Cellular Respiration

Overview of Cellular Respiration

Cellular respiration is a fundamental metabolic process in which cells convert biochemical energy from nutrients into adenosine triphosphate (ATP), and release waste products. It is essential for the production of energy in all aerobic organisms.

• Definition: The process by which cells extract energy from glucose and other organic molecules.

• Main Steps: Glycolysis, Pyruvate Oxidation, Citric Acid Cycle (Krebs Cycle), and Electron Transport Chain.

• Location: Glycolysis occurs in the cytoplasm; subsequent steps occur in the mitochondria.

Glycolysis

Glycolysis is the first step of cellular respiration, breaking down glucose into pyruvate and generating small amounts of ATP and NADH.

• Reactant: Glucose (C6H12O6)

• Products: 2 Pyruvate, 2 ATP, 2 NADH

• Location: Cytoplasm

• Equation:

Pyruvate Oxidation (Link Reaction)

Pyruvate produced in glycolysis is transported into the mitochondria, where it is converted into Acetyl-CoA, releasing CO2 and producing NADH.

• Reactant: 2 Pyruvate

• Products: 2 Acetyl-CoA, 2 NADH, 2 CO2

• Location: Mitochondrial matrix

• Equation:

Krebs Cycle (Citric Acid Cycle)

The Krebs cycle is a series of reactions that further oxidize Acetyl-CoA, producing ATP, NADH, FADH2, and CO2.

• Reactant: 2 Acetyl-CoA

• Products: 2 ATP, 6 NADH, 2 FADH2, 4 CO2

• Location: Mitochondrial matrix

• Equation:

Electron Transport Chain (ETC) and Oxidative Phosphorylation

The ETC uses electrons from NADH and FADH2 to generate a proton gradient, which drives ATP synthesis. Oxygen is the final electron acceptor, forming water.

• Reactants: NADH, FADH2, O2

• Products: ATP, H2O

• Location: Inner mitochondrial membrane

• Equation:

Summary Table: Key Steps and Products of Cellular Respiration

Overall Equation for Cellular Respiration

The overall process of cellular respiration can be summarized by the following equation:

Additional info:

All organisms produce these results, but the number of ATP molecules generated can vary depending on the efficiency of the process and the organism.