1. Sheriff Kubeka
201201410
Cellular respiration

2. Cellular Respiration
 When we eat, we get energy (glucose and
other sugars)
 Food energy is broken down into usable
energy
 Energy used to bond phosphate
groups to ADP to make ATP

3. Cellular Respiration
 What is cell respiration???
 Respiration: the process of breaking down
food molecules into usable energy
 THE GOAL:
 Create ATP for cells to use
 Free up electrons—have high energy

4. Cellular Respiration
2

5. Cellular Respiration

6. Cellular Respiration
 Types of cell respiration
 Aerobic Processes:
 REQUIRE oxygen to take place
 A lot of energy available (efficient)
 Anaerobic Processes:
 DO NOT require oxygen to take place
 Get energy quickly (inefficient)

7. Glycolysis
 Involves breaking down 6-carbon sugars
 Break sugars into pyruvic acid molecules
 3-Carbon molecules
 This process is ANAEROBIC
 No oxygen necessary
 Occurs in the cytoplasm of cells

8. Glycolysis
 You will need to know this…

9. Glycolysis
Just Kidding… 

10. Glycolysis
 Glycolysis also creates hydrogen ions
and free electrons
 The whole point of respiration = high energy
 H + ions bond with NAD+ to form
NADH + H +
 NADH carries electrons and H + ions
 This process uses 2ATP molecules and
creates 4 ATP molecules

12. Glycolysis
 TOTAL ATP PRODUCTION:
 Glycolysis Step 1 uses 2 ATP molecules
 Glycolysis Step 2 converts 4 ADP molecules
into 4 ATP molecules
 Net ATP production = 2 ATP for every
glucose molecule

13. Glycolysis

14. Glycolysis
 Oxygen is our friend…
 When oxygen is present,
aerobic respiration occurs
 Happens in the mitochondria

15. Glycolysis
 Breaking down Pyruvic Acid…
 Occurs in the mitochondria
 Pyruvic Acid = 3-carbon compound
 Broken down into…
 2-Carbon compound—acetic acid
 Carbon Dioxide

16. Glycolysis
 Intermediate Step in Glycolysis
 2-Carbon Compound—Acetic Acid
 Combined with coenzyme A (CoA)
 Forms compound called acetyl-CoA
 This is only an intermediate step—have to
move pyruvic acid into Krebs Cycle

17. Glycolysis
Glycolysis =
2 ATP

18. Citric Acid (Krebs) Cycle
 Produces more ATP and releases more
electrons
 Electrons picked up by NAD + and FAD
 Organic carrier molecules
 Occurs inside mitochondria
 Mitochondrial Matrix

19. Citric Acid (Krebs) Cycle
 Acetyl CoA combines with a 4-carbon
molecule to form a 6-carbon molecule
 Citric Acid
 Citric Acid broken down into a 5-carbon
compound
 NAD + removes electrons (NADH + H +)
 CO2 released

21. Citric Acid (Krebs) Cycle
 5-carbon compound broken down into a
4-carbon compound
 ATP created
 NAD + removes electrons (NADH + H +)
 CO2 released
 4-carbon compound (oxaloacetic acid) is
created
 Used to bond with acetyl- CoA to restart cycle

23. Citric Acid (Krebs) Cycle

24. Citric Acid Cycle =
2 ATP
Cellular respiration

25. Electron Transport Chain
 What is the ETC???
 A series of molecules along which electrons
are transferred, releasing energy
 Occurs in the mitochondria—
wall of mitochondria
 Aerobic process
 Oxygen is involved
 Acts as the electron acceptor

26. Electron Transport Chain
 As the electrons are passed between
carrier proteins, energy is released
 ATP is created
 Electrons are given up by the carrier
molecules
 NADH and FADH2 ------- NAD + and FAD

27. Electron Transport Chain

28. Electron Transport Chain
 As the electrons (H + ions) travel down
the chain, they bond with oxygen
 2 H + + 1 O = water (H2O)
 Electron acceptor
 Carbon is given off as carbon dioxide

29. Electron Transport Chain

30. Glycolysis
ETC =
34 ATP

31. Electron Transport Chain
 A problem exists if there is no oxygen
 Anaerobic process
 When oxygen is used up, electrons cannot
be removed
 Traffic jam in the mitochondria
 KEY POINT —Electron Transport Chain
cannot run without oxygen

32. Anaerobic Respiration
 If no oxygen present after glycolysis,
pyruvic acid can still be broken down
 Fermentation
2 ATP made during fermentation
 Uses electrons carried by NADH + H +
so that NAD+ can regenerate for
glycolysis

33. Anaerobic Respiration
 Two types of fermentation
 Lactic Acid Fermentation
 Alcoholic Fermentation
Glucose
2 Pyruvic
Acid
2 Lactic
Acid
Glucose
2 Pyruvic
Acid
2 Ethanol
+ 2 CO2

34. Anaerobic Respiration
 Lactic Acid Fermentation
NADH produce during glycolysis transfers H
atoms to pyruvate reducing it to lactate.
 Muscle fatigue
 When your muscle cells require more energy
than can be produced
 Lack of oxygen
 Lactic acid build up = muscle fatigue
 When oxygen is present, lactic acid breaks down

35. Anaerobic Respiration

37. Anaerobic Respiration
 Alcohol Fermentation
 Occurs in bacteria, plants and most animals
 Can you think of a bacteria that is used for
fermentation???
 Pyruvic Acid is converted into ethanol and
carbon dioxide

38.  Dacrboxylate pyruvate , releasing CO2 and
forming 2-C compound called
acetaldehyde.
 NADH produced during glycolysis transfers
hydrogen atoms to acetaldehyde, reducing
it to ethyl alcohol.
 Basis for the production of beer, wine, and
other alcoholic beverages.

39. Electron Transport chain
 Occurs in the inner membrane of the
mitochondrion.
 Energized electrons are carried by NADH
and FADH2 to the top of the chain.
 The electrons are passed from protein to
protein within the membrane, slowly
releasing their energy in steps. Some of
that energy is used directly to form ATP.

40. Anaerobic Respiration

41. Cellular Respiration
General Formula
C6H12O6 + 6 O2 6 CO2 + 6 H2O

42. Reference list
o Durana. Y . (2011) . Cellular respiration.
http://www.slideshare.net/yang286/cellula
r-respiration-9394052