Biology: Enzymes, Energy, and Metabolic Reactions Overview

Kinetic energy

Energy of movement, e.g., light energy, electricity, heat.

Potential energy

Stored energy, e.g., in chemical bonds.

Hydrolysis of ATP

Has a ΔG of -7.3 KJ, releases energy.

Exergonic reaction

Releases energy.

Endergonic reaction

Absorbs energy.

Phosphorylation of glucose

Adding an inorganic phosphate to glucose.

Enzymes

Proteins that act as biological catalysts.

Activation energy (EA)

Energy needed to reach the transition state.

Transition state

Unstable intermediate state between reactants and products.

Catalysts

Substances that increase the rate of chemical reactions.

Chemical equilibrium

Point where concentrations of reactants and products are not changing.

Substrate specificity

Substrate must have the correct shape to bind the active site of the enzyme.

Lock and Key model

Structures are fixed and unchangeable.

Induced fit model

Binding of substrate changes the shape of the active site.

Competitive inhibitors

Compete for the active site.

Non-competitive inhibitors

Bind somewhere else other than the active site.

Allosteric enzymes

Bind activators and inhibitors at sites other than the active site.

Metabolic pathway

Series of chemical reactions where molecules are broken down or built up.

ADP

Adenosine diphosphate, 2 phosphate groups attached.

AMP

Adenosine monophosphate, single phosphate group attached.

First Law of Thermodynamics

Energy is neither created nor destroyed.

Entropy

Energy not available to do work, increases disorder.

Free energy (ΔG)

Amount of energy available to do work in a chemical reaction.

Energetic coupling

Process where a spontaneous reaction drives a non-spontaneous reaction.

Catabolism

Set of reactions that breaks down molecules into smaller units.

Anabolism

Set of reactions that builds molecules from smaller units.