AP Biology- Unit 3: Enzymes

First Law of Thermodynamics

Energy cannot be created or destroyed, only transferred.

Second Law of Thermodynamics

Energy transfer leads to increased disorder, or entropy.

Exergonic Reactions

Reactions where the products have less energy than the reactants.

Endergonic Reactions

Reactions where the products have more energy than the reactants.

Enzymes

Biological catalysts that speed up reactions by lowering activation energy.

Activation Energy

The minimum amount of energy required to start a chemical reaction.

Enzyme Specificity

Each enzyme catalyzes only one specific kind of reaction.

Substrates

Molecules that enzymes target during enzymatic reactions.

Active Site

The special region on an enzyme where substrate binding occurs.

Induced-fit Model

The concept that enzymes change shape slightly to better fit their substrates.

Cofactors

Factors that assist enzymes in catalyzing reactions, can be organic or inorganic.

Enzyme Denaturation

The alteration of an enzyme's structure, often due to extreme temperature or pH.

Saturation Point

The concentration of substrate at which all enzyme active sites are occupied.

Competitive Inhibition

When an inhibitor competes with the substrate for the active site.

Noncompetitive Inhibition

When an inhibitor binds to an allosteric site, distorting the enzyme shape.