Photosynthesis

Radiant energy absorbed

Photolysis occurs that hydrogen is released (goes to dark phase process) and O2 gets released into atmosphere as byproduct

Phosphorylation occurs that ATP gets produced

Occurs in grana

Light not required

CO2 from atmosphere absorbed and gets combined with H2 (with help of ATP) to produce glucose

Excess glucose gets stored as starch

Occurs in stroma

Importance of Photosynthesis

1. Balances levels of O2 and CO2 in atmosphere

2. Uses radiant energy to produce chemical potential energy (stored as starch) to serve as food for other organisms

3. Proteins and lipids are made by using the stored starch

Factors that affect the Rate of Photosynthesis

1. Intensity of Light

• Direct relationship between light intensity and rate of photosynthesis

• As light intensity increases, so does rate of photosynthesis

• Photosynthesis will occur most rapidly at the optimum light intensity

• If light intensity is beyond optimum amount, the rate will remain constant and the other factors will act as limiting factors

2. Concentration of Carbon dioxide

• Direct relationship

• At optimum level, photosynthesis will occur most rapidly

• If above optimum amount, photosynthesis will remain constant

  Why?

  Dark phase cannot take place more quickly than what it does at optimum level

3. Temperature

• As temperature increases, so does rate of photosynthesis

• Once it reaches the optimum temperature, it will reach the maximum rate of photosynthesis

• If it goes beyond optimum temperature the rate will decrease

  Why?

  The enzymes used in this process will denature at high temperatures

4. Availability of water

• Plants cannot survive without water

• Less water = less photosynthesis

5. Chlorophyll concentration

• Directly proportional

6. O2 concentration

• Indirectly proportional

• O2 is a byproduct of photosynthesis

Greenhouse Effect Importance