Question

Aerobic respiration has 3 stages: glycolysis, Kreb's cycle, electron transport

chain. What happens in each stage? How many ATP molecules made during
each stage?

Answer 1

Stage 1: Splitting Glucose stage
The word glycolysis initially means “glucose splitting,” which is exactly what happens in this stage. Enzymes split a molecule of glucose into two molecules of pyruvate (also known as pyruvic acid).

Stage 2 The Krebs Cycle

Recall that glycolysis produces two molecules of pyruvate (pyruvic acid). These molecules enter the matrix of a mitochondrion, where they start the Krebs cycle. This cycle is at the center of cellular metabolism, playing a starring role in both the process of energy production and biosynthesis. It finishes the sugar-breaking job started in glycolysis and fuels the production of ATP in the process. It is also a central hub in biosynthetic reactions, providing intermediates that are used to build amino acids and other molecules. The citric acid cycle enzymes are found in all cells that use oxygen, and even in some cells that don't. The examples included here are taken from several different organisms.

Electron Transport Chain Stage.

The electron transport chain is a cluster of proteins that transfer electrons through a membrane within mitochondria to form a gradient of protons that drives the creation of adenosine triphosphate (ATP). ATP is used by the cell as the energy for metabolic processes for cellular functions.

Answer 2

What happens in each stage?

GLYCOLYSIS: "In glycolysis, glucose—a six-carbon sugar—undergoes a series of chemical transformations. In the end, it gets converted into two molecules of pyruvate, a three-carbon organic molecule. In these reactions, ATP is made, and NAD+ is converted to NADH." (Khan Academy)

KREB'S CYCLE: "This is a central driver of cellular respiration. It takes acetyl CoA—produced by the oxidation of pyruvate and originally derived from glucose—as its starting material and, in a series of redox reactions, harvests much of its bond energy in the form of NADH, FADH2, and ATP molecules. The reduced electron carriers—NADH and FADH2—generated in the TCA cycle will pass their electrons into the electron transport chain and, through oxidative phosphorylation, will generate most of the ATP produced in cellular respiration." (Khan Academy)

ELECTRON TRANSPORT: "In the electron transport chain, electrons are passed from one molecule to another, and energy released in these electron transfers is used to form an electrochemical gradient." (Khan Academy)

How many ATP molecules made during each stage?

GLYCOLYSIS: 2 ATP

KREB'S CYCLE: 2 ATP

ELECTRON TRANSPORT: 34 ATP

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Hope this helps! Please correct me if im wrong!