8-1 Photosynthesis

Heterotrophs and Autotrophs Autotroph= organisms like plants, that can make their own food. Heterotroph=animals that cannot use the sun’s energy directly, they obtain energy from the food they eat.

ATP Adenosine triphosphate The characteristics of ATP make it exceptionally useful as the basic energy source of all cells

Triphosphate means 3 phosphate groups, this is like a full battery. When your cells break the bond between the phosphates energy is released and it leaves ADP = adenosine diphosphate = 2 phosphates ADP is like a used battery Your cells can “recharge” ADP by adding a phosphate and making ATP.

Photosynthesis 8-2 Plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates and oxygen as a waste product High energy carbohydrates = sugars and starches, mainly Glucose

The Photosynthesis equation 6CO2 + 6H2O + light C6H12O6 +6O2 (Reactants) (Products) Carbon dioxide + water + light is converted into glucose + oxygen

Where does Photosynthesis take place? Chloroplasts

Light and Pigments In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll, a molecule in chloroplasts Pigments = light-absorbing molecules found in plants that gather the sun’s energy Chlorophyll = plants main pigment that absorbs light, “energy”

Factors affecting Photosynthesis Water – plants need water so if there is none photosynthesis will slow or stop Temperature – it depends on enzymes which work best between 0°c and 35°c Intensity of light – increase the intensity of light and the rate of photosynthesis will increase