Total aerobic breakdown of glucose

Answer 1

Glucose can be broken down by glycogenolysis. Glucose broken down through aerobic respiration is exergonic, meaning no energy is required to jump-start the reaction, and that the products of the reaction have less energy than the reactants.

The formula for this reaction is:

G6H1206 + 602 -> 6CO2 +6H20+ATP

Where 6O2 indicates 6 Oxygen molecules.

Three metabolic stages are required for the full breakdown of glucose and acquisition of ATP (energy). First glucose is broken down into two molecules of pyruvate by the use of ten different enzymes. This requires two energy phases: An energy investment phase where two ATP molecules are used, and an energy payoff phase where two NADH molecules are earned and four ATP molecules are also earned. Once one glucose is split into two pyruvates it can enter the Citric Acid Cycle (AKA Krebs Cycle, or the Tricarboxylic Acid Cycle) of a mitochondria by a transport protein.

The Citric Acid Cycle is where most of the energy from glucose is actually stored. (There are quite a few steps to this phase and it would do any student good to memorize these steps) Release of this energy first requires a conversion of pyruvate to Acetyl Coenzyme A. Conversion of pyruvate to Acetyl CoA is completed via removal of pyruvate's carboxyl group as CO2 respiration, oxidation of the remaining molecule to form acetate by extracting electrons and storing them as NADH, and then lastly an enzyme appropriately named coenzyme A attaches to acetate in an unstable bond. There you have Acetyl Coenzyme A. Once you've got Acteyl Coenzyme A, that's the key to unlocking the door of the Citric Acid Cycle, which is where all the magic happens. So firstly, Acetyl CoA adds part of itself to Oxaloacetate, and produces and altogether different molecule called citrate. So that was Acetyl CoA to Oxaloacetate, losing CoA because that was that unstable bond we mentioened earlier remember? K, secondly, Citrate exchanges one molecule of H2O, water, for another, making it an isomer (remember an isomer can be two molecules with exactly the same formula but different structural makeups). So citrate is now known as Isocitrate. Isocitrate then gets oxidized, meaning he loses a hydrogen molecule to NAD, making another NADH. And once he's been oxidized, Mr. Isocitrate also loses a CO2 molecule. What we've got left now is a no longer Isocitrate, it's an alpha-Ketoglutarate, which goes on to lose ANOTHER CO2 molecule, and oxidized AGAIN, making yet another NADH molecule and then that remainder of a molecule links up with another coenzyme A again to form Succinyl Coenzyme A. Well, Succinyl Coenzyme A doesn't manage to last together very long. Coenzyme A leaves succinyl when a phoshpate group bullies it's way in, and then leaves again, and attaches to GDP to make GTP, (another energy-molecule like ATP). So now after all that we're left with Succinate. What step are we on? Well this is the 5th molecular transformation since Acetyl CoA, and we've got three more to go till we're back full-cycle. So Succinate loses two hydrogens, giving them away to FAD, to make FADH2. Now Succinate has become Fumarate (Step 6). Fumarate snags a water molecule along the way to becoming Malate (Step 7). Malate gets oxidized here pretty quick to complete the cycle all the way and bring us back to Oxaloacetate, and we've gone through eight molecular transformations total. We've three NADH, one FADH2 molecules and one GTP.

From the Citric Acid Cycle we move on to the Electron Transport Chain. This mechanism works as a series of proteins numbered I through IV. These proteins contain components for catabolic enzymes to function. These proteins use enzymatic reactions to remove electrons from the electron carrier molecules mentioned above (like FAD, GDP, ADP, and NAD). As electrons are removed, they are scurried over to ATP synthase, to make ATP.

Glycolysis yields about 2 ATP. The Citric Acid Cycle yields 2 ATP, but the Electron Transport Chain yields about 32-34 ATP by oxidative phosphorylation of electron carrier molecules.

Answer 2

During aerobic respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and energy in the form of ATP. This process involves three main stages: glycolysis, the citric acid cycle, and the electron transport chain. Overall, the complete breakdown of one molecule of glucose generates a total of 36-38 molecules of ATP.