CO2 has no effect on the rate of photosynthesis

5
Q

What happens to the rate of photosynthesis when the temperature is under 25 degrees?

A
  • the photosynthesis rate approximately doubles every 10 degrees rise in temp
  • photosynthesis is at a higher rate than photorespiration
6
Q

What happens to the rate of photosynthesis when the temperature is over 25 degrees?

A
  • enzymes work less efficiently
  • oxygen competes more successfully for the active site of rubisco and prevents it from accepting CO2 (photorespiration).
  • photorespiration is at a higher rate than photosynthesis
7
Q

What happens to the rate of photosynthesis when the temperature is over 40 degrees

A
  • enzymes denature

* little or no photosynthesis