Chapter 6 (Metabolism: Energy and Enzymes)
About this set
Created by:
jmweiland Plus on October 4, 2010
Subjects:
honors biology, whitlock, mader
Description:
This set deals with words from Chapter 6 (Metabolism: Energy and Enzymes)
Classes:
Log in to favorite or report as inappropriate.
Order by
68 terms
Terms | Definitions |
|---|---|
 active site | region of the surface of an enzyme where the substrate binds and where the reaction occurs |
| ADP (adenosine diphsosphate) | nucleotide with two phosphate groups that can accept another phosphate group and become ATP |
| ATP (adenosine triphosphate) | nucleotide with three phosphate groups; the breakdown of ATP into ATP + P makes energy available for energy-requiring processes in cells |
| chemical energy | energy associated with the interaction of atoms in a molecule |
| chemiosmosis | ability of certain membranes to use a hydrogen ion gradient to drive ATP formation |
| coenzyme | nonprotein organic molecule that aids the action of the enzyme to which it is loosely bound |
| cofactor | nonprotein adjunct required by an enzyme in order to function; many are metal ions, others are coenzymes |
| competitive inhibition | form of enzyme inhibition where the substrate and inhibitor are both able to bind to the enzyme's active site; each complexes with the enzyme; only when the substrate is at the active site will product form |
| coupled reactions | reactions that occur simultaneously; one is an exzergonic reaction that releases energy, and the other is an endergonic reaction that requires an input of energy in order to occur |
| denatured | loss of an enzyme's normal shape so that is no longer functions; caused by a less than optimal pH and temperature |
| electron transport chain | passage of electrons along a series of membrane-bound electron carrier molecules from a higher to lower energy level; the energy released is used for the synthesis of ATP |
| endergonic reaction | products have more free energy than reactants |
| energy | capacity of do work and bring about change; occurs in a variety of forms |
| energy of activation | energy that must be added in order for molecules to react with one another |
| entropy | measure of disorder or randomness |
| enzyme | organic catalyst, usually a protein, that speeds a reaction in cells due to its particular shape |
| enzyme inhibition | means by which cells regulate enzyme activity; may be competitive or noncompetitive inhibition |
| exergonic reaction | products have less free energy than reactants |
| feedback inhibition | mechanism for regulating metabolic pathways in which the concentration of the product is kept within a certain range until binding at an allosteric site shuts down the pathway, and no more product is produced |
| free energy | the amount of energy available to perform work |
| heat | type of kinetic energy; captured solar energy eventually dissipates as heat in the environment |
| induced fit model | change in the shape of an enzyme's active site that enhances the fit between the active site and its substrate(s) |
| kinetic energy | energy that is actually doing work |
| law of conservation | energy cannot be created or destroyed but can only be changed from one form to another |
| mechanical energy | a type of kinetic energy, such as walking or running |
| metabolic pathway | series of linked reactions, beginning with a particular reactant and terminating with an end product |
| metabolism | all of the chemical reactions that occur in a cell during growth and repair |
| NAD+ (nicotinamide adenine dinucleotide) | coenzyme of oxidation-reduction that accpets electrons and hydrogen ions to become NADH + H+ as oxidation of substrates occurs; during cellular respiration, it carrie electrons to the electron transport chain in mitochondria |
| NADP+ (nicotinamide adenine dinucleotide phosphate) | coenzyme of oxidation-reduction that accepts electrons and hydrogen ions to become NADPH + H+; during photosynthesis it participates in the reduction of carbon dioxide to glucose |
| noncompetitive inhibition | form of enzyme inhibition where the inhibitor binds to an enzyme at a location other than the active site; while at this site, the enzyme shape changes, the inhibitor is unable to bind to its substrate, and no product forms |
| oxidation | loss of one or more electrons from an atom of molecule; in biological systems, generally the loss of hydrogen atoms |
| phosphorylation | in metabolic processes, a way to activate an enzyme in which the enzyme either attaches an inorganic phosphate to a molecule or mediates the transfer of a phosphate group from one molecule to another |
| potential energy | stored energy |
| product | substance that forms as a result of a reaciton |
| reactant | substance that participates in a reaction |
| reduction | gain of electrons by an atom or molecule with a concurrent storage of energy; in biological systems, the electrons are accompanied by hydrogen ions |
| substrate | reactant in a reaction controlled by an enzyme |
| vitamin | essential requirement in the diet, needed in small amounts; often part of enzymes |
| Second law of thermodynamics | energy cannot be changed from one form to another without a loss of usable energy |
| membrane | sites where chemical reactions can occur in an orderly matter |
| Adenosine triphosphate | high energy compound used to drive metabolic reactions |
| Adenosine diphosphate | ATP is constantly being generated from |
| Adenosine + ribose = | adenosine |
| in ADP, how many phosphate groups are there? | three |
| During a coupled reaction, the bond joining a phosphate group is broken by | hydrolysis |
| in the ATP cycle, the energy from exergonic reactions can be summed up by | respiration |
| in the ATP cycle, the energy for endergonic reactions goes to do | cellular work |
| chemical work | energy needed to synthesize macromolecules |
| transport work | energy needed to pump substances across plasma membrane |
| mechanical work | energy needed to contract molecules, beat flagella, etc |
| lowering energy barriers | enzymes speed up the cell's chemical reactions by |
| degradation | enzyme complexes with a single substrate molecule; substrate is broken apart into two perfect molecules |
| synthesis | enzyme complexes with two substrate molecules; substrates are joined together and released as single product molecule |
| 1 substrate and 2 products | in a hydrolysis type of reaction there are |
| 2 substrates and 1 product | in a dehydration type of reaction there are |
| substrate concentration | enzyme activity increases with this; more collision between substrate molecules and the enzyme |
| temperature | enzyme activity increases with this; too much can destroy them |
| pH | most enzymes are optimized for a particular type of this |
| reversible enzyme inhibition | when a substance known as an inhibitor binds to an enzyme and decreases its activity |
| competitive inhibitor | takes the place of a substrate in the active site |
| noncompetitive inhibitor | alters an enzyme's function by changing its shape |
| irreversible inhibition | materials irreversibly inhibit an enzyme (known as poisons) |
| cyanides | inhibit enzymes resulting in all ATP production |
| heavy metals | irreversibly bind with many enzymes |
| nerve gas | irreversibly inhibits enzymes required by nervous system |
| certain pesticides | too toxic to insects because they inhibit key enzymes in the nervous system |
| many antibodies | inhibit enzymes that are essential to the survival of disease-causing bacteria |
| penicillin | inhibits an enzyme that bacteria use in making cell walls |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.