Limiting Factors

What happens during photosynthesis? light energy carbon dioxide water oxygen glucose chlorophyll Why is this useful to all living organisms?

What is photosynthesis? What happens in summer to the grass when it rains a lot? Why does this happen? Some commercial growers pump extra CO2 into their greenhouses for crops like tomatoes. Why?

Limiting factors (1) Weak bicarbonate solution No bicarbonate solution Oxygen collected Bicarb solution Pond weed No bicarbonate solution Weak bicarbonate solution Strong bicarbonate solution What is the bicarb for? What variables are we controlling?

What is happening here?

Carbon dioxide concentration Rate of photosynthesis increases with light to a point We will reach a point when no matter how much carbon dioxide you add the rate of photosynthesis stays the same Carbon dioxide concentration is no longer the limiting factor

Limiting factors (2) Light Dark What variables are we controlling? Oxygen collected Bicarb solution Pond weed Light Dark What variables are we controlling? What did we find out?

What are we investigating in this experiment?

Light intensity Rate of photosynthesis increases with light to a point We will reach a point when no matter how close the light is (the intensity of light) the rate of photosynthesis stays the same Light intensity is no longer the limiting factor

What is happening here?

Temperature What do we know about rate of reaction and temperature? Photosynthesis is controlled by enzymes. Enzymes are made of protein. What happens to proteins as they get hotter? Modest increases in temperature will speed up a chemical reaction but above a certain temperature rates will start to fall