CH.4 How Cells Obtain Energy Flashcards
acetyl CoA
the combination if an acetyl group form pyretic and coenzyme. A which is made from pantothenic acid (a B-group vitamin)
activation energy
the amount of initial energy necessary for reactions to occur
active site
a specific region on the enzymes where the substrate binds.
allosteric inhibition
the mechanism for inhibiting enzyme action in which a regulatory molecule binds to a second site and initiates a conformation change in the activation site, preventing binding with the substrate
anabolic
the pathway that requires a net energy inout to synthesize complex molecules from simpler ones
anaerobic cellular respiration
the use of an electron acceptor other than oxygen to complete metabolism using electron transport-based chemiosmosis
ATP
(adenosine triphosphate) the cells’s energy currency
ATP synthase
a membrane-embedded protein complex that regenerates ATP from ADP with energy from protons diffusing through it
bioenergetics
the concept of energy flow through living systems
catabolic
the pathway in which complex molecules are broken down into simpler ones, yielding energy as an additional product of the reaction
chemiosmosis
the movement of hydrogen ions down their electrochemical gradient across a membrane through ATP synthase to generate ATP
citric acid cycle
a series of enzyme-catalyzed chemical reactions of central importance in all living cells that harvest the energy in carbon-carbon bonds of sugar molecules to generate ATP; the citric acid cycle is anaerobic metabolic pathway because it requires oxygen in later reactions
competitive inhibition
a general mechanism of enzyme activity regulation I. which a molecule other than enzymes substrate is able to bind the active site and Oren t the substrate itself from binding, thus inhibiting the overall rate if reaction for the enzyme.
electron transport chain
a series of four large, multi-protein complexes embedded in the inner mitochondrial membrane that accepts electrons form donor compounds and harvests energy form a series of chemical reactions to generate a hydrogen ion gradient across the membrane
endergonic
a chemical reaction that results in products that store more chemical potential energy than the reactants
enzyme
a molecule that catalyzes a biochemical reaction
exergonic
a chemical reaction that results in oviducts with less chemical potential energy than the reactants, plus the release of free energy
feedback inhibition
a mechanism of enzyme activity regulation in which the product of a reaction or the final product if a series of sequential reactions inhibits enzyme for an earlier step in the reaction series
fermentation
the steps that follow the partial oxidation of glucose vis glycolysis to regenerate NAD+; occurs in the absence of oxygen and uses an organic compounds as the final electron acceptor
glycolysis
the process of breaking glucose into two three- carbon molecules with the production of ATP and NaDH
heat energy
the energy transferred from one system to another that is not work
kinetic energy
the type of energy associated with objects in motion
metabolism
all the chemical reactions that take place inside cells, including this that use energy and those the release energy
noncompetitive inhibition
a general mechanism of enzymes activity regulation in which a regulatory molecule binds to a site other than the active site and prevents the active site form binding the substrate; thus, the inhibitor molecule does not compete with the substrate for the active site; allosteric inhibition is a form of noncompetitive inhibition
oxidative phosphorylation
the production of ATP by the transfer of electrons down the electron transport chain to create a proton gradient that is used by ATP synthase to add phosphate groups to ADP molecules
potential energy
the type of energy that refers to the potential to do work
substrate
a molecule on which the enzymes acts
thermodynamics
the science of the relationships between heat, energy, and work
