Bio Ch 6 Flashcards
Energy
ability to do work or bring about a change
Kinetic energy
energy of motion
Potential energy
stored energy whose capacity to accomplish work is not being used at the moment
Chemical energy
ex. food; composed of organic molecules such as carbohydrates, proteins, and fat
Mechanical energy
chemical energy converted into a type of kinetic energy
Heat
type of kinetic energy associated with the random motion of molecules
Laws of thermodynamics
2 laws explaining energy and its relationships and exchanges; 1st (law of conservation): energy cannot be created or destroyed but can only be changed from one form to another; 2nd: energy cannot be changed from one form to another without a loss of usable energy
Entropy
relative amount of disorganization
Metabolism
sum of all the chemical reactions that occur in a cell
Reactants
substances that participate in a reaction
Products
substances that form as a result of a reaction
Free energy
amount of energy left to do work after a chemical reaction has occurred (AKA delta G)
Exergonic reactions
Reactions that are spontaneous and release energy
Endergonic reactions
Reactions that require an input of energy to occur
ATP (adenosine triphosphate)
common energy currency of cells
ADP (adenosine diphosphate)
ATP is constantly being generated from this (and a molecule of inorganic phosphate)
Mole
unit of measurement in chemistry; equal to the molecular weight of a molecule expressed in grams
Enzyme
protein molecule that functions to speed a chemical reaction without itself being affected by the reaction
Ribozymes
made of RNA instead of proteins; serve as biological catalysts; involved in the synthesis of RNA and the synthesis of proteins at ribosomes
Metabolic pathway
series of linked reactions; begin with a particular reactant and end with a final product
Energy of Activation (Ea)
energy that must be added to cause molecules to react with one another
Substrates
reactants in an enzymatic reaction
Active Site
one small part of an enzyme that associates directly with the substrate(s)
Induced Fit Model
enzyme is induced to undergo a slight alteration to achieve optimum fit for the substrates
Degradation
substrate is broken down to smaller products
Synthesis
substrates are combined to produce a larger product
Denatured
if the temperature rises above a certain point, enzyme activity eventually levels out and then declines rapidly because the enzyme is this; enzyme changes shape when this happens and can no longer bind its substrate(s) efficiently
Cofactors
many enzymes require the presence of an inorganic ion or nonprotein organic molecule at the active site in order to work properly; inorganic ions include copper, zinc, or iron
Coenzymes
nonprotein organic molecules; = cofactors that participate in the reaction, may even accept or contribute atoms to the reactions
Vitamins
relatively small organic molecules that are required in trace amounts in our diet and in the diets of other animals for synthesis of coenzymes
Enzyme inhibition
occurs when a molecule (the inhibitor) binds to an enzyme and decreases its activity
Noncompetitive inhibition
inhibitor binds to the enzyme at a location other than the active site
Allosteric site
site other than the active site that an inhibitor binds to, thus changing the function of the enzyme
Competitive inhibition
occurs when an inhibitor and the substrate compete for the active site of an enzyme
Oxidation-reduction reaction
transfer of electrons from one molecule to another
Oxidation
loss of electrons
Reduction
Gain of electrons
Redox reaction
AKA oxidation/reduction reaction
NADP+
Nicotinamide Adenine dinucleotide phosphate; a high-energy electron-carrier molecule (coenzyme) of oxidation-reduction that is required for glucose production
NAD+
Nicotinamide adenine dinucleotide; in metabolic pathways, most oxidations such as those that occur during cellular respiration involve a coenzyme called this
Electron Transport Chain (ETC)
series of membrane-bound carriers that pass electrons from one carrier to another via redox reactions
ATP synthases
protons can move back across the membrane by interacting with other enzyme complexes in the membrane called this
Chemiosmosis
production of ATP due to a hydrogen ion gradient across a membrane
