Enzymes and Metabolic Reactions

Vocabulary flashcards covering key terms and concepts related to enzymes and metabolic reactions.

Enzyme

A macromolecule that acts as a catalyst to speed up a chemical reaction without being consumed.

Activation Energy

The energy required to push reactant molecules to the top of an energy barrier for a reaction to occur.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing permanent chemical change.

Substrate

The reactant on which an enzyme acts.

Active Site

The specific region of an enzyme where substrate binding occurs.

Induced Fit

The change in shape of an enzyme's active site to snugly accommodate the substrate after initial contact.

Competitive Inhibitor

A substance that competes with the substrate for binding to the active site of an enzyme.

Noncompetitive Inhibitor

A substance that reduces the activity of an enzyme but does not compete with the substrate for the active site.

Cofactor

Nonprotein helpers that assist enzymes in catalytic activity.

Coenzyme

An organic cofactor that assists enzyme activity and may be derived from vitamins.

Endergonic Reaction

A reaction that requires energy input and has a positive change in free energy.

Exergonic Reaction

A reaction that releases energy and has a negative change in free energy.

Thermal Energy

Energy in the form of heat that can help to achieve the activation energy needed for reactions.

Transition State

The unstable condition when reactants have absorbed enough energy for bonds to break.

Metabolism

The totality of an organism's chemical reactions, consisting of catabolic and anabolic pathways.

Protein Denaturation

The alteration of a protein's native conformation, which can disrupt enzyme activity.

Optimal Temperature

The temperature at which an enzyme exhibits the highest activity.

Enzyme Saturation

A state where all active sites of enzyme molecules are engaged by substrates.

Thermodynamics

The study of energy transformations that occur in a collection of matter.

Chemical Reaction

The process in which one or more substances are converted into different substances.

Hydrolysis

The chemical process of breaking down a compound by reaction with water.

Molecular Recognition

The process by which a molecule interacts selectively with a specific target.

Catalytic Cycle

The sequence of events in which an enzyme converts substrate into product.

Concentration Gradient

A difference in the concentration of a substance across a distance.

Allosteric Regulation

The regulation of an enzyme by binding an effector molecule at a site other than the active site.

Biological Catalyst

An enzyme that accelerates a biochemical reaction in living organisms.

Specificity

The ability of an enzyme to choose exact substrates from a group of similar chemical molecules.

Metabolic Pathways

Series of chemical reactions in cells where the product of one reaction is the substrate for the next reaction.

Chemical Bonds

The connections between atoms in a molecule, which can be broken and formed during chemical reactions.

Hydrogen Bond

A weak bond formed between a hydrogen atom and an electronegative atom.

Ionic Bond

A chemical bond formed through the attraction between oppositely charged ions.

Free Energy

The amount of energy available to do work during a chemical reaction at constant temperature and pressure.

Thermal Agitation

The random movement of molecules due to thermal energy increase.

Reaction Rate

The speed at which reactants are converted to products in a chemical reaction.

Chemical Energy

The potential energy stored in chemical bonds.

Biochemical Reaction

Any chemical reaction that occurs within a living organism.

Sarin

A potent nerve agent that irreversibly inhibits acetylcholinesterase, an essential enzyme in the nervous system.

Antibiotic

A substance that kills or inhibits the growth of bacteria by targeting specific enzymes.

Evolution of Enzymes

The process by which enzymes change and adapt over time through mutations and natural selection.

Metabolic Poison

Chemicals that disrupt metabolic processes, often by inhibiting enzyme function.

Reaction Mechanism

The step-by-step sequence of elementary reactions by which overall chemical change occurs.