1. KEY CONCEPT
The overall process of cellular respiration converts sugar into ATP using oxygen.
Cellular respiration is an aerobic process with two main stages.

2. Cellular respiration makes ATP by breaking down sugars.
Cellular respiration is aerobic, or requires oxygen.
Aerobic stages take place in mitochondria.
mitochondrion
animal cell

3. The equation for the overall process is:
C6H12O6 + 6O2  6CO2 + 6H2O
How could you compare the equation for cellular respiration to that of photosynthesis?

4. Glycolysis happens before respiration.
anaerobic process (does not require oxygen)
takes place in cytoplasm
splits glucose into two three-carbon molecules
produces two ATP molecules
The products of glycolysis enter cellular respiration when oxygen is available.

5. Cellular respiration is like a mirror image of photosynthesis.
Step 1: The Krebs cycle produces molecules that carry energy to the second part of cellular respiration
takes place in mitochondrial matrix
breaks down three-carbon molecules from glycolysis
6H O 2
6CO 6O
mitochondrion
matrix (area enclosed
by inner membrane)
inner membrane
ATP
energy
energy from glycolysis 1 4 3
and
Krebs Cycle
makes a small amount of ATP
releases carbon dioxide
transfers energy-carrying molecules

6. The Krebs cycle is the first main part of cellular respiration.
Pyruvate is broken down, CO2 is released and NADH is produced
Coenzyme A (CoA) bonds to 2-C molecule

7. The Krebs cycle produces energy-carrying molecules.
3. Citric acid (6-C chain) is formed.
4. Citric acid is broken down, CO2 is released, and NADH is made.
5. 5-C chain is broken down, CO2 is released, and NADH & ATP is made.
6. 4-C chain is rearranged and NADH and FADH2 is made.
7. Krebs cycle

8. energy from glycolysis
Step 2: The electron transport chain produces a large amount of ATP.
takes place in inner membrane
energy transferred to electron transport chain
oxygen enters process
Most ATP produced here
6H O 2
6CO 6O
mitochondrion
matrix (area enclosed
by inner membrane)
inner membrane
ATP
energy
energy from glycolysis 1 4 3
and
Electron Transport
water released as a waste product

9. The electron transport chain is the second main part of cellular respiration.
The electron transport chain uses NADH and FADH2 to make ATP.
high-energy electrons removed from NADH and FADH2
H+ ions move across the membrane.
ADP turns into
ATP by use of the
ATP Synthase.
Water is made
from O, 2H+ & 2e-.

10. The electron transport chain is the second main part of cellular respiration.
The electron transport chain uses NADH and FADH2 to make ATP.
The breakdown of one glucose molecule produces up to 38 molecules of ATP.
2 – Glycolysis
2- Krebs cycle
34- Electron transport chain