Shared Flashcard Set

Details

Section 4: Energy
2.5 3.3 6.1
33
Biology
Undergraduate 1
10/12/2012

Additional Biology Flashcards

 


 

Cards

Term
Coenzyme
Definition
a nonprotein organic carbon-containing molecule that plays a role in catalysis by an enzyme; adds or removes chemical group from substrate; binds to active site, changes chemically, then separates
Term
Cofactor
Definition
an inorganic ion that is weakly bound to an enzyme required for its activity
Term
Activation Energy
Definition
the energy barrier that blocks the tendency for a chemical rxn to occur
Term
Substrate
Definition
the molecule(S) on which an enzyme exerts catalytic action; reactant of an enzyme catalyzed rxn
Term
Active Site
Definition
the region on the surface of an enzyme or ribozyme where the substrate binds, and where catalysis occurs; causes specificity of an enzyme
Term
Noncompetitive Inhibitor
Definition
a nonsubstrate that inhibits the activity of an enzyme by binding to a site other than its active site
Term
Coupled Reactions
Definition
chemical reaction with a common intermediate in which energy is transferred from one sideĀ of the reaction to the other
*ADP traps chemical energy to make ATP
*NAD+ traps energy released in redox rxn to make NADH
Term
Endergonic
Definition
a chemical rxn in which the products have higher free energy than the reactants, therby requiring free energy input to occur
Term
Free Energy
Definition
energy that is available for useful work, after allowance is made for the increase or decrease of disorder
Term
Enthalpy
Definition
the total energy of a system
Term
Reversible Inhibitor
Definition
inhibitors that can separate from the enzyme, allowing the enzyme to functino fully as before
Term
Entropy
Definition
a measure of the degree of disorder in any system; spontaneous rxns in a closed system are always accompanied by an increase in entropy; random thermal motion
Term
Spontaneous Reaction
Definition
reaction taht takes place on its own without an external force and another rxn is needed to drive it
Term
exergonic
Definition
*chemical rxn in which the products of the rxn have lower free energy than the reactants, resulting in a release of free energy in the form of heat, light, etc.
Term
Kinetics
Definition
movement fo particles in chemical rxns
*the rate the reaction occurs
Term
Thermodynamics
Definition
energy difference from point A to point B
Term

Feedback Inhibition

(end-product inhibition)

Definition
a mechanism for regulation a metabolic pathway in which the end product of the pathway can bind to and inhibit the enzyme that catalyzes the first committed step in the pathway
*The build up of the final product decreases production of that final product
Term
Enzyme
Definition
a catalyst protein that speeds up a biochemical rxn; lowers activation energy of a rxn
Term
Prosthetic Group
Definition
any nonprotein portion of an enzyme; distinctive, non-amino acid atoms or molecular groupings permanently bound to their enzymes
Term
Catalyst
Definition

a chemical substance that accelerates a rxn without inself being consumed in the overall course of the rxn; lowers the activation energy of a rxn

; does not cause a reaction to occur that wouldn't proceed w/o it *most nonbiological are nonspecific *most biological ARE specific

Ex: Enzymes

Term
Kinetic Energy
Definition
the energy associated with movement; energy that does work and makes changes
Term
Competitive Inhibitor
Definition
a nonsubstrate that binds to the active site of an enzyme and therby inhibits binding of its substrate
Term
Potential Energy
Definition
energy not doing work, such as the energy stored in chemical bonds, as a concentration gradient, or an electric charge imbalance; energy of state or position
Term
Metabolism
Definition
sum total of the chemical rxns occurring in a biological system at a given time
Term
Reactant
Definition
what goes in to a reaction
Term
Product
Definition
What comes out of a reaction
(always equal to reactants)
Term
Anabolic Reactions
(Anabolism)
Definition
link simple molecules to form more complex molecules; requires an input of energy (endergonic or exergonic)
Ex: glycosidic bond btwn. 2 monosaccharides
Term
Catabolic Reactions
(Catabolism)
Definition
break down complex molecules into simpler molecules and releases energy stored in chemical bonds (endergonic or exergonic)
Ex: sucrose being hydrolysed releases energy
Term
First Law of Thermodynamics
Definition
Energy is neither created nor destroyed
Term
Second Law of Thermodynamics
Definition
Disorder tends to increase~some energy becomes unavailable for doing work
Term
-delta G
Definition
spontaneous
Term
+delta G
Definition
nonspontaneous
Term
delta G=
Definition
products-reactants
Supporting users have an ad free experience!