8 1 Photosynthesis Heterotrophs and Autotrophs Autotroph organisms
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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 § 6 CO 2 + 6 H 2 O + light (Reactants) C 6 H 12 O 6 +6 O 2 (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
