1. Cellular Respiration Essential Questions:
How is the energy in our food released?
How does aerobic respiration and anaerobic respiration compare and contrast?
What are the 2 types of anaerobic respiration?
How are the processes of photosynthesis and cell respiration different?

2. Cellular Respiration
Cellular Respiration = Process by which mitochondria break down food molecules to produce ATP
Does not use Oxygen is called Anaerobic
Does use Oxygen is called Aerobic
There are 3 stages of Cellular Respiration:
1) Glycolysis (Anaerobic)
Citric Acid Cycle (Aerobic)
Electron Transport Chain
(Aerobic)

4. Glycolysis - Anaerobic
Glycolysis = series of chemical reactions in the cytoplasm of a cell that break down glucose (a 6 Carbon compound) into 2 molecules of pyruvic acid (a 3 Carbon compound)
NAD+ accepts a pair of high energy electrons to pass that energy to other pathways in the cell.
2 Molecules of ATP are used to start Glycolysis and only 4 ATPs are produced
Net only 2 ATP
Then pyruvic acid proceeds to the Mitochondria to begin the Citric Acid Cycle and the Electron Transport Chain (in the presence of Oxygen)

5. Anaerobic Processes
Sometimes your cells are without Oxygen for short periods of time (during strenuous exercise, etc)
In order to make ATP, the process of Fermentation occurs after Glycolysis until Oxygen becomes available again.
During fermentation, cells convert NADH to NAD+ by passing high energy electrons back to pyruvic acid. This action converts NADH back into the electron carrier NAD+ allowing glycolysis to continue producing a steady supply of ATP.
Some organisms simply live in areas without Oxygen and must produce their ATP this way.

6. 2 Anaerobic Processes: Lactic Acid Fermentation & Alcoholic Fermentation
Without Oxygen, the Electron Transport Chain becomes backed up since no Oxygen is there to be the final electron acceptor
Pyruvic Acid + NADH →
lactic acid + NAD+
Lactic Acid is the cause of sore muscles.
Certain organisms living in anaerobic environments will rely on this type of ATP synthesis.
Pyruvic acid + NADH →
alcohol + CO2 + NAD+
Yeast use this type of fermentation to create C02 and ethyl alcohol.

8. Aerobic Respiration Most efficient type of Cellular Respiration!
Requires Oxygen
Occurs in 3 steps:
1) Glycolysis
2) Citric Acid Cycle
3) Electron Transport Chain
Glycolysis is the only step that is Anaerobic.
The other Anaerobic process was fermentation.

9. Aerobic Respiration - Mitochondria
Remember, Glycolysis breaks down 1 glucose into 2 pyruvic acid molecules
Heads to Mitochondria for Aerobic Respiration
Citric Acid Cycle occurs in the outer mitochondrial membrane
Calvin Cycle – glucose was formed
Citric Acid Cycle – glucose is being broken down
For 1 Glucose molecule, 1 ATP is made for every turn of the cycle.

10. Electron Transport Chain 1:2
Very Similar to the ETC of the thylakoid in plants!
NADH and FADH2 pas energized electrons from protein to protein releasing small amounts of energy.
A Concentration gradient forms in the mitochondria
Hydrogen ions inside
Lack of Hydrogen ions outside
An Electrical gradient forms in the mitochondria (H+ ions pumped inside)
Positive in the center
Negative on the outside

11. Electron Transport Chain 2:2
What type of protein am I?
The final electron acceptor is Oxygen
Yields Carbon Dioxide (CO2), 2 Water, and 36 ATP
Most efficient process since anaerobic respiration only yields 2 ATP.
An Enzyme!

12. Overview of Cellular Respiration Label the picture on your notes!

14. Comparing Photosynthesis & Respiration
Food accumulated
Energy from the Sun stored in Glucose
CO2 taken in
Oxygen given off
Produces Glucose from PGAL
Goes on only in Light
Occurs in the presence of Chlorophyll of Plants only
Chloroplasts
RESPIRATION
Food Broken Down
Energy of Glucose Released
CO2 given off
Oxygen taken in
Produces Carbon Dioxide, Water & ATP
Goes on Day & Night
Occurs in all Living Cells (Plants and Animals)
Mitochondria