1. Cellular Respiration!

2. C6H12O6 + 6O2 Enzymes 6CO2 + 6H2O + energy
What do living things do with food?
Produce materials that bodies need to grow
Materials can be converted to energy
C6H12O6 + 6O2 Enzymes 6CO2 + 6H2O + energy

3. How do living things release energy from food??
Cellular respiration!
Begins with glycolysis
break down glucose  pyruvic acid
small amount energy released (ATP)

4. Overview
No oxygen
Fermentation
Lactic Acid Alcoholic

6. Glycolysis (in cytoplasm)
Glucose (6C) split into:
2 pyruvic acid (3C)
Result: 2 ATP & 2 NADH
**4ATP formed, 2 used → net gain = 2ATP

7. Who uses glycolysis? ALL organisms!!!
Glycolysis does NOT require oxygen → small amts of energy formed without O2
As form ATP, available NAD+ decreases  decreases ATP synthesis of glycolysis

8. Fermentation! Two Types NADH converted to NAD+
Anaerobic respiration - does not require O2
Two Types
Lactic Acid
Alcoholic

9. What do these items have to do with fermentation?

10. 1. Lactic acid fermentation
Pyruvic acid converted to lactic acid
Lactic acid forming microorganisms used in making foods (Ex: yogurt, cheese, sour cream)
Lactic acid build up in muscles causes cramps

11. 1. Alcoholic fermentation
Pyruvic acid converted to CO2 and ethyl alcohol
Basis for wine and beer industry; bread

12. Efficiency of anaerobic respiration
Glycolysis produces how many ATP molecules?
TWO
This is ~2% energy in glucose
Can any organisms survive on fermentation alone???

13. Aerobic Respiration
No oxygen
Fermentation
Lactic Acid Alcoholic

14. Electron transport chain
Aerobic respiration
Energy in pyruvic acid released using oxygen
Produces 20x more ATP than glycolysis!
2 major stages
Krebs cycle
Electron transport chain

15. Where does respiration occur?
Prokaryotes
Respiration occurs in cytosol
Anaerobic or aerobic?
Eukaryotes
Kreb cycle and ETC occur in mitochondria

17. A little about the mitochondria…
1. Pyruvic acid diffuses across membrane, enters matrix
Matrix – contains enzymes used in Krebs cycle
2. Pyruvic acid reacts with Coenzyme A to form acetyl CoA (produces 2 NADH)
Pyruvic Acid (C-C-C)
Coenzyme A
Acetyl CoA (C-C)

19. Part I. The Krebs Cycle
Overview: energy molecules & waste products formed as Acetyl CoA broken down
Acetyl CoA forms citric acid
CO2 molecules are released
**NADH, FADH2, ATP formed

20. Energy Tally Glycolysis – 2 ATP 2 NADH
Conversion to – 2 NADH Acetyl CoA
Krebs cycle – 2 ATP NADH 2 FADH energy molecules to next stage

22. Part II. Electron Transport Chain
Embedded in inner membrane of mitochondria
Water released as waste byproduct
High energy electrons converted to ATP
Each NADH forms 3 ATP FADH2 forms 2 ATP

24. Energy Conversion Glycolysis – 2 NADH
**The Rules: NADH = 3 ATP FADH2 = 2 ATP
Glycolysis – 2 NADH
Conversion to – 2 NADH Acetyl CoA
Krebs cycle - 6 NADH FADH2
ETC
_____ ATP
_____ ATP
____ ATP ____ ATP
+ 4 ATP =
**TOTAL ATP Molecules: ____**
____ ATP?