1. Bell work 11/09
What are the 3 steps of aerobic respiration and what is their main function?

2. Cellular Respiration

3. Chemical energy and food
Calorie- the amount of energy need to raise the temperature of 1 gram of water 1 degree Celsius.
Ex: 1 g of glucose releases 3811 calories of heat energy
Kilocalorie (used on food labels)
Cells gradually release the energy from glucose and other food sources
Begins with glycolysis

4. Overview of cellular respiration
6O2 + C6H12O6  6CO2 + 6H2O + ENERGY
Glycolysis, the Krebs cycle, and the electron transport chain make up cellular respiration!
Main goal= make energy (in the form of ATP)

5. Glycolysis

6. Glycolysis
The process in which one molecule of glucose (a 6 carbon compound) is broken is half, producing 2 molecules of pyruvate (a 3 carbon compound)
If there is oxygen (aerobic) followed by the Krebs cycle and electron transport chain
If there isn’t oxygen (anaerobic) followed by fermentation

7. What is the net gain of ATP?
Glycolysis
Overall, ENERGY PRODUCING process
HOWEVER, it needs to put IN energy to get things going
2 molecules of ATP are used up
Analogy: Like an investment earning interest!
4 molecules of ATP are produced!
What is the net gain of ATP?
2 ATP molecules!

8. Glycolysis
After using energy to get things started and break 1 glucose into 2 pyruvate  glycolysis makes 4 ATP and removes 4 high energy electrons
Passes these electrons to electron carrier NAD+
Similar to NADP+ in Photosynthesis
NAD+  NADH (can hold 2 high-energy e-)
NADH takes those electrons to the Electron transport chain to make MORE energy (ATP)
- Actually broken into G3P but since that is not stable, it is converted into Pyruvate

9. Glycolysis SO… Glycolysis produces 2 molecules of ATP
2 molecules of NADH
PER molecule of glucose broken down

10. Glycolysis Energy yield from glycolysis is small but FAST!
Cells can produce thousands of ATP molecules in a few milliseconds
Glycolysis itself does not need oxygen so it can supply chemical energy to the cells when oxygen is not present
When glycolysis generates large amounts of ATP, NAD+ molecules are filled up with electrons. Without NAD+, the cell cannot keep glycolysis going and ATP production stops.

11. Anaerobic
If no oxygen is present (anaerobic followed by fermentation

12. Describe the process of glycolysis.
Bell work 1/4
Describe the process of glycolysis.

13. Yeast Lab

14. Yeast lab reflection What are the products of fermentation?
Is there evidence for each product?
How can we determine in this lab whether this was aerobic or anaerobic?
How is anaerobic different from aerobic respiration?

15. Yeast lab Explanation
Yeast is a facultative anaerobe, meaning that it can participate in aerobic respiration when possible, but when this is impossible, it respires anaerobically.
When using yeast in making dough, the yeast will use the initial oxygen up very quickly and then start to respire anaerobically. 
ATP will then be made via glycolysis, which requires no oxygen. 
To regenerate the NAD+, the yeast will undergo alcoholic fermentation, which converts pyruvic acid into CO2

16. Fermentation
Fermentation- releases energy from food molecules by producing ATP in the absence of oxygen
Cells convert NADH into NAD+ by passing high-energy electrons BACK to pyruvic acid more ATP production
ANAEROBIC meaning “not in air”
So like we said, Glycolysis is fast and doesn’t need oxygen, but if you go too long without oxygen, you start running out of NADH to use in glycolysis! That’s where fermentation comes in handy. It allows the speedy process of glycolysis to keep going by taking the electrons from NADH so it will be NAD+ again to be used in glycolysis. Fermentation is kind of like a locksmith. You want to use your money (NAD+) to buy things, but it is locked in a safe (NADH) and you cant get it. The locksmith opens your safe and lets you get to your money.

17. Fermentation Two main types: Alcoholic fermentation
Lactic acid fermentation

18. Alcoholic fermentation
Yeast uses alcoholic fermentation, forming (ethyl) alcohol and CO2 as waste
Causes bread dough to rise
When yeast in the dough runs out of oxygen, it begins to ferment, giving off bubbles of CO2 (forms the air spaces you see in bread)
The small amount of alcohol evaporates when the bread is baked.

19. Alcoholic Fermentation
Pyruvate + NADH  Alcohol + CO2 + NAD+

20. Lactic Acid fermentation
Converts pyruvate into lactic acid
Lactic acid is what builds up in your muscles when you exercise to make you sore!
Why??

21. Lactic Acid fermentation
Converts pyruvate into lactic acid
Lactic acid is what builds up in your muscles when our exercise to make you sore!
Why??
Not enough oxygen
Without oxygen, your body cannot produce all of the ATP required
No ATP= No Glycolysis!

22. Lactic acid fermentation
Cells convert NADH into NAD+ by passing high-energy electrons BACK to pyruvic acid more ATP production

23. Lactic acid fermentation
Pyruvate + NADH  Lactic acid + NAD+

24. Aerobic Respiration
In the presence of oxygen (aerobic) followed by the Krebs cycle and electron transport chain

25. Krebs Cycle
The process in which pyruvate is transported to the mitochondrial matrix and is converted into CO2
Also known as the “citric acid cycle” or “TCA cycle”

26. How many molecules of pyruvate are formed during glycolysis?
Krebs cycle
How many molecules of pyruvate are formed during glycolysis?

27. Krebs cycle 2!
Resulting in two “turns” of the Krebs cycle for each glucose molecule

28. Krebs cycle
Net yield
6 CO2 molecules
2 ATP
8 NADH

29. Every time you exhale, you release CO2 from the Krebs cycle!

30. Krebs cycle

31. Electron Transport Chain
Final step!
The point where most of the ATP is produced!
High-energy electrons and H+ ions from electron carriers (NAPDH) are used to convert ADP to ATP

32. Electron Transport Chain

33. Electron Transport Chain
Electrons move down the mitochondrial membrane from one protein to another
As NADH (and FADH2) release electrons, the energy carriers are converted back to NAD+ (and FAD)
The energy used to transport electrons down the chain is used to transport H+ ions across the membrane

34. Electron Transport Chain
H+ ions diffuse down their concentration gradient through ATP synthase  produce ATP
At the end of the ETC is an enzyme that combines these electrons with hydrogen ions
Last carrier= Oxygen
Protons and electrons are transferred to oxygen to form water

35. Electron Transport Chain
Overall, produces
32 ATP
How do glucose and ATP differ in the amount of energy they store?

36. Electron Transport Chain
Overall, produces
32 ATP
How do glucose and ATP differ in the amount of energy they store?
Glucose stores more energy
(yields ATP)

37. Electron Transport Chain