Harnessing the Sun’s light to make ENERGY Photosynthesis Harnessing the Sun’s light to make ENERGY

Review Energy: the ability to do work For all life, energy originally comes from the SUN Examples: light, heat, electricity, stored in chemical compounds Autotrophs: organisms (i.e. plants) that use light from the Sun to make food (glucose) Heterotrophs: organisms that get their energy from eating other organisms (either autotrophs or other heterotrophs)

ATP and ADP: chemicals that power cell activities ATP: chemical compound that living things use to store energy Adenosine triphosphate (adenosine + ribose + 3 phosphate groups) “Fully charged battery” ADP: chemical compound that stores energy but is less powerful than ATP Adenosine diphophste (adenosine + ribose + 2 phosphate groups) “Partially charged battery”

Plant cells generate ATP from ADP by using the energy from the Sun, then use it to make sugars

Photosynthesis: using the energy of sunlight to convert water & carbon dioxide into oxygen & high-energy sugars 6CO2 + 6H2O ---> C6H12O6 + 6O2

How do plants absorb light? Pigments – substances that absorb visible light Chlorophyll – green pigments located within the chloroplasts of plants

Chloroplasts are green because they absorb all the other wavelengths of light

Photosynthesis (2 stages) (Photo…) Light-dependent reactions requires light, produces oxygen gas and converts ADP to ATP (…Synthesis) Calvin cycle or Dark-reactions uses ATP from the light-dependent reactions to produce high energy sugars (sucrose/glucose)

Chloroplast Picture Color, copy, and label the chloroplast (figure 8-7, page 209) Glue/tape into your notebooks at the end of today’s notes Check off with me for points (10 total)