1. Chapter 9
Cellular Respiration
Production of ATP
Pages:

2. Main Topics Anaerobic Respiration vs Aerobic Respiration
Glycolysis & Fermentation (Anaerobic)
Formation of Acetyl Coenzyme A
Citric Acid Cycle (Kreb cycle)
Electron Transport Chain & Chemiosmosis

3. Introductory Questions #8
How does aerobic and anaerobic respiration differ?
What are the four main stages of aerobic Respiration?
Write the chemical equation for cellular respiration.
How can you tell which one is oxidized and what is reduced?
Within a Eukaryotic cell, where does glycolysis take place? What about the citric acid cycle?
List the ten enzymes needed for each conversion in the glycolytic process. (pg )
What do Kinase enzymes do?

4. Introductory Questions #9
Name the two enzymes that are responsible for making ATP via substrate level phosphorylation during glycolysis. Which Enzyme splits the sugar molecule in the first part of glycolysis?
What is so special about a Facultative Anaerobe? Give an example of one. Define what a strict and obligate anaerobe are?
What is the main purpose of fermentation?
Explain how alcoholic fermentation is different from lactic acid fermentation.
What are two fates of Pyruvic acid?

5. Two Types of Respirations
Anaerobic:
-Most primative metabolic pathway
-Produces two ATP’s per molecule of glucose
-Main pathway in prokaryotic cell (bacteria)
-Final electron acceptor is an inorganic molecule (nitrate or sulfate)
Fermentation
Aerobic:
-Requires molecular oxygen (O2) = final electron acceptor
-Produces up to 38 ATP’s per glucose molecule
-Occurs in Eukaryotic cells within the mitochondria
-Most common metabolic pathway

6. Pyruvate → Acetyl Coenzyme A
Aerobic Respiration
C6H12O6 + 6O2  6 H2O + 6 CO2 + Energy
G = -686 kcal ( kJ)
One ATP molecule has a G of -7.6 kcal/mol
C6H12O6 – Oxidized O2 – Reduced
Begins with:
Pyruvate will be oxidized as it enters into the mitochondria
to form Acetyl Coenzyme A. NADH is also produced.
Pyruvate → Acetyl Coenzyme A

7. Efficiency of Cellular Respiration

8. Two methods of Producing ATP
Substrate Level Phosphorylation (SLP)
-Simplest way to make ATP
-Requires no membrane
-Uses a large enzyme: Kinase
-Present in Anaerobic Respiration
Chemiosmosis
-Discovered by Peter Mitchell (1978)
-Aerobic Respiration (mitochondria)
-Requires a “Proton gradient” to be generated

9. Substrate Level Phosphorylation & Chemiosmosis
Kinase

10. Redox Nature of Cellular Respiration
Oxidizing agent
Reducing Agent

11. Overview of Aerobic Respiration in Eukaryotic Cells

12. Four Stages of Respiration
Glycolysis & Fermentation (SLP)
Formation of Acetyl Coenzyme A
Citric Acid Cycle (Kreb Cycle)
Electron Transport Chain (Chemiosmosis)

13. Glycolysis Literally means “sugar-splitting”
First metabolic pathway to evolve
Does not require oxygen
Can occur under anaerobic or aerobic respiration
Observed in all cells
Occurs in the cytosol (cytoplasm) of the cell
Net profit of two ATP molecules via SLP

14. Key molecules of Glycolysis
Start with: One molecule Glucose (six carbons)
Two molecules of ATP
Two molecules of NAD+
Two ADP and inorganic phosphates
Enzymes for each step
Dehydrogenase (for SLP)
End with: Two Pyruvate molecules (three carbons each)
Two ATP molecules (net)
Two NADH molecules

15. Glycolysis: Overview

16. First Phase of Glycolysis-Use of 2 ATP’s
Enzymes you need to know
1. hexokinase
(1st ATP phosphorylates glucose)
2. Phosphoglucoisomerase
(glucose into fructose)
3. phosphofructokinase
(2nd ATP phosphorylates fructose)
4. aldolase
(splits fructose into
two 3 carbon sugars)
DHAP
5. isomerase
(converts Dihydroxyacetone
(DHAP)into G3P)

17. Summary of First Phase of Glycolysis
Glucose ↓
Fructose 1,6 Bisphosphate
Glyceraldehyde-3-phosphate (x2)
Enzymes involved:
Phosphoglucoisomerase Hexokinase Phosphofructokinase Isomerase
Aldolase
**Put them in sequential order
**What happens next?

18. NAD+ and NADH (pg. 163)
Two e’s and one H+ are gained

19. Second Phase of Glycolysis-Energy Payoff
Enzymes you need to know
6. Dehydrogenase Enzyme
NAD+ (hydrogen acceptor from G3P)
7. Phosphoglycerokinase
ADP to ATP via SLP
8. Phosphoglyceromutase
(rearrangement)
9. (Enolase)
10. (Pyruvate Kinase)
ADP to ATP via SLP

20. Summary of Chemical Changes-2nd Phase
Glyceraldehyde-3-phosphate (x2)
↓ Enzyme #6
Phosphoglycerate (NAD+----NADH) ↓
1,3-bisphosphoglycerate
↓ Enzyme #7
3-Phosphoglycerate
↓ Enzyme #8
2-phosphoglycerate
↓ Enzyme #9
Phosphoenolpyruvate (PEP)
↓ Enzyme #10
Pyruvate

21. Glycolysis end result End Result:
4 ATP’s made Two used initially (net = 2)
2 Pyruvate molecules (3 carbons)
2 NADH ‘s made
2 water molecules released

22. Overall Energetics of Glycolysis