Aerobic respiration | - Requires O2 + produced CO2, H20 and much ATP |
Anaerobic respiration | - Takes place in the absence of O2 + produces lactase (in animals) - Ethanol + CO2 (in plants + fungi)
- Only a little ATP in both cases |
4 stages of aerobic respiration | - Glycolysis
- Link reaction
- Krebs cycle
- Oxidative phosphorylation |
Glycolysis | - The splitting of the 6 C glucose molecule into 2 3-C pyruvate molecules
- Initial stage of both aerobic + anaerobic respiration
- Occurs in cytoplasm
- Can take place without oxygen |
Link reaction | - 3-carbon pyruvate molecules enter into a series of reactions which lead to the formation of acetylcoenzyme A (2 C molecule)
- Matrix of mitochondria |
Krebs cycle | - Introduction of acetylcoenzyme A into a cycle of oxidation-reduction reactions
- Yield some ATP, large quantity of reduced NAD and FAD
- Matrix of mitochondria |
Oxidative phosphorylation | - Electrons derived from reduced NAD + FAD bind w/ O2
- The energy released from these oxid-red reactions is used for synthesis of ATP from ADP + pi
- Inner membrane of mitochondria |
4 stages of glycolysis | - Phosphorylation of glucose to glucose phosphate
- Splitting of the phosphorylated glucose
- Oxidation of triose phosphate
- The production of ATP |
Phosphorylation of glucose to glucose phosphate | - Before it can be split into 2
- Glucose first made more reactive by the addition of 2 phosphate molecules (phosphorylation)
- The Pi mols come from hydrolysis of 2 ATP molecules to ADP
- Lowers activation energy for the enzyme-controlled reactions that follow |
Splitting of the phosphorylated glucose | - Phosphorylated glucose split into 2 3-carbon molecules, TP |
Oxidation of triose phosphate | - H2 is removed from each of the 2 TP mols
- Transferred to NAD to form reduced NAD |
The production of ATP | - TP converted into 3 C pyruvate
- 2 mols of ATP are regenerated from ADP |
Energy yields from glycolysis | Yield from 1 glucose molecule undergoing glycolysis:
- 2 ATP (4 ATP produced, but 2 were used up in phosphorylation of glucose + so net increase is 2 molecules)
- 2 reduced NAD (these have the potential to provide energy to produce more ATP)
- 2 pyruvate |