pHOTOSYNTHESIS HOW PLANTS MAKE FOOD

Autotrophs and Heterotrophs Organisms able to use light energy from the sun to produce food Example: plants Organisms that cannot use the sun’s energy directly to obtain energy Example: animals

Energy Forms of energy: light, chemical, electrical, heat ATP – adenosine triphosphate Fuels cellular activities Consists of adenine (contains N), ribose (sugar), and three phosphate groups

Energy When used, it loses a phosphate: becomes ADP Full vs. used battery Can be recharged Examples of uses: active transport, movement of organelles within the cell along microtubules

An Overview: Plants use sunlight to convert water and carbon dioxide into oxygen and carbohydrates. Wavelengths of light are seen as different colors. Plants gather energy from light using molecules called, “pigments.”

An Overview: Chlorophyll is the primary pigment (types a and b) It absorbs red and blue well, reflects green Other plant pigments (carotenoids and anthocyanins) are also present in leaves They make the beautiful fall colors! Light energy absorbed by chlorophyll excites electrons that power photosynthesis