(8) Metabolism and Energy-Canvas

Metabolism

The totality of all chemical reactions that take place in an organism.

Catabolic pathways

Pathways that release energy by breaking down complex molecules to simpler building blocks.

Anabolic pathways

Pathways that consume energy to build complex molecules from simpler ones.

Kinetic energy

Energy associated with the movement of objects.

Potential energy

Energy that an object has because of its location or structure.

First Law of Thermodynamics

Energy can neither be created nor destroyed; it can only change forms.

Second Law of Thermodynamics

When one form of energy is converted to another, some useful energy will be lost as useless energy like heat.

Spontaneous reaction

A reaction that can occur without the input of outside energy.

Exergonic reaction

A reaction that involves a net release of energy.

Endergonic reaction

A reaction that requires the input of outside energy and does not involve a release of energy.

ATP

A molecule that powers cellular reactions by coupling spontaneous reactions with non-spontaneous reactions.

Enzymes

Macromolecules that catalyze chemical reactions by lowering the activation energy of that reaction.

Activation energy

The energy associated with the unstable transition state of the molecules involved in a reaction.

Competitive inhibition

A form of enzyme inhibition where the substrate cannot bind when a regulatory molecule binds to the enzyme's active site.

Allosteric inhibition

A form of enzyme inhibition where the active site becomes unavailable to substrates when a regulatory molecule binds to a different site on the enzyme.

Redox reactions

Metabolic reactions that involve the loss and gain of electrons.