1. Photosynthesis and Cellular Respiration

2. How do cells obtain organic compounds for energy?
Heterotrophs: Cannot make their own food
Autotrophs: Can make their own food
Photoautotrophs: Use energy from the sun (photosynthesis) to produce organic compounds (glucose)
Plants, protists and some bacteria
Chemoautotrophs: Use energy stored in inorganic compounds (chemosynthesis) to produce organic compounds
Some bacteria found at the hydrothermal vents of the seafloor

3. Photosynthesis
Method of converting light energy from the sun into chemical energy that cells can use
Divided into the light-dependent and light-independent reactions
Photosynthesis takes place in chloroplasts
The parts of a chloroplast are as follows:
Thylakoids- disk-shaped structures that contain the pigment chlorophyll (absorbs the sunlight)
Grana- Stacks of thylakoids
Stroma- Liquid between grana

4. Draw a Chloroplast

5. Overall Photosynthesis Reaction
6CO2 + 6 H2O + light energy → C6H12O6 + 6O2
On the left of the arrow are the reactants (the components that “react” together).
On the right of the arrow are the products.
Identify how a plant obtains the reactants.

6. Photosynthesis Practice
You need the following:
6 orange circles = C
12 blue triangles = H
18 red squares = O
1 large green oval = thylakoid
1 purple rectangle = ATP
1 brown rectangle = NADPH
1 yellow star = sun 

7. Light-dependent Reactions
Chlorophyll (in thylakoids) absorbs the light energy
Plants have 2 types: Chlorophyll A and Chlorophyll B
Water molecules are split apart producing H and O2
Electrons flow throughout the thylakoid membrane (electron transport chain)
Energy compounds ATP and NADPH are produced

9. Light-independent Reactions (Dark Reactions)
Occur in the stroma
ATP and NADPH (Nicotinamide adenine dinucleotide phosphate) from the light reactions are used to fuel the break down of CO2 and the reassembling of the atoms to produce glucose.
This reassembling is called “carbon fixation”.
Carbon fixation occurs in a series of reactions called the Calvin Cycle.

12. Getting energy out of food
Plants and animals both use glucose from photosynthesis for cell fuel.
Glucose (or other carbs), proteins, and fats are not a form of energy that our cells can use.
Cellular respiration converts glucose into a usable energy form (ATP) for cells.
Interesting Fact: One human cell consumes approximately 173,000,000 ATP per minute!

13. Cellular Respiration Overview
The reactions of cellular respiration occur the same way in plants and animals.
Overall Reaction:
C6H12O6 + 6O2 → 6CO2 + 6H2O + 36 ATP
How is this compared to the photosynthesis equation?

14. Glycolysis Glycolysis is the first process of cellular respiration.
It occurs in the cytosol.
Glucose (C6H12O6) is partially broken down to produce 2 pyruvate (C3H3O3) compounds
This process yields 2 ATP and 2 NADH for every glucose molecule.

16. Aerobic Cellular Respiration
Oxygen required=aerobic
Aerobic respiration follows glycolysis.
It occurs in the mitochondria.
There are 2 main parts to aerobic respiration:
Kreb’s Cycle
Electron Transport Chain

17. Kreb’s Cycle Completes the breakdown of glucose
Takes the 2 pyruvate (C3H3O3) and completely breaks them down.
The carbon and oxygen atoms of pyruvates end up in CO2 and H2O
This is where the CO2 that we exhale is produced!
3 NADH and 1 FADH2 and 2 ATP get produced

18. Electron Transport Chain
Here is where most of the energy is produced!
Electron flow ultimately produces 32 ATP!
The oxygen that we inhale is the electron acceptor at the end of the ETC. This acceptance of electrons is what produces the ATP.

20. Cellular Respiration

22. Cellular Respiration Practice
You and a partner need:
5 yellow rectangles- NADH
4 red rectangles- ATP
1 red rectangle- 32 ATP
1 purple rectangle- FADH2
1 blue oval- mitochondrion
1 green circle- O2

23. Anaerobic Cellular Respiration (Fermentation)
Some organisms (some bacteria) thrive in environments with little or no oxygen
No oxygen used= anaerobic
Anaerobic organisms experience anaerobic cellular respiration after glycolysis.
This produces CO2 and NO ATP!
Depending on the type of cell, the end products of this are alcohol or lactic acid.

25. Energy Tally (ATP)
Anaerobic organisms can’t be too energetic but are important for global recycling of carbon
Aerobic
Anaerobic
Glycolysis
Kreb’s Cycle
Electron Transport Chain
Total ATP per glucose