Beginner Topic 1007 of 1102 Biochemistry, Environment & Industry

ATP

Adenosine triphosphate is the energy currency of cells.

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In-depth explanation of ATP

Adenosine triphosphate is the main energy carrier of the cell, made of adenine, ribose and a chain of three phosphate groups. Energy is stored in the phosphoanhydride bonds, although these bonds are not unusually strong; the energy release comes from the products being more stable and more hydrated than the reactants. Hydrolysis of ATP to ADP and inorganic phosphate releases about 30.5 kJ per mole under standard conditions, and the free energy change in cells is larger because concentrations are far from standard. The cell regenerates ATP continuously through catabolic reactions, so turnover is very rapid. Coupling exergonic ATP hydrolysis to endergonic reactions drives biosynthesis, active transport and muscle contraction.

Going deeper: ATP

Key ideas: Adenosine triphosphate, adenine plus ribose plus three phosphates. Hydrolysis to ADP plus Pi has standard delta G of about minus 30.5 kJ per mole (about minus 50 in cells) because of charge repulsion, resonance stabilization of products and better solvation. A human turns over roughly their body weight of ATP daily.

Common mistakes and connections: Students say energy is stored in the phosphate bond; the energy release comes from the overall lower energy of products, bond breaking itself costs energy. ATP is not a long-term store; fats and glycogen are. Links to coupled reactions, glycolysis, oxidative phosphorylation.

Visualization of ATP

Hydrolysis of ATP to ADP and phosphate releases about 30.5 kJ per mole under standard conditions, which is coupled to drive endergonic reactions. The interactive lesson shows this as a live animation or chart.

Worked example and use case

Myosin heads use ATP hydrolysis to power each step of muscle contraction.

Frequently asked questions about ATP

What is ATP?

Adenosine triphosphate is the energy currency of cells.

Is ATP a beginner, intermediate or advanced topic?

ATP is a beginner topic in Biochemistry, Environment & Industry. It needs no earlier chemistry lessons and is a good starting point.

What should I learn before ATP?

Study these earlier topics in Biochemistry, Environment & Industry first: PCR, CRISPR, Metabolism.

What comes after ATP?

The next topics in Biochemistry, Environment & Industry are Glycolysis and Krebs Cycle.

Can I practise ATP with quizzes?

Yes. The interactive lesson includes a self-check question on ATP, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.

Where ATP fits in Biochemistry, Environment & Industry

ATP is topic 32 of 127 in Biochemistry, Environment & Industry.

ATP