Cellular Respiration, Molecular Biol.ppt

Molecular and Cellular BIology/ Biochemistry

1. Cellular Respiration

2. Cellular Respiration
=the release of energy stored in food
=the released energy is stored short-term in
molecules of ATP (Adenosine Triphosphate)
Ribose
Adenine
Phosphates

3. Stored Energy
Energy Released
Adding Phosphates=phosphorylation
Energy had been used

4. The breakdown of glucose results in the
formation of many ATPs

5. How do we breakdown glucose?

6. Cellular Respiration
•Aerobic Cellular Respiration (Eukaryotes)

7. Cellular Respiration
•Anaerobic Respiration (Prokaryotes)
Glucose
Lactic Acid or Ethyl
Alcohol and CO
2
+2ATP

8. How do you pull apart a glucose
molecule?

9. Series of Oxidation/Reduction
Reactions
•Oxidation=a molecule loses electrons or H
atoms
•Reduction=a molecule gains electrons or
H atoms
LEO goes GER

10. What molecules are going to
accept the electrons or H atoms?
•Hydrogen Acceptors:
–NAD
+
–FAD
Both are coenzymes

12. Important Enzymes In Respiration
•Isomerases= converts a molecule into an
isomer

13. Important Enzymes In Respiration
•Dehydrogenases and Hydrogenase
=Transfer “H”s

14. Important Enzymes In Respiration
•Kinases and Phosphatases= Transfer
phosphate groups

15. Anaerobic Respiration Steps
1.Glycolysis (Splitting of glucose)
•Start with one molecule of glucose
•Don’t need O
2
•Process happens in cytoplasm of
eukaryotes and prokaryotes
•Need to use 2 ATPs to start reaction
•Form 2 NADH
•Form 4 ATPs (so net 2 ATPs)
•Form 2 Pyruvic Acid Molecules (3 Carbons)

16. PGAL
(Activation Energy)

18. Anaerobic Respiration Steps
2. This step only happens in prokaryotes
and eukaryotic muscle cells experiencing
muscle fatigue or oxygen debt and yeast :
FERMENTATION (Primitive)
2Pyruvic Acid 2 ethyl alcohol + 2 CO
2
+2NAD (From NADH)
2Pyruvic Acid 2 lactic Acids + 2 NAD (From NADH)
Yeast and Bacteria
Bacteria and Muscle fatigue

20. Types of Anaerobic Organisms
•Facultative Anaerobes= (Switch hitters)
–If O
2
is present, it will do aerobic respiration
–If no O
2
then it will do anaerobic respiration
–Ex. Yeast

21. Types of Anaerobic Organisms
•Obligate or Strict Anaerobes= only do
anaerobic respiration
–They can die in the presence of O
2
–Ex. Some types of bacteria

22. Anaerobic Respiration Stops Here

23. What do Aerobic Organisms do?
•Aerobic Respiration begins here!

24. Aerobic Respiration Steps
1.Glycolysis with NO FERMENTATION!!!!!
2.Pyruvic Acid Breakdown

25. Pyruvic Acid Breakdown
Pyruvic Acid
In terms of numbers, double everything for each molecule of glucose
Decarboxylation
Reaction

26. End Result of Pyruvic Acid
Breakdown
1 NADH/ Pyruvic Acid=2 NADH/Glucose
Molecule
1 CO
2/ Pyruvic Acid=2 CO
2/Glucose
Molecule

27. Aerobic Respiration Steps
3. Krebs Cycle (a.k.a Citric-Acid Cycle)
–Occurs in Matrix Region of Mitochondrion

28. Cycle goes around once for each Acetyl CoA, So 2 turns/Glucose Molecule

29. Kreb’s Cycle Bottom Line
3 NADH/Turn= 6 NADH/Glucose Molecule
1 FADH
2/Turn=2 FADH
2/Glucose Molecule
1 ATP/Turn =2 ATP/ Glucose Molecule
[1 GTP/Turn =2 GTP/Glucose Molecule]
2 CO
2/ Turn =4 CO
2/Glucose Molecule

30. So Far Not Too Many ATPs
formed!

31. But we got all those NADHs and
FADH
2
s!

32. What happens to them?
They move to the inner membrane cristae of the
mitochondria
4. Chemiosmosis and the Electron Transport Chain

33. 100 ATP
made/sec

34. Electron Transport Chain
•The electrons of H
+
s (of FADH
2 and
NADH) are transferred from one
membrane carrier to another membrane
carrier (Cytochromes)
•The electrons lose energy as they are
transferred (like hot potato)
•This energy drives membrane pumps
involved with Chemiosmosis

35. Electron Transport Chain
•Once the electrons have lost all energy
they combine with O
2 and H
+
to form H
2O

36. Chemiosmosis
•The creation of a concentration gradient of
H
+
ions across the inner membrane. This
involves active pumping of H
+
s.
•The H
+
s then diffuse down their
concentration gradient through an ATP
Synthase enzyme that produces ATP
•Process produces about 32 ATP

37. •Electron Transport Chain Animation

38. Aerobic Cellular Respiration
C
6H
12O
6 + 6O
2 6CO
2 + 6H
2O + 36 ATP
Fact:
Every day a person uses 10
25
ATPs

39. Poisons
•Cyanide and Carbon Monoxide
–Block last electron carrier
•Rotenone (Insect Poison)
–Block initial electron carrier
•Oligomycin (Antifungal cream)
–Blocks ATP Synthase function

40. What if you get low on carbs?
1.Fats (Gives 2X ATP #s compared to
glucose)
•However, need to be twice as active to
“burn” fat
•Breakdown into glycerol and fatty acids
•Glycerol converted into a glycolysis
intermediary
•Fatty acids converted into Acetyl CoA

41. What if you get low on carbs?
2. Proteins (yields same amount of ATP as
carbs)
NOT the preferred energy source
Amino acids converted into:
•Pyruvic Acid
•Acetyl CoA
•Kreb’s Cycle Intermediary