1. Notes: Cellular Respiration Chapter 4 section 4.4; 4.5 and 4.6

2. Chemical energy and food
How much energy is in food?
When 1 gram of glucose (C6H12O6) is burned in the presence of oxygen, 3811 calories are released.
What is a calorie?
A calorie is the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius.

3. Chemical energy and food
On a food label Calories (with a capital “C”) represent kilocalories. 1 kilocalorie = 1000 calories.
Cells use the energy in glucose by slowly releasing it.

4. Chemical energy and food
How many calories are in 2 crackers?
How many calories are in 6 crackers?
60,000
180,000

5. Cellular Respiration is the SLOW release of energy from glucose.

6. Cellular respiration makes ATP by breaking down sugars.
Cellular respiration is aerobic, or requires oxygen.
Aerobic stages take place in mitochondria.
mitochondrion
animal cell

7. Overview of Cellular Respiration
Is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen within the mitochondria.
Oxygen + glucose  carbon dioxide + water + energy
O C6H12O6  CO H2O ATP

8. Glycolysis (part 1)
Glycolysis is the process by which one molecule of glucose is broken in half to produce two 3-carbon molecules of pyruvate (sometimes called pyruvic acid).
Occurs within the cytoplasm.

9. Glycolysis is needed for cellular respiration.
The products of glycolysis enter cellular respiration when oxygen is available.
two ATP molecules are used to split glucose
four ATP molecules are produced
two molecules of NADH produced
two molecules of pyruvate produced

10. Glycolysis must take place first.
anaerobic process (does not require oxygen)
takes place in cytoplasm
splits glucose into two three-carbon molecules
produces two ATP molecules and 2 NADH (NET)

11. Aerobic Cellular Respiration If Oxygen is present
The remaining 90% of the energy from the glucose molecule that was not used in glycolysis is used in the part of cellular respiration that requires oxygen (aerobic).
Cell Respiration occurs within the mitochondria when oxygen is present.
Also named aerobic respiration.
There are two parts after glycolysis: the Krebs Cycle and the Electron Transport Chain.

12. Cellular respiration is like a mirror image of photosynthesis.
The Krebs cycle transfers energy to an electron transport chain.
takes place in mitochondrial matrix
breaks down three-carbon molecules from glycolysis
6H O 2
6CO 6O
mitochondrion
matrix (area enclosed
by inner membrane)
inner membrane
ATP
energy
energy from glycolysis 1 4 3
and
Krebs Cycle
makes a small amount of ATP
releases carbon dioxide
transfers energy-carrying molecules

13. The Krebs Cycle
Krebs Cycle (Citric Acid Cycle)- Pyruvate is broken down into carbon dioxide molecules in a series of steps that also form ATP, NADH, and FADH2 for use in the Electron Transport Chain.
Occurs within the matrix
Play until 1:20

14. The Krebs cycle is the first main part of cellular respiration.
Pyruvate is broken down before the Krebs cycle.
carbon dioxide released
NADH produced
coenzyme A (CoA) bonds to two-carbon molecule

15. The Krebs cycle produces energy-carrying molecules.

16. The Krebs cycle produces energy-carrying molecules.
NADH and FADH2 are made
intermediate molecule with CoA enters Krebs cycle
citric acid (six-carbon molecule) is formed
citric acid is broken down, carbon dioxide is released, and NADH is made
five-carbon molecule is broken down, carbon dioxide is released, NADH and ATP are made
four-carbon molecule is rearranged

17. energy from glycolysis
The electron transport chain produces a large amount of ATP.
takes place in inner membrane
energy transferred to electron transport chain
oxygen enters process
ATP produced
6H O 2
6CO 6O
mitochondrion
matrix (area enclosed
by inner membrane)
inner membrane
ATP
energy
energy from glycolysis 1 4 3
and
Electron Transport
water released as a waste product

18. In the Electron Transport Chain,
Electron Transport Chain- Uses high energy electrons from NADH and FADH2 from Krebs cycle to build up H+ ions in the Intermembrane space making it positive and the matrix negative.

19. The electron transport chain is the second main part of cellular respiration.
The electron transport chain uses NADH and FADH2 to make ATP.
high-energy electrons enter electron transport chain
energy is used to transport hydrogen ions across the inner membrane
hydrogen ions flow through a channel in the membrane

20. The electron transport chain is the second main part of cellular respiration.
The electron transport chain uses NADH and FADH2 to make ATP.
The breakdown of one glucose molecule produces up to 38 molecules of ATP.
ATP synthase produces ATP
oxygen picks up electrons and hydrogen ions
water is released as a waste product

21. The equation for the overall process is:
C6H12O6 + 6O2  6CO2 + 6H2O
The reactants in photosynthesis are the same as the products of cellular respiration.

22. In the Electron Transport Chain,
The H+ ions will then move through the ATP synthase to the negative side causing the ATP synthase to turn. Each turn brings ADP and a phosphate (Pi) together to form high energy ATP.

23. The Krebs Cycle and Electron Transport Chain occur in the mitochondria.

24. Fermentation if no oxygen is present
Fermentation occurs when no oxygen is present.
Also called anaerobic respiration - meaning without oxygen.
It turns NADH back into NAD+ so that it can be recycled and glycolysis can continue.

25. Fermentation allows glycolysis to continue.
Fermentation allows glycolysis to continue making ATP when oxygen is unavailable.
Fermentation is an anaerobic process.
occurs when oxygen is not available for cellular respiration
does not produce ATP

26. Fermentation allows glycolysis to continue making ATP when oxygen is unavailable.
NAD+ is recycled to glycolysis
Lactic acid fermentation occurs in muscle cells.
glycolysis splits glucose into two pyruvate molecules
pyruvate and NADH enter fermentation
energy from NADH converts pyruvate into lactic acid
NADH is changed back into NAD+

27. pyruvic acid + NADH  lactic acid + NAD+
Lactic Acid fermentation- in a shortage of oxygen in your muscle cells, it regenerates NAD+ so glycolysis can continue.
Lactic acid builds up in your muscles which causes pain and soreness.
pyruvic acid + NADH  lactic acid + NAD+

28. Lactic acid fermentation also occurs with certain microorganisms to produce certain foods; Ex. yogurt, sour cream and pickles
yogurt
Sauerkraut 

29. Fermentation and its products are important in several ways.
Alcoholic fermentation is similar to lactic acid fermentation. Occurs in YEAST CELLS
glycolysis splits glucose and the products enter fermentation
energy from NADH is used to split pyruvate into an alcohol and carbon dioxide
NADH is changed back into NAD+
NAD+ is recycled to glycolysis

30. Two Types of Fermentation:
Alcoholic fermentation- Performed by yeast and other microorganisms
pyruvic acid + NADH  alcohol + CO2 + NAD+

31. We can use this to help us make things such as bread and wine

32. The Totals Cellular respiration produces 36 ATP molecules.
More ATP is produced with oxygen than without. Cellular respiration is more efficient using oxygen. 2 2 32

33. The Totals Glycolysis: 2 ATP
Fermentation: None! but regenerates electron carriers for glycolysis
Krebs Cycle: 2 ATPs
Electron Transport Chain: 32 ATPs

34. Total Number of ATP produced:
Anaerobic respiration: 2 ATP (From glycolysis)
Aerobic respiration: 36 ATP (From glycolysis, kreb’s cycle and electron transport chain)

35. Energy and Exercise: Quick Energy
Running a short race, you use ATP in your muscles, and produce new ATP by lactic acid fermentation and cellular respiration.
When sprinting, you produce most of your ATP using lactic acid fermentation because you have run out of oxygen for the Krebs cycle.
You breathe heavily after you finish a race to rebuild your ATP supply.

36. Energy and Exercise: Long-term Energy
When running a long race, you use carbohydrate energy stored as glycogen from your muscles and other tissues. This will give you enough energy for up to 20 minutes of activity.
After using up glycogen, your body will use up fats for energy.
Aerobic exercises like running and swimming are beneficial for weight control.

37. REVIEW

38. Comparing Photosynthesis and Cellular Respiration
If storing energy is compared to money in a savings account, photosynthesis deposits the energy and cellular respiration withdraws the money.
Cellular Respiration is the reverse reaction of photosynthesis.

39. What is the formula for photosynthesis?
6CO H2O + light  6O C6H12O6
What is the formula for cellular respiration (think about the opposite)?
6O C6H12O6  6CO H2O + ATP

40. Photosynthesis uses CO2 in the atmosphere, but cellular respiration puts it back
Photosynthesis releases O2 into the atmosphere but cellular respiration using O2 to release energy from the food
Cellular respiration occurs in all eukaryotes and some prokaryotes
Photosynthesis occurs only in plants, algae, and some bacteria. Other organisms (heterotrophs) get their food by consuming other organisms.

41. Which path produces the most ATP?
Where does glycolysis take place?
What phrase means without oxygen?
What phrase means with oxygen?
Where does the Krebs Cycle take place? 41

42. Which path produces the most ATP?
Where does the Electron Transport Chain take place?
What is the NET ATP for anaerobic respiration?
What is the NET ATP for aerobic respiration?
Which path produces the most ATP? 42