1. 4.4 Overview of Cellular Respiration

2. Cellular Respiration…
Is a process that makes ATP by breaking down sugars (glucose).
Cellular respiration is aerobic, or requires oxygen.
Three Stages:
Glycolysis
Krebs Cycle
Electron Transport Chain

3. Cellular respiration takes place in the mitochondria!!!

4. Step 1: GLYCOLYSIS
MUST happen FIRST…REQUIRED for Cellular Respiration.
Anaerobic process (does NOT require oxygen)
Takes place in cytoplasm
Enzymes split glucose into two three-carbon molecules
Pyruvic Acid
Produces two ATP molecules

5. Step 2: The Krebs Cycle
Is the first main part of cellular respiration.
Produces molecules that carry energy to the second part of cellular respiration.

6. Stage 2: KREBS CYCLE (Aerobic Pathway)
takes place in the matrix of the mitochondria
breaks down three-carbon molecules from glycolysis (Pyruvic Acid molecules)
Regulated by enzymes
Makes 2 molecules of ATP
Releases carbon dioxide
Transfers energy-carrying molecules to Electron Transport Chain
NADH & FADH2

7. energy from glycolysis
6H O 2
6CO 6O
mitochondrion
matrix (area enclosed
by inner membrane)
inner membrane
ATP
energy
energy from glycolysis 4 3
and

8. Step 3: The Electron Transport Chain
Second main part of Cellular Respiration
takes place in the inner membrane of the mitochondria
Uses energy from Krebs Cycle to drive electron transport chain
Oxygen enters process
32-34 molecules of ATP produced
water released as a waste product
Formed when enzyme combines hydrogen and oxygen

9. energy 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

10. Products of Cellular Respiration-including Glycolysis
6 molecules Carbon dioxide from the Krebs cycle and Glycolysis
6 molecules of water from the electron transport chain
A net gain of up to 38 ATP molecules for every glucose molecule
2 from glycolysis
2 from the Krebs cycle
32-34 from the electron transport chain

11. Glucose + Oxygen  Carbon dioxide + Water + Energy
The equation for the overall process of Cellular Respiration is:
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
Glucose + Oxygen  Carbon dioxide + Water + Energy

12. Relationship between Photosynthesis & Cellular Respiration:
The reactants in photosynthesis are the same as the products of cellular respiration.

13. Cellular Respiration