Cellular Respiration Overview

A set of metabolic reactions and processes that occur in the cells of organisms to convert chemical energy from nutrients into ATP and release waste products.

The three distinct pathways of cellular respiration: Photorespiration, Fermentation, and Aerobic Respiration.

The chemical process by which cells convert glucose into ATP using oxygen.

The chemical equation that summarizes aerobic respiration: C6H12O6 + 6O2 → 6CO2 + 6H2O

The first stage of aerobic respiration, where glucose is broken down into two pyruvate molecules.

A three-carbon molecule created by glycolysis.

A molecule that enters the Krebs cycle and is fully oxidized into carbon dioxide.

The second stage of aerobic respiration, where pyruvate is oxidized into carbon dioxide.

Glycolysis is the first stage of cellular respiration where glucose is broken down into two pyruvate molecules. This process occurs in the cytoplasm of cells and involves a series of enzymatic reactions.

In glycolysis, glucose (a 6-carbon molecule) is split into two molecules of glyceraldehyde 3-phosphate (3-carbon molecules), requiring 2 ATP molecules in the process.

Each glyceraldehyde 3-phosphate molecule from glycolysis is then converted into pyruvate (a 3-carbon molecule), generating 4 ATP molecules and 2 NADH molecules in the process.

The second stage of glycolysis involves the transformation of pyruvate into acetyl-CoA. This process occurs inside the mitochondria of eukaryotic cells. Pyruvate loses a carbon dioxide molecule and becomes a 2-carbon acetyl group, which is then attached to coenzyme A.

Acetyl-CoA is a key molecule that delivers the acetyl group derived from pyruvate to the next step in cellular respiration, the citric acid cycle.

The Krebs Cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondrial matrix. It involves the oxidation of acetyl-CoA, releasing energy in the form of ATP, NADH and FADH2.

The citric acid cycle starts with the attachment of the acetyl group from acetyl-CoA to oxaloacetate (a 4-carbon molecule) to form citrate (a 6-carbon molecule). The cycle then proceeds through a series of reactions releasing two molecules of carbon dioxide, producing NADH, FADH2 and ATP.

The citric acid cycle runs continuously in the presence of sufficient reactants, because the final product of the cycle is also the first reactant.

The process of converting pyruvate into ethanol and carbon dioxide using NADH as a reducing agent. Occurs in the absence of oxygen.

The breakdown of glucose in absence of oxygen, converting pyruvate to lactic acid and regenerating NAD+.

The enzyme that converts pyruvate to acetaldehyde during alcoholic fermentation.

The enzyme that converts acetaldehyde to ethanol using NADH in alcoholic fermentation.

When cells use fermentation to regenerate NAD+ for glycolysis, allowing it to continue even without oxygen.

The process of converting pyruvate to lactic acid using NADH as a reducing agent. Occurs in the absence of oxygen.

Conditions that impact the efficiency of aerobic respiration in cells

Conditions that impact the efficiency of aerobic respiration in cells

The final stage of aerobic respiration where energy from NADH and FADH2 is used to create ATP. It consists of two substages: Electron Transport Chain and Chemiosmosis.

A series of protein complexes embedded in the inner mitochondrial membrane where high-energy electrons from NADH and FADH2 are passed along, releasing energy that is used to pump protons into the intermembrane space.

The movement of protons back across the inner mitochondrial membrane through ATP synthase, driven by the electrochemical gradient created by the ETC. This flow of protons powers the production of ATP.

A protein complex in the inner mitochondrial membrane that acts as a channel for protons and uses the energy released from their movement to synthesize ATP.

The process of measuring the effectiveness of aerobic respiration in plants by examining various factors influencing plant metabolism and overall health.

The temperature at which aerobic respiration occurs most efficiently, allowing for optimal enzymatic activity.

The availability of oxygen is crucial for aerobic respiration. Oxygen deficiency can limit the efficiency of the ETC, affecting ATP synthesis.

Light intensity influences photosynthesis, which in turn affects the availability of respiratory substrates, indirectly impacting respiration rates.