1. CELL RESPIRATION

2. RESPIRATION Two Meanings: BREATHING OR EXTERNAL RESPIRATION
CELLULAR RESPIRATION - Process by which organic compounds are broken down to yield energy for work
This energy molecule is _________

3. Overall Equation
Glucose + Oxygen ---> Carbon Dioxide + Water + Energy or
C6H12O6 + 6O2 ---> 6CO2 + 6H2O + (36-38)ATP

4. Why is Cellular respiration Important?
Two main reasons
ATP is made that allows cells to carry out all its activities
Carbon Dioxide produced is used by autotrophs for Photosynthesis

5. Where does Cellular respiration occur?
In all Living cells Prokaryotic cells - in cytoplasm and inner foldings of plasma membrane Eukaryotic cell – cytoplasm and mitochondria

6. What are the raw materials needed
Sugar (glucose)
Oxygen (not always)
Water

7. Aerobic - with oxygen, releases the most ATP per glucose molecule
TYPES OF RESPIRATION
Aerobic - with oxygen, releases the most ATP per glucose molecule
Anaerobic - without oxygen, releases the least ATP per glucose molecule

8. Info About Aerobic Respiration
Oxygen needed
Breakdown of glucose- occurs in cytoplasm
In mitochondria
Krebs cycle - in the matrix
Electron transport chain - in the cristae
6 carbon dioxide molecules formed
36-38 ATP molecules formed

9. Both Processes start with Glycolysis
Glyco stands for Glucose
Lysis means to Split
What is Glycolysis?

10. Glycolysis (occurs in the cytoplasm
Glucose
2 ATP
2 ADP+P
2 PGAL
4 ADP+P
2 NAD+
4 ATP
2 NADH
2 Pyruvate

11. What happens Glycolysis?
Occurs in the cytoplasm of all organisms.
6 Carbon Glucose splits into 2 molecules each containing 3 carbons (called pyruvate)
Because Glucose is a pretty stable molecule, energy is needed to start this reaction (2ATP)

12. What is Glycolysis? This process generates 4 ATP and 2 NADH
What is the net gain of ATP at the end of this reaction? 2

14. Krebs Cycle or Citric Acid Cycle
Hans Krebs ( Nobel Prize)
Pyruvate lysed through a series of steps to release all the carbon as Carbon dioxide.
How many carbon dioxide molecules are formed? ______
What else?
2 ATP
6 NADH (+2 in the intermediate)=8
2 FADH2 (similar molecule to NADH)

15. Let’s Take Inventory! So far (from Glycolysis to Krebs Cycle)
We have used 2 ATP
We have made 4 ATP in glycolysis
We have made 2 ATP in Krebs Cycle
Total gain of ATP __4
How many ATP molecules do you need per minute per cell? Is this enough?

16. From Wikipedia.org/wik/Electron_transport_chain

17. Electron Transport Chain (ETC)
Occurs on the mitochondrial inner membrane or cristae
NADH and FADH2 release their Hydrogen atoms
Hydrogen atoms breaks up into e- and H+
Electrons travel through the membrane proteins

18. Electron Transport Chain (ETC)
Hydrogen accumulate inside the cristae
Concentrations gradient drives the H+ through the ATP Synthase
Energy used to make ATP (32 ATP)
The hydrogen then reacts with the oxygen molecules to make H+ + O2 --> H2O
Some energy lost as heat – useful to keep warm

19. So How many ATPs are made
Glycolysis: Net gain of 2
Krebs Cycle: 2
ETC: 32-34
Note:
Each NADH can make 3 ATP
Each FADH2 can make 2 ATP
TOTAL = 36 ATP

20. Anaerobic Respiration
Absence of oxygen
Krebs Cycle and ETC cannot function
Glycolysis can occur
Cell gets 2 ATP per glucose
NADH builds up and will eventually stop
formation of ATP
Survival Tactics??

21. Anaerobic Respiration
Lactic acid fermentation
Alcoholic fermentation
Yeast helps bread rise
Yeast used to make alcoholic bevs
Used to make gasohol
Human muscle contract in low O2
In Bacteria to make cheese, yogurt, sauerkraut

22. 2 ATP made and NADH recycled Alcoholic fermentation

23. 2 ATP made and NADH recycled Lactic Acid Fermentation

24. Glucose 2pyruvate No oxygen needed (anaerobic) Many enzymes needed
4 ATPs needed, 2 ATPS made
net gain of 2 ATP
2NAD 2 NADH