1. Cellular Respiration Overview
Cellular Respiration song to the tune of Californication =)
..\..\Biology 11-12\Bio videos\Cellular Respiration.mp4

2. Cellular Respiration Organic Compounds Oxygen Water Energy + CO2 + +
Aerobic Cellular Respiration occurs in the presence of oxygen in the cytosol and the mitochondria
The process can be summarized as:
C6H12O6 + 6O2  6CO2 + 6H2O + Energy (ATP and Heat)
Organic
Compounds
Oxygen
Water
Energy +
CO2 + +

3. Redox Reaction
Redox Reactions – Reactions involving the transfer of electrons
Oxidation – When a substance loses electrons in a redox reaction
The substance accepting the electron is known as the oxidizing agent
Reduction – When a substance gains electrons in a redox reaction
The substance donating the electron is known as the reducing agent

4. Example: Sodium Chloride
Becomes Oxidized (loses electron)
Oxidizing
Agent + Na Cl - Na Cl + +
Reducing
Agent
Becomes Reduced (gains electron)

5. Production of ATP C6H12O6 6O2 6CO2 6H2O + + + Energy Becomes Oxidized
Oxidizing
Agent
C6H12O6
6O2
6CO2
6H2O + + +
Energy
Reducing
Agent
Becomes Reduced

6. Overview of the Process
With oxygen present, there are 3 main steps in cellular respiration:
Glycolysis
The Citric Acid Cycle (Krebs Cycle)
Oxidative Phosphorylation
ETC
chemiosmosis

7. Citric Acid Cycle ATP ATP ATP Glycolysis Oxidative Phosphorylation:
NADH
NADH and FADH2
Oxidative
Phosphorylation:
ETC
And
Chemiosmosis
Citric
Acid
Cycle
Glycolysis
Glucose
Pyruvate
ATP
ATP
ATP

8. Types of Phosphorylation
Phosphorylation is how ATPs are formed
Oxidative Phosphorylation – Phosphates added to ADP via the redox reactions in the ETC
Substrate Level Phosphorylation – An enzyme transfers a phosphate from a substrate, to ADP (glycolysis and citric acid cycle)

9. Glycolysis Glyco=Sugar; Lysis= Split
In Gylcolysis, Glucose is split into two 3-carbon pyruvate (pyruvic acid) molecules
In order to begin, glycolysis requires the input of energy (ATP)
Glycolysis occurs in the cytosol
Lets look at Glycolysis in a very simple form:

10. Glycolysis (Simplified)
2 ATP are added in the presences of glucose
2 NADH are produced
4 ATP are produced (Net gain of 2)
2 Pyruvate molecules are formed

11. 4 ADP 2 ADP 2ATP Glucose 4ATP 2 NADH Pyruvic Acid 2 NAD+ C C C C C C C

12. Citric Acid Cycle Also referred to as the Krebs Cycle
Takes place in the matrix
When oxygen is present, the Citric Acid Cycle follows Glycolysis
This cycle takes pyruvate from glycolysis to make ATP, NADH, and FADH2

13. Citric Acid Cycle Simplified
Pyruvate turns into acetyl CoA via coenzyme A (CoA) (this is the link between glycolysis and the Citric Acid Cycle)
Acetyl CoA enters the Citric Acid Cycle and is then transformed into citrate
There are 7 intermediate molecules, until Oxaloacetate is reformed to begin the cycle again

15. Citric Acid Cycle - Products
3 NADH, 1 FADH2, 1ATP, and CO2 are produced in the Citric Acid Cycle
Each NADH will generate about 3 ATP
FADH2 will generate about 2 ATP
The CO2 released from this cycle is the same CO2 that you exhale while breathing

16. Oxidative Phosphorylation
This is the process of extracting ATP form the energy in NADH and FADH2
Occurs in the cristae of the mitochondria
The electrons are passed through an ETC to release ATP
The final electron acceptor is oxygen
Oxygen bonds with 2 electrons (carried by Hydrogen) to produce water

17. e-
ADP
ATP
ADP
ATP
ADP
ATP
Energy Level
ADP
ATP H O

18. Totals
+2 ATP ATP ATP = 36 ATP
ETC
Glycolysis
Krebs
Cycle

19. Anaerobic Environments
When no oxygen is present, the cell will have to do one of two things:
Die due to the fact that there is no Oxygen to accept electrons at the end of oxidative, so no more NAD+ are made or
They can undergo Fermentation:
Lactic Acid
Alcoholic

20. Fermentation Takes place in the mitochondrial inner membrane
Does not require oxygen to occur
Does not directly produce ATP

21. Lactic Acid Fermentation
Pyruvate comes from glycolysis and is turned into lactate (lactic acid)
NADH gives an electron to become NAD+

22. Alcoholic Fermentation
Pyruvate comes from glycolysis, and is changed into acetaldehyde, and a CO2 is given off in the process
Acetaldehyde is turned into ethanol with the help of an electron from NADH
The products are CO2, Ethanol, and NAD+

23. Why fermentation? Why do cells switch to fermentation?
Why can’t cells use glycolysis and the Krebs cycle in an anaerobic environment?
Right now with your table compare and contrast aerobic and anaerobic respiration

24. Begin work on dynamic models
Work with the group you are assigned
Read through the assignment
Design your model
Divide up the work
And begin!
Oh, and be ready for a short quiz tomorrow on the overview of cellular respiration.

25. Cellular Respiration – A Review of the Process
Test your knowledge and complete the graphic organizer without looking at your notes/book/etc.!
Work independently =)
You have 10 minutes, turn in to the HW folder when done. We will correct in class.

26. Glycolysis Breaks down glucose into pyruvic acid 2 ATP are added
2 NADH are produced by NAD+ accepting 2 electrons
4 ATP are produced (yielding a net gain of 2 ATP)
2 Pyruvic acid molecules are formed
**There are 9 intermediate molecules between glucose and pyruvate**

27. Krebs Cycle (Citric Acid Cycle)
Before the actual cycle begins, pyruvate combines with coenzyme A (CoA) to produce a molecule called acetyl CoA
1 NADH and 1 CO2 is produced
The first actual step of the Krebs Cycle is when oxaloacetate combines with acetyl CoA to make citric acid
Products: 3 NADH, 1 FADH2, 1 ATP 2CO2 (this is the CO2 that we exhale)

28. Oxidative Phosphorylation
The process of extracting ATP from NADH and FADH2
Electrons from the carriers are passed down an ETC
The electrons final acceptor is an Oxygen molecule, and water is formed as a byproduct
NADH can produce 3 ATP
FADH2 can produce 2 ATP

29. Chemiosmotic Phosphorylation
When the electrons lose energy in O.P. it is used for chemiosmotic phosphorylation
As the carriers move through the ETC, H+ are pumped from the matrix, across the cristae, and into the outer compartment creating a proton gradient (Potential Energy Reservoir)
Channel proteins (ATP Synthase) in the cristae allow the protons to flow through and use the energy to produce ATP from ADP

31. 2 Types of Phosphorylation
Substrate Level – Occurs when a phosphate group and its energy is transferred to ADP to form ATP. The substrate molecule donates the phosphate (occurs in glycolysis)
Oxidative Phosphorylation – Occurs when phosphate is transferred but not the energy. Energy is provided from electrons in the ETC

32. Alcoholic Fermentation
Pyruvic Acid is converted into acetaldehyde
1 CO2 and 1 acetaldehyde is produced
Acetaldehyde is converted into ethanol
1 ethanol is produced, and 1 NAD+ is produce
The entire point of this process is to send NAD+ back to glycolysis to keep slowly producing ATP

33. Lactic Acid Fermentation
Pyruvic Acid is converted to lactic acid
NAD+ is given off and sent back to glycolysis

34. Energy and Exercise

35. Energy in Humans What sort of activities cause you to use more energy?
Lets look at running

36. Human Body The human body has a limited amount of ATP stored in it
The reserve can last about 90 seconds of intense exercise (like sprinting)
What does this mean?

37. Intense Exercise Your body has 3 sources of ATP
Stored ATP
ATP’s from fermentation
ATP’s from cellular respiration
The stored ATP will only last about seconds
After that we begin to undergo lactic acid fermentation

38. Lactic Acid Fermentation
We can use the ATP’s in lactic acid fermentation for about 90 seconds
What builds up in our muscles when this happens?
Lactic Acid
The only way to break down and get rid of lactic acid is by using oxygen

39. Post Sprint Why do runners breath heavily after a race?
Runners breathe heavily after a race to get oxygen to our muscles to break down lactic acid

40. Running a Mile
We have just said that we can only generate ATP with lactic acid fermentation for about 90 seconds.
What if you were running a mile?

41. Long Term Energy
Lactic Acid releases energy very quickly (but can only last a short time)
When running a mile or more, your body will switch over to cellular respiration (instead of fermentation)
Cellular respiration releases energy much more slowly
This is why athletes must pace themselves during a race

42. Energy Sources
The body stores energy in a carbohydrate known as glycogen
After minutes of physical activity, the body will use other sources for energy
Fats
Proteins