1. Glycolysis and Cellular Respiration
Harvesting Energy
Glycolysis and Cellular Respiration

2. Energy from Glucose
__________and _______________ break glucose and other carbon compounds apart.
Energy released from broken bonds is harnessed to make ____ to run cell processes.
ALL Eukaryotic organisms (including plants) carry out cellular respiration ____ _____ _____.

3. Cellular respiration takes place in the mitochondria.
mitochondrion
outer
membrane
intermembrane
space
inner
membrane
matrix
cristae

4. ATP is produced in great quantities by mitochondria.
Remember ATP?
Adenosine triphosphate, the universal energy carrier, is a single nucleotide (adenine) with two extra phosphate groups attached.
ATP is produced in great quantities by mitochondria.

5. Review: ATP is produced and used in coupled reactions
______________
(glucose breakdown)
_____________
(ATP synthesis)
______________
(ATP breakdown)
_______________
(protein synthesis)
ADP + heat
net ____________
“downhill” reaction

6. ________________ breaks the sugar down further, producing 32-34 ATPs.
Overview
____________ splits sugar into two 3-carbon chains (pyruvate), producing 2 ATPs
glucose
2 NADH
glycolysis
2 ATP
(cytosol)
2 pyruvate
2 NADH
2 acetyl CoA
________________ breaks the sugar down further, producing ATPs.
6 NADH
Krebs
(citric acid)
cycle
2 ATP
(mitochondrion)
2 FADH2
electron transport chain
32 or 34
ATPs
Total 36 or 38
ATPs
NADH and FADH (derived from vitamins B3 and B2) act as electron carriers.

7. in cytosol– no oxygen required if no O2 available in mitochondria–
glucose
in cytosol–
no oxygen required
if no O2 available
fermentation
in mitochondria–
oxygen required
cellular respiration

8. __________ is split in half. Net gain of 2 ATPs
Glycolysis
in cytosol 2
ATP 2
ADP 4
ADP 4
ATP 2 2
glucose
G3P
pyruvate
fructose
bisphosphate 2
NAD+ 2
NADH
1 Glucose activation
2 Energy harvest
__________ is split in half.
Net gain of 2 ATPs
2 ATPs are used.
End product is ________

9. Glycolysis Animation
Role of B Vitamins

10. Cellular respiration begins with moving the products of glycolysis into the mitochondrion.
1 Formation of
acetyl CoA 3
_______ 3
NAD+
FAD
_______
____
coenzyme A
coenzyme A
CoA
2 Krebs
cycle 2
______
__________
________
NAD+
_______
ADP
In cytosol
_______
In mitochondrion

11. Krebs Cycle Animation

12. Electron carriers from the Krebs cycle are used to power an electron transport chain and proton pump.
Oxygen is required
to accept energy-
depleted electrons.
Flow of H+ down
concentration gradient
powers ATP synthesis.
High-energy electron carriers
from acetyl CoA formation, Krebs
cycle, and glycolysis feed into the ETC.
NADH
FADH2
1/2O2
2e–
2H+
H2O
ADP + Pi
ATP
FAD
matrix
NAD
inner
membrane
intermembrane
space
Energy from
high-energy electrons
powers active
transport of H+ by ETC.
High H+ concentration is
generated by active transport.
H+ channel is coupled to
ATP synthesizing enzyme.

13. Electron Transport Chain Animation

14. Main points of cellular respiration
Cellular respiration takes place in the mitochondria.
The product of glycolysis is broken down completely, releasing CO2 as a waste gas.
The electron transport chain/proton pump complex uses energized electrons to produce up to 36 ATPs from each molecule of glucose.

15. Mitochondria animation on XVIVO

16. glucose
(cytosol)
In the absence of _________, cellular respiration cannot continue. Pyruvate from glycolysis is fermented, producing ____ ____ or ______.
2 NADH
glycolysis
2 ATP
Cellular respiration requires ______ to pick up electrons and protons at the end of an electron transport chain
lactate
2 pyruvate or
fermentation
(no O2)
ethanol + CO2
cellular respiration
2 NADH
2 CO2
2 acetyl CoA
Krebs
(citric
acid)
cycle
4 CO2
2 ATP
H2O
6 NADH
1/2O2
2H+
2 FADH2
2e–
32 or 34
ATPs
electron transport chain
(mitochondrion)

17. If the mitochondria can’t accept pyruvate, NADH from glycolysis accumulates, depleting NAD+. Fermentation uses excess NADH to convert pyruvate to lactic acid or ethanol.
regeneration
NAD+
NADH
NADH
NAD+
NADH 2 2
(glycolysis)
(fermentation)
glucose
pyruvate
lactate 2
ADP 2
ATP

18. Other monomers can be broken down for energy as well.
Fatty acids have more energy per gram than sugars, so are preferred as energy storage.
Other monomers can be broken down for energy as well.
(cytosol)
complex
carbohydrates
fats
proteins
glucose
amino
acids
glycerol
Glycolysis
fatty acids
pyruvate
acetyl
CoA
While brain cells usually must have glucose, other cells can use fatty acids and amino acids for energy.
Amino acids must be stripped of nitrogen first, which is disposed of in the kidneys.
Krebs
cycle
electron
carriers
Electron
transport chain
synthesis
(mitochondrion)
breakdown

19. What if you take in more monomers than you need to produce ATP?
Simple sugars are broken apart in glycolysis. If the mitochondria does not need Acetyl CoA, the acetate is released and can be used to synthesize fatty acids to make fats for storage.

20. Amino acids not needed for protein synthesis are stripped of their amine groups. The remaining carbon backbone can either be used to make Acetyl CoA, or can be used to synthesize fatty acids.

21. Recap
Cellular respiration breaks organic compounds down into inorganic compounds.
In the process, chemical energy in compounds such as sugar is converted to chemical energy in ATP.
ATP is used to run cellular processes.
ALL Eukaryotic organisms carry out cellular respiration.