Chapter 6 Flashcards
(32 cards)
Definition of energy:
The ability to promote change or do work.
Definition of kinetic energy:
Energy associated with movement.
Definition of potential energy:
The energy that a substance possesses due to its structure or location.
Definition of chemical potential energy:
The potential energy contained within atoms and the bonds between atoms.
What is an exergonic reaction?
Refers to chemical reactions that release free energy and occur spontaneously.
What is an endergonic reaction?
Refers to chemical reactions that require an addition of free energy and do not proceed spontaneously.
What is adenosine triphosphate (ATP)?
A molecule that is a common energy source for all cells.
What is chemical equilibrium?
A state of a chemical reaction in which the rate of formation of products equals the rate of formation of reactants.
What is phosphorylation?
The attachment of a phosphate to a molecule.
How does a usually endergonic reaction, such as phosphorylation, occur naturally and spontaneously in our bodies?
An endergonic reaction is often coupled with an exergonic reaction for a net negative free-energy change.
What is a catalyst?
An agent that speeds up the rate of a chemical reaction without being permanently changed or consumed during the reaction.
What is an enzyme?
A protein that acts as a catalyst to speed up a chemical reaction in a cell. Lowers the activation energy.
What is an enzyme-substrate complex?
The structure produced by binding an enzyme and its substrate(s).
What is an induced fit?
The phenomenon that occurs when a substrate(s) binds to an enzyme and the enzyme undergoes a conformational change that causes the substrate(s) to bind more tightly to the enzyme.
What does affinity mean in relation to enzymes?
The degree of attraction between an enzyme and its substrate(s).
What is a competitive inhibitor?
A molecule that binds noncovalently to the active site of an enzyme and inhibits the ability of the substrate to bind.
What is a noncompetitive inhibitor?
A molecule that binds noncovalently to an enzyme at a location that is outside the active site and inhibits the enzyme’s function.
what is an allosteric site?
A site on an enzyme where a molecule can bind noncovalently and affect the enzyme’s function.
What is a ribozyme?
A biological catalyst that is an RNA molecule.
What is a metabolic pathway?
In living cells, a coordinated series of chemical reactions in which each step is catalyzed by a specific enzyme.
What is a catabolic reaction?
A metabolic pathway in which a molecule is broken down into smaller components, usually releasing energy.
What is an anabolic reaction?
A metabolic pathway that involves the synthesis of larger molecules from smaller precursor molecules. Such reactions usually require an input of energy.
What is an energy intermediate?
A molecule such as ATP or NADH that stores energy and is used to drive endergonic reactions in cells.
What is chemiosmosis?
A process for making ATP in which energy stored in an ion electrochemical gradient is used to make ATP from ADP and Pi.
