1. Photosynthesis and Cellular Respiration

2. Two ways to get food “troph” = food Autotrophs Heterotrophs
Auto = self
Autotrophs make their own food
Heterotrophs
Hetero = different
Heterotrophs get their food from something else (they have to eat it)

3. Two ways to get food
Autotrophs
Plants
Heterotrophs
Animals

4. Photosynthesis

5. Photosynthesis
Converts the sun’s energy into chemical energy stored in sugar
Takes place in specialized structures inside plant cells called chloroplasts
Chlorophyll is the pigment that absorbs sunlight.

6. Photosynthesis Reaction
6CO2 + 6 H2O + light
energy → C6H12O6 + 6O2
The food plants make is called glucose (sugar)

7. Photosynthesis 2 different reactions Light Reactions Calvin Cycle
Capture light energy for photosynthesis
Calvin Cycle
Produces glucose sugar

10. Cellular Respiration
Cells
Breathing

11. Cellular Respiration Happens in both plant and animal cells
Overall Reaction:
C6H12O6 + 6O2 → 6CO2 + 6H2O

12. Cellular Respiration Overview
Depends on whether or not there is oxygen
Aero = oxygen
Aerobic Respiration – makes energy
Anaerobic Respiration – Fermentation (makes alcohol)

13. Step 1: Glycolysis The energy that cells make and use is called ATP
Adenosine triphosphate
Glycolysis makes 2 molecules of ATP (energy)
Glycolysis happens in the cytoplasm of the cell

14. Step 2: Check for Oxygen
If oxygen is present, the cell can make more ATP
If no oxygen is present, the cell has to recycle the pieces from glycolysis and makes alcohol.

16. Step 3 with oxygen: Cellular Respiration
Oxygen required=aerobic
2 more sets of reactions which occur the cell’s mitochondria
1. Kreb’s Cycle – makes 2 ATP
Also called the Citric Acid Cycle
2. Electron Transport Chain – makes ATP

17. Kreb’s Cycle (Citric Acid Cycle)

18. Step 3 without oxygen: Fermentation
The cell must recycle the materials from glycolysis.
This recycling process is called fermentation.
The product of fermentation is alcohol.

20. Energy Tally 36 ATP for aerobic vs. 2 ATP for anaerobic
Glycolysis ATP
Kreb’s ATP
Electron Transport 32 ATP
36 ATP
Anaerobic organisms can’t be too energetic but are important for global recycling of carbon