IB Sports, exercise and health science A.2.3.1 ATP Production and Substrate Metabolism Key Definitions

A high-energy molecule that stores and provides energy for cellular processes, including muscle contraction and metabolism.

Adenosine triphosphate (ATP) is the primary chemical energy currency of the cell. Hydrolysis of ATP releases the energy used for muscle contraction, ion transport, and most other energy-requiring processes.

The metabolic process that builds complex molecules from simpler ones, using energy (e.g., muscle protein synthesis).

The process of releasing energy from fatty acids inside the mitochondria. Fatty acid chains are gradually broken down into acetyl CoA molecules, each cycle shortening the chain by two carbons and yielding energy.

The metabolic process that breaks down complex molecules to release energy (e.g., breaking down glucose to produce ATP).

The controlled release of energy in the form of ATP from organic molecules inside cells. It takes place mainly in the mitochondria for aerobic respiration and in the cytosol for anaerobic glycolysis.

A series of protein complexes in the mitochondria that transfer electrons to produce ATP during aerobic metabolism.

The production of glucose from non-carbohydrate sources, such as proteins and fats.

The stored form of glucose found in the liver and muscles, which can be broken down into glucose for ATP production during exercise.

The process of converting glucose into glycogen for storage, mainly in the liver and muscles.

The process of breaking down glycogen into glucose to be released into the blood for energy use.

A process that breaks down glucose or glycogen into pyruvate without the use of oxygen, producing ATP and lactic acid as a byproduct.

A series of biochemical reactions occurring in the mitochondria that further break down pyruvate to release high-energy electrons, contributing to ATP production.

A byproduct of anaerobic glycolysis that is produced when pyruvate is converted in the absence of oxygen. Accumulation of lactate contributes to muscle fatigue.

The process of releasing triglycerides from fat stores and breaking them down into glycerol and fatty acids, which can then be used to produce energy via beta-oxidation.

The total sum of all chemical reactions occurring in the body, including energy production and storage.

Cell components that are the site of aerobic ATP production. They host the Krebs cycle and the electron transport chain and are the only place in the cell where oxygen is used. Present in all human cells except red blood cells.