Notes 1.3 Enzymes Flashcards

Vocabulary practice flashcards covering fundamental topics on enzyme characteristics, mechanisms, kinetics, and regulation based on the lecture notes.

Enzymes

Special biological proteins that act as catalysts to increase the rate of metabolic chemical reactions.

Catalyst

A substance that speeds up the rate of a chemical reaction without being changed or used up during it, making it reusable.

Activation Energy

The initial energy needed to start a chemical reaction, which enzymes lower so the reaction can proceed efficiently.

Denaturation

The unfolding process where a protein's specific shape is destroyed due to factors like extreme temperature or pH, rendering it inactive.

Active Site

A specific pocket or groove on the surface of an enzyme where a substrate molecule binds and the chemical reaction takes place.

Substrate

The specific reactant molecule that binds to the active site of an enzyme.

Metabolism

The total sum of all chemical reactions occurring within an organism or cell.

Anabolic Reactions

Metabolic processes (such as dehydration synthesis) that build up complex molecules from simpler ones and require energy input.

Catabolic Reactions

Metabolic processes (such as hydrolysis) that break down complex molecules into simpler ones and release energy.

Optimal Temperature

The specific temperature at which an enzyme achieves its maximum rate of reaction, which is approximately $37\text{ }^\bullet\text{C}$ ($98.6\text{ }^\bullet\text{F}$) for human enzymes.

Enzyme Saturation

The point in an enzyme-catalyzed reaction where all active sites are filled with substrate molecules, causing the reaction rate to remain constant.

Optimal pH

The pH level at which an enzyme operates most effectively, typically pH $6\text{--}8$ for most human enzymes, and pH $1.5\text{--}3$ for stomach pepsin.

Enzyme Inhibitors

Molecules, such as poisons and drugs, that interact with an enzyme to inhibit its normal catalytic functioning.

Competitive Inhibitor

An inhibitor molecule that directly binds to the active site of an enzyme, physically blocking the substrate from entering.

Non-Competitive Inhibitor

An inhibitor molecule that binds to an allosteric site on an enzyme, causing a conformational change in the active site that prevents substrate binding.

Feedback Inhibition

A cellular control loop where the end product of a metabolic pathway blocks an enzyme near the beginning of the pathway to regulate production and maintain homeostasis.