Adenosine Triphosphate (ATP)

ATP (Adenosine Triphosphate) (Definition)

what is it made of

nature of ATP

ATP is a nucleotide consisting of the nitrogenous base adenine, the carbohydrate ribose, and three phosphate groups, or a triphosphate.

The covalent bonds between phosphate groups are high energy bonds.

adenosine diphosphate consists of an adenine and a ribose, but contains only two phosphates.

Adenosine monophosphate is the same molecule but with only one phosphate group.

Functions of ATP

ATP has several functions in biological systems.

ATP can be used as a precursor to synthesize nucleic acids.

ATP is a source of phosphate used by kinases to phosphorylate other molecules.

ATP is a source of energy that drives unfavorable chemical reactions.

Formation of ATP

The formation of ATP involves the addition of a phosphate group to ADP from a phosphate donor, forming ATP.

The phosphate donor can be an inorganic phosphate molecule shown on the left. The phosphate donor can also be specific molecules with a high energy phosphate bond, such as the molecule shown on the right.

ATP Breakdown to ADP

ATP breakdown to ADP can occur in two ways.

First, ATP can be broken down into ADP by the transfer of one phosphate group to another molecule, as shown here.

Or ATP breakdown to ADP can occur due to hydrolysis reaction, which yields ADP an inorganic phosphate.

Summary of ATP

In summary, ATP consists of adenine, ribose, and three phosphate groups.

ATP is a precursor of nucleic acids, a phosphate donor for kinases, and a source of energy.

ATP is formed by the addition or transfer of a phosphate group to ADP.

ATP can be broken down to ADP by transfer or hydrolysis of one phosphate group

ATP Structure

ATP Functions

1. Building block of nucleic acids

2. Phosphate donor for kinases

3. Source of energy to drive unfavorable chemical reactions

ATP Formation

ATP Breakdown

ATP Summary

• ATP consists of adenine, ribose, and three phosphate groups.

• ATP is a precursor of nucleic acids, a phosphate donor for kinases, and a source of energy.

• ATP is formed by the addition or transfer of a phosphate group to ADP.

• ATP can be broken down to ADP by transfer or hydrolysis of one phosphate group.

AMP structure

ADP Structure