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State the Three Stages of Cellular Respiration.

Answer – The three stages of cellular respiration are glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain.

Explanation:

Cellular respiration involves the breakdown of glucose to produce ATP. There are three stages (reactions) in which this process occurs:

Glycolysis: This is the first stage of cellular respiration, and it takes place in the cytosol (cytoplasmic matrix) of the cell. During glycoly s is, glucose is converted into two pyruvates, resulting in 2 ATP and 2 NADH molecules.

The citric acid cycle (the Krebs cycle): This second stage of cellular respiration takes place in the matrix of the mitochondrion. In this, Pyruvate loses a CO2 and two H+s, becoming acetyl-CoA. This conversion also results in the formation of NADH, FADH2, and ATP, which are all energy-carrying molecules.

Electron transport chain/oxidative phosphorylation: This third and final stage takes place in the inner membrane of the mitochondrion. During this stage, the energy-carrying molecules produced during the Krebs cycle are used to generate ATP through chemiosmosis (proton movement).

A diagram depicting the three stages of cellular respiration in a cell — The three stages of cellular respiration are glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain.
Image credit: RegisFrey / Wikimedia Commons (licensed under CC BY-SA 3.0)

Popular Questions

An enzyme is needed for the Krebs Cycle. It will be made following the directions contained in a gene of one of the ___ found in the ___ of the cell. A portion of the double strand of ___ splits apart between the weak ___ bonds holding the bases together. This portion contains the code for building the enzyme. The code message begins with a triplet called ___, followed by the code, then signals the end with a triplet called the ___.

When you exercise, your muscles are using ATP to do the movements. Thus, the cell is doing cellular respiration in order to replace the ATP it has used. (A) Draw a series of diagrams showing the energy transfers that occur during exercise (include: ATP, muscle, heat, cell respiration, glucose). (B) When we exercise, we produce a lot of heat; to cool us down, our body produces sweat. According to the laws of thermodynamics, where is the heat coming from? (C) When we exercise to lose weight, where is that mass going (do we sweat it out, it turns into heat, becomes digestive waste, how do we eliminate it?)

The key event in photosystem I is the liberation of a ___ into the electron transport chain.

Your body needs a constant supply of oxygen for cellular respiration to produce the ATP needed to fuel your body processes. When you exert yourself in a strenuous workout, the oxygen demands of your muscle cells quickly outpace the oxygen your body can provide. Skeletal muscle cells that have an insufficient oxygen supply to allow aerobic respiration to continue will undergo lactic acid fermentation. Refer to the model above. Predict what changes will occur when your body shifts from aerobic respiration to anaerobic respiration (lactic acid fermentation). Select ALL that apply. (A) Cells produce less ATP; (B) Cells use more glucose; (C) Cells produce more ATP; (D) Cells produce more carbon dioxide; (E) Lactic acid is produced as a byproduct.

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Biology Cell Biology Cellular Metabolism Cellular Respiration

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