• Its a catabolic process
• exergonic reaction

• Fermentation
• Aerobic Respiration
• Anaerobic respiration 

an anaerobic process that partially degrades sugars

- doesnt harvest all energy possible from the sugars

1. Glycolysis
2. Kreb Cycle or Citric Acid Cycle
3. Electron transport chain ( also called cellular respiration )

In Aerobic Respiration glucose loses electrons and the electrons go onto oxygen SO glucose is..... and oxygen is.....

• glycolysis
• Pyruvate Oxidation and Krebs Cycle
• Electron transport chain (oxidative phosphorylation)

• substrate level
• oxidative

couples redox to ATP formation

-vast majority of ATP gained from glucose comes from this

- happens during the electron transport chain

-powered by exergonic reaction (negative delta G)

takes place in the cytoplasm and does substrate level phosphorylation

- an anaerobic process because it does not involve oxygen

• happens in the mitochondrial matrix and performs substrate level phosphorylation

1. Energy Investment 
2. Energy Harvesting

1. EI-phosphate group and energy from 2 ATPs are added onto glucose to make Fructose, biphosphate (F 1, 6 BP)
2.  Fructose Biphosphate is converted to 2 G3P molecules. G3P molecules are made of 3 Carbons
3. EH- 2 G3P are converted into 2 pyruvate which release 4 ATP and 2 NADH

adding 2 phosphate groups onto glucose. adding the two groups destabilizes the ring so that it can open.

- The first phosphate group rearranges the ring a bit and the second phosphate group is put on to create F1, 6 BP

1. For 1 pyruvate molecule, 1 ATP, 3 NADH, 1 FADH2, and 2 CO2s are generated
2. So for every glucose molecule, the Krebs produces 2 ATP, 6 NADH, 2 FADH2, and 4 CO2

1. Acetyl CoA (2C)(from glycolysis) combines with Oxaloacetate (4C) to make citrate (6C)
2. functional groups are rearranged and as they are doing so, products are released
3. formation of alpha-ketoglutarate and succinyl CoA makes CO2 and NADH- so 2 of each
4. ATP is released indirectly
5. FADH2 is released
6. and as malate is converted to oxaloacetate more NADH is released

• 10 NADH and 2 FADH2
• each of the carriers each release 2 electrons into ETC
• after electrons are dumped, the carriers go back to the other reaction to pick up mor electrons

For 1 molecule of FADH2 the flow of electrons goes:

Complex 2 à Q à Complex 3 à Cytochrome C à Complex 4 à Oxygen

• each protein complex is more electronegativity than the one before and oxygen is the most electronegative of all

• becasue ATP is made using redox properties

• about 34-36 due to the ATP synthase being dependent on local microenvironment like pH, slat concentration, temperature

1 glucose à 2 NADH + 2 ATP + 2 pyruvate

2 Acetyl CoA à  4 CO2 + 6 NADH + 2 FADH2 + 2 ATP

formula for 

Electron Transport and Oxidative Phosphorylation

10 NADH + 2 FADH2 + 6 O₂ à 6 H2O + 34 – 36 ATP + 10 NAD⁺ + 2 FADH⁺

-only get two ATP from glycolysis- 0 from fermentation 

-Fermentation just regenerate NAD+ so that glycolysis can be performed again

Lactic Acid Fermentation

Alcoholic fermentation

• converts pyruvate to lactate or lactic acid
• regenerate NAD+ so glycolysis can be performed again
• in action in exhausted muscle cells
• the build up of lactic acid burns muscle fibers and damages muscles so that they have to rebuild
• also performed by some microbes and is used to produce things like yogurt and sour cream

• converts pyruvate to ethanol and CO2
• restore NAD+
• yeast is used commercially for alcohol fermentation- the CO2 makes bread rise
• Beer and wine have ethanol from fermentation

• follows exactly like Aerobic respiration, but uses other things as the electron acceptor rather than oxygen
• generates a decent amount of ATP

• follows exactly like Aerobic respiration, but uses other things as the electron acceptor rather than oxygen
• generates a decent amount of ATP