1. Cellular Respiration
Chapter 9

2. What you need to know!
The role of glycolysis in oxidizing glucose to two molecules of pyruvate.
The process that brings pyruvate from the cytosol into the mitochondria and introduces it into the citric acid cycle.
How the process of chemiosmosis utilizes the electrons from NADH and FADH2 to produce ATP.

3. Aerobic Cellular Respiration
Definition: harvesting chemical bond energy (covalent) stored in glucose molecules
Redox reaction that:
Reduces O2 to H2O
Oxidizes glucose to CO2
Animal and plant cells
Location: cytosol and mitochondria
e- taxis of cytoplasm and matrix are NAD, FAD
Rx: 6O2 + C6H12O6  6 CO2 + 6 H ATP

4. 3 Stages Glycolysis Krebs Cycle (Citric Acid Cycle)
Oxidative Phosphorylation (ETC)
In the presence of O2 most ATP are made via chemiosmosis gradients in the ETC
Some ATP are made through substrate level phosphorylation
Rx: ADP + P  ATP

5. Anatomy of a Mitochondrion

6. The Big Picture

7. 1. Glycolysis Location: cytoplasm
Breaking down glucose (C6) into 2 pyruvic acids (C3)
Needs 2 ATP as activation energy
Subsequent enzyme Rx’s produce 4 ATP via substrate level phosphorylation
Glucose (C6) is converted into 2 pyruvic acids (C3) with a net yield of 2ATP & 2 NADH
No O2 is needed

8. Preparatory Step in Mitochondria (directly before Krebs)
Both Pyruvic acids are turned into Acetyl CoA (C2) by:
The attachment of CoA, releases one carbon as CO2
Formation of 2 NADH

9. 2. Krebs Cycle (Citric Acid Cycle)
Location: mitochondria
Complete oxidation of Acetyl
Each cycle:
Removal of CoA from 1 Acetyl
Releasing 2 carbons as CO2
Production of 1 ATP via substrate level phosphorylation
Production of 3 NADH
Production of 1 FADH2

11. 3. Oxidative Phosphorylation
Location: inner membrane of mitochondria
Oxygen needed
2 phases:
Electron Transport Chain: rows of interconnected membrane bound proteins
Creation of H+ gradient
Final electron acceptor of aerobic cellular respiration is Oxygen
Chemiosmosis: ATP Synthase makes ATP
Uses H+ gradient

12. Electron Transport Chain
NADH and FADH2 deposit high energy electrons to the chain
NADH feeds e- in the ETC at a higher point than FADH2 thus e- from NADH pump more H+ which in turn produce more ATP
The e- moves down the chain of proteins
Energy from the e- is used to power the ETC which pumps H+ into the intermembrane space
e- are sucked out of the chain by Oxygen:
O + 2e- + 2H+  H2O

13. Chemiosmosis H+ are allowed back into the matrix by ATP Synthase
This electrical flow provides the energy necessary to bind P to ADP
ADP + P  ATP

14. Oxidative Phosphorylation

15. ATP Yield Glycolysis = 4 Kreb = 2 ETC = 34 Activiation Energy = -2
Total = 38 ATP

16. Cellular Suffocation Clogging of ETC due to absence of O2 = no ATP
e- have nowhere to go
Glycolysis and Krebs Cycle stop
Cyanide and carbon monoxide are poisonous gases because they clog the ETC

17. The Big Picture