During aerobic cellular respiration, glucose reacts with oxygen, forming ATP that can be used by the cell. Carbon dioxide and water are created as byproducts….Aerobic vs anaerobic respiration.

mitochondria

Mitochondria

A major advantage of aerobic respiration is the amount of energy it releases. Without oxygen, organisms can split glucose into just two molecules of pyruvate. This releases only enough energy to make two ATP molecules. With oxygen, organisms can break down glucose all the way to carbon dioxide.

Aerobic zone: Working at 70% to 80% of your max heart rate puts you in the aerobic zone. About 45% of the calories you burn are fat. But you’re burning a higher number of overall calories compared to the other heart rate zones. You generally sustain this zone the shortest amount of time.

Aerobic respiration is done when you can supply your muscles and other organs with enough oxygen to completely oxidize glucose. Aerobic respiration is sustainable. For example (assuming that you’re in reasonable shape), if you’re walking at an aerobic pace you’ll never need to stop to catch your breath.

electron transport chain

glucose molecule

Aerobic respiration produces more ATP than anaerobic respiration due to the complete oxidation of glucose to CO2 and water. O2 acts as the terminal electron acceptor in the electron transport chain and gets reduced to water. Most of the ATPs are produced by oxidative phosphorylation in the electron transport chain.

The ATP generated in this process is made by substrate-level phosphorylation, which does not require oxygen. Fermentation is less efficient at using the energy from glucose: only 2 ATP are produced per glucose, compared to the 38 ATP per glucose nominally produced by aerobic respiration.

Aerobic respiration involves four stages:

• glycolysis,
• a transition reaction that forms acetyl coenzyme A,
• the citric acid (Krebs) cycle, and an electron transport chain and.
• chemiosmosis.

glycolysis

Glycolysis. The first step of aerobic respiration is glycolysis. This step takes place within the cytosol of the cell, and is actually anaerobic, meaning it does not need oxygen.

Krebs cycle (or Citric acid cycle) This breaks down the pyruvic acid to carbon dioxide. This produces 2 ATP and 6 NADH , for every glucose molecule entering glycolysis. The Krebs cycle takes place inside the mitochondria. The Krebs cycle produces the CO2 that you breath out.

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