CELLS & ENERGY Ch's 6&7 Need energy to: move change shape repair structure make new cell parts transport food expel wastes

Sun is ultimate source of energy Autotrophs – make own food Heterotrophs – eat other orgs Energy is obtained through Biochemical Pathways = linked chemical reactions (product of one is reactant of another)

2 Important Pathways Photosynthesis- Light energy converted to chemical energy of organic compounds (carbs) Autotrophs only Cellular Respiration- Organic compounds broken down to produce energy in a form a chemical compounds ATP Autotrophs & Heterotrophs

PHOTOSYNTHESIS 6CO2 + 6H20 + solar energy C6H12O6 + 6O2 Occurs in leaves where chloroplasts are abundant

Plants contain pigments (compounds that absorb light) Chlorophyll – reflects green light (green leaves); uses red & blue Carotenoids – reflect yellow, orange, brown (fruits/flowers)

CELLULAR RESPIRATION C6H12O6 + 6O2 6CO2 + 6H2O + energy Process by which all organisms release energy stored in organic molecules Connection between photosynthesis and respiration

2 STAGES In cytoplasm Glucose is broken down: 2 smaller molecules result. In mitochondria those 2 molecule combine to Oxygen to form CO2

Fermentation is a type of respiration in which some organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid. For example, yeast perform fermentation to obtain energy by converting sugar into alcohol. Bacteria perform fermentation, converting carbohydrates into lactic