Enzymes as Biological Catalysts

These flashcards cover essential vocabulary related to enzymes, their action, and the factors affecting enzyme activity.

Enzyme

A biological catalyst that speeds up reactions by lowering activation energy.

Activation energy

The minimum energy required for a chemical reaction to occur.

Induced-fit model

A model of enzyme action where the active site changes shape to fit the substrate. Causes bonds to distort in substrate which lovers activation energy as more ES complexes form.

Enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate.

Specificity of enzymes

The ability of an enzyme to catalyze a specific reaction due to the complementary shape of its active site. Depended on tertiary structure as that determines shape of active site (dependent on sequence of AA).

Competitive inhibitor

A substance that competes with the substrate for the active site of an enzyme, reducing the rate of reaction.

Non-competitive inhibitor

A substance that binds to an enzyme at a site other than the active site, altering its shape and function.

Effect of temperature on enzyme activity

Increasing temperature raises reaction rates up to an optimum, after which enzymes denature reducing activity.

Effect of pH on enzyme activity

Extreme pH levels can denature enzymes, altering their active site and reducing reaction rates.

Limiting factor

A condition that restricts the rate of an enzyme-controlled reaction, such as enzyme or substrate concentration.