BIO103 - CH08 VOCAB - energy and metabolism

matter

Anything that takes up space and has mass.

energy

The capacity to cause change, especially to do work (to move matter against an opposing force).

kinetic energy

The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter.

heat

Thermal energy in transfer from one body of matter to another. In other words, ______ is simply the flow of thermal energy.

thermal energy

Kinetic energy due to the random motion of atoms and molecules; energy in its most random form. Heat is the transfer of this form of energy from one body of matter to another. NOTE: this form of energy is contained within a system and is responsible for its temperature.

calorie

The amount of heat energy required to raise the temperature of 1 gram (g) of water by 1o Celsius (oC); also, the amount of heat energy that 1 g of water releases when it cools by 1o C.

potential energy

The energy that matter possesses as a result of its location or spatial arrangement (structure).

chemical energy

Energy available in molecules for release in a chemical reaction; a form of potential energy.

metabolism

The totality of an organism's chemical reactions, consisting of catabolic and anabolic pathways, which manage the material and energy resources of the organism.

metabolic pathway

A series of chemical reactions that either builds a complex molecule (anabolic pathway) or breaks down a complex molecule to simpler molecules (catabolic pathway).

catabolic pathway

A metabolic pathway that releases energy by breaking down complex molecules to simpler molecules.

anabolic pathway

A metabolic pathway that consumes energy to synthesize (build) a complex molecules from simpler molecules.

thermodynamics

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

First Law of Thermodynamics

The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.

Second Law of Thermodynamics

Every energy transfer or transformation increases the entropy (= molecular disorder, randomness) of the universe. Usable forms of energy are at least partly converted to heat.

entropy

A measure of molecular disorder, or randomness.

free energy

The portion of a biological system's energy that can perform work... when temperature and pressure are uniform throughout the system.

exergonic reaction

A spontaneous chemical reaction in which there is a net release of free energy.

endergonic reaction

A nonspontaneous chemical reaction in which free energy is absorbed from the surroundings.

energy coupling

In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction.

adenosine triphosphate

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells. Abbreviated as ATP.

enzyme

A macromolecule serving as a catalyst, a chemical agent that increases the rate of reaction without being consumed by the reaction. Most are proteins; some are RNAs, called ribozymes.

activation energy

The amount of energy that reactants must absorb before a chemical reaction will start.

active site

The specific region of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs.

substrate

The reactant on which an enzyme works.

cofactor

Any nonprotein molecule or ion that is required for the proper functioning of an enzyme. They can sometimes be permanently bound to the active site or may bind loosely & reversibly, along with the substrate, during catalysis.

competitive inhibitor

A substance that reduces the activity of an enzyme by entering the active site in place of the substrate, whose structure it mimics.

noncompetitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzyme's shape so that the active site no longer effectively catalyzes the conversion of substrate to product.

allosteric regulation

The binding of a regulatory molecule to a protein at one site that affects the function of the protein at a different site.

feedback inhibition

A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.

catalyst

A general term for a chemical agent that selectively increases the rate of a reaction without being consumed by the reaction; an enzyme is an example.