Photosynthesis

Ways to Obtain Energy Autotroph Heterotroph Use energy from the sun to make organic compounds Makes its own food through photosynthesis Heterotroph Get energy from food instead of directly from sunlight or inorganic substances Not able to make its own food

Photosynthesis The process of converting light energy from the sun into chemical energy in the form of organic compounds, primarily carbohydrates

Parts of Photosynthesis Light Reactions Light energy is converted to chemical energy, which is temporarily stored in ATP and the energy carrier molecule NADPH. Calvin Cycle Organic compounds are formed using CO2 and the energy stored in ATP and NADPH.

Capturing Light Energy Absorption of light happens in the chloroplasts 2 membranes Inside the inner membrane is another system of membranes called the thylakoids Arranged as flattened sacs The thylakoids are connected and layered in flattened stacks called grana (granum) All the grana is surrounded by a solution called stroma

Capturing Light Energy Cont. The pigment chlorophyll in the thylakoids reflects green light and absorbs the other colors of the spectrum

Factors that Affect Photosynthesis Light Intensity The rate of photosynthesis increases as light intensity increases CO2 Levels Increasing levels of carbon dioxide stimulate photosynthesis Temperature Rate of photosynthesis only increases to a point and then the stomata begin to close and limit CO2 entry and water loss