PHOTOSYNTHESIS

All plants need Sun Water CO2

Plants give us O2 Food

Review Everything that goes into a chemical reaction (reactants) must come also come out (products).

Apply it Photosynthesis is a chemical process that occurs in the chloroplasts of plant cells.

All plants need Sun Water CO2 REACTANTS

Plants give us O2 Food PRODUCTS

We’re almost done with that equation, but need to tweak it a little… carbon dioxide + water + sun food + oxygen C6H12O6 (nrg) nrg O2 CO2 + H2O + + We’re almost done with that equation, but need to tweak it a little…

Balanced equations have the same number of molecules on each side of the arrow (reactants and products). So, let’s balance it… 6CO2 + 6H2O nrg C6H12O6 6O2

4. How Does it Work? Plants absorb the suns’ energy with molecules called PIGMENTS. The primary pigments in plants are chlorophyll a and b.

5. Where does it happen?

STEP 1 – Light Dependent Rxns. 6. A two step process: STEP 1 – Light Dependent Rxns. Need: energy from sun, ADP, water Give off: ATP and Oxygen Happens in the thylakoid membranes

Step 2 – Light Independent Rxns. 6. A two step process Step 2 – Light Independent Rxns. Need: ATP and carbon dioxide Give off: ADP and glucose Happens in the stroma

6. The two steps Light Dep. Light Indep. Need: nrg, ADP, H2O ATP, CO2 Give: ATP, O2 ADP, C6H12O6 Remember that equation? 6CO2 + 6H20+ sun(nrg) C6H1206 + 6O2 (nrg)

6. The two steps Light Dep. Light Indep. Need: nrg, ADP, H2O ATP, CO2 Give: ATP, O2 ADP, C6H12O6 Remember that equation? 6CO2 + 6H20+ sun(nrg) C6H1206 + 6O2 (nrg)

7. What affects photosynthesis? Water Water up, photosyn. Up Water down, photosyn. Down Plants need to adapt to conserve water (waxy coatings, spines)

7. What affects photosynthesis? Temperature If temp is too high or too low, photosyn. slows or stops Enzymes control photosynth. and enzymes work within a range of temps (0-35°)

7. What affects photosynthesis? Intensity Light intensity up, rate up Only to a point, then no more

Ta-da….you have covered photosynthesis!