Trapping the Sun’s Energy The process by which plants capture energy from the sun to build carbohydrates (glucose) through chemical pathways is called photosynthesis

The equation that represents photosynthesis is: Solar energy converts water and carbon dioxide into chemical energy stored in simple sugars The equation that represents photosynthesis is: CO2 + H2O  C6H12O6 + O2 Solar energy

Phases of Photosynthesis Photosynthesis requires energy from the sun, but the sun is not available 24 hours a day. Occurs only in autotrophs Chlorophyll absorbs the sunlight to be used to power photosynthesis.

The Role of Chloroplasts and Pigments Photosynthesis takes place in the chloroplasts. Oxygen is the waste gas of photosynthesis.

Photosynthesis Equation Light Energy CO2 + H2O C6H12O6 + O2 chlorophyll Carbon Dioxide from the air Glucose Oxygen Released Water Plants can use this glucose molecule for energy during Cellular Respiration. Plants can also convert this glucose molecule into other organic compounds such as proteins and fats/lipids or other carbohydrates like starch and cellulose

4 Factors that Affect Photosynthesis Carbon Dioxide (CO2) Without CO2, the plant would not have one of the raw materials needed in the photosynthesis equation Temperature The temperature must be in the appropriate range for the plant in order for photosynthesis to properly occur

Intensity of Light If the intensity of light is lower, the available energy for photosynthesis is lower. In a greenhouse, if the light source is further away, intensity is lower and less photosynthesis can occur

If light is not available at all, the light-dependent reactions cannot occur (nor can they provide the materials used in the light-independent reactions)

What colors of light does photosynthesis work best at? Photosynthesis works best (high rate of reaction) in blue/ violet or orange light. The reaction doesn’t happen quickly with green light, because chlorophyll reflects green light (it doesn’t absorb green light) Violet Blue Green Yellow Orange Red

Water A shortage of water will decrease the rate of photosynthesis. Too much water can kill a plant because it will cause the roots to rot. http://www.youtube.com/watch?v=2xNwZCk2CHY&feature=related