Shared Flashcard Set

Details

Enzymes & Energy
Matt Hobbs
57
Physiology
Undergraduate 3
09/12/2011

Additional Physiology Flashcards

 


 

Cards

Term
What are proteins that function as biological catalysts?
Definition
Enzymes
Term
What are RNA molecules that function as biological catalyst?
Definition
Ribozymes
Term
List the three characteristics of a catalyst
Definition
Increases the rate of a reaction
Is not itself changed at the end of the reaction
Does not change the nature of the reaction or its final result
Term
What is the amount of energy required for a reaction to occur?
Definition
Activation energy
Term
What effect do enzymes have on the activation energy of a reaction?
Definition
They lower it
Term
Why are enzymes essential to life?
Definition
They make reactions occur at a rate that is fast enough to sustain life
Term
What part of an enzyme takes part in catalyzing a reaction?
Definition
The active site
Term
What are the reactant molecules on which an enzyme works?
Definition
Substrate
Term
What model of action describes how an enzyme and its substrate interact?
Definition
The lock-and-key model
Term
What model describes how an enzyme changes its configuration to fit together with its substrate?
Definition
The induced-fit model
Term
The temporary union of an enzyme and its substrate is referred to as what?
Definition
Enzyme-substrate complex
Term
What molecules are the result of the enzyme-substrate complex?
Definition
The products
Term
With the except of enzymes named before the establishment of international nomenclature, what suffix ends the names of all enzymes?
Definition
-ase
Term
How are classes of enzymes named?
Definition
according to their activity or job category
Term
What are enzymes that promote hydrolysis?
Definition
Hydrolases
Term
What are enzymes that catalyze the removal of phosphate groups?
Definition
Phosphatases
Term
What are enzymes that catalyze dehydration synthesis?
Definition
Synthases and Synthetases
Term
What are enzymes that remove hydrogen atoms from their substrates?
Definition
Dehydrogenases
Term
What are enzymes that add a phosphate group to particular molecules?
Definition
Kinases
Term
What are enzymes which rearrange atoms within their substrate molecules to form structural isomers such as glucose and fructose?
Definition
Isomerases
Term
Different organs may have different models of the same enzyme that differ in one or a few amino acids. What are these different models called?
Definition
Isoenzymes
Term
Within the temperature range from 0 degrees Celsius to 37 degrees Celsius, what happens to the activity of an enzyme as the temperature rises?
Definition
Activity increases
Term
What happens to the activity of an enzyme within the human body as the temperature rises above 37 degrees Celsius?
Definition
It decreases
Term
What is the narrow range of pH within which an enzyme exhibits its peak activity?
Definition
The pH optimum
Term
What happens to the activity of an enzyme if the pH is not with the pH optimum for that enzyme?
Definition
It decreases
Term
Why does the activity of an enzyme decrease if the pH is not within its optimum range?
Definition
the configuration of the enzyme changes
Term
What are inorganic substances which are necessary for an enzyme to function properly?
Definition
Cofactors
Term
What are organic molecules that are necessary for enzymes to function properly?
Definition
Coenzymes
Term
What are precursor forms of enzymes?
Definition
zymogens
Term
What is the process in which a phosphate group is added to a molecule?
Definition
Phosphorylation
Term
At any given level of enzyme concentration, the rate of product formation will increase as the substrate concentration increases. When the relationship between the substrate concentration and the reaction rate reaches a plateau, what has happened to the enzyme?
Definition
It has been saturated
Term
Some enzyme reactions are reversible. What principle states that the reaction will be driven from the side of the reaction where the concentration is the highest?
Definition
Law of mass action
Term
What is a squence of enzymatic reactions that begins with an initial substrate, progresses through a number of intermediates, and ends with a final product?
Definition
Metabolic pathway
Term
What is the process in which a phosphate group is removed form a molecule?
Definition
Dephosphorylation
Term
What is a form of negative feedbaack which prevents the over accumulation of the end product of a pathway?
Definition
End-product inhibition
Term
What mechainism occurs when the end product of a metabolic pathway combines with a part of an enzyme other than the active site to inhibit the pathway?
Definition
allosteric inhibition
Term
What is an inherited defect in one of the genes for an enzyme that is part of a metabolic pathway?
Definition
an inborn error of metabolism
Term
What is the flow of energy through living systems?
Definition
Bioenergetics
Term
What priciple states that energy can be neither created nor destroyed, but it can be transformed from one form to another?
Definition
The 1st law of thermodynamics
Term
What is the degree of siorganization of a systems total energy?
Definition
Entropy
Term
What principle state that the amount of entropy increases with each energy transormation?
Definition
The 2nd law of thermodynamics
Term
What are chemical reactions that require an input of energy?
Definition
Endergonic reactions
Term
What type of reactions release energy as they proceed?
Definition
Exergonic reactions
Term
What is the amount of heat required to raise the temperature of one gram (one cubic centimeter or one milliliter) one degree Celsius?
Definition
A calorie
Term
What unit of measure is usually used for foods?
Definition
the kilocalorie (Calorie)
Term
Coupled reactions involve what two types of reactions?
Definition
Exergonic and Endergonic
Term
The energy released by most exergonic reactions in the cell, either directly, or indirectly, drive the formation of what molecule?
Definition
Adenosine Triphosphate
Term
What is the full term for ATP?
Definition
Adenosine Triphosphate
Term
What is the universal energy carrier in living systems?
Definition
Adenosine Triphosphate
Term
What are the three things ATP is used for?
Definition
Biomechanical movement, Transportation, To make reactions go
Term
What is the reduction of a molecule?
Definition
The gaining of electrons
Term
What is the oxidation of a molecule?
Definition
The loss of electrons
Term
What is a molecule that donates electrons to another?
Definition
The reducing agent
Term
What is a molecule that accepts electrons?
Definition
The oxidizing agent
Term
Name two molecules that are important in transferring hydrogen from one molecule to another. They are coenzymes that act as hydrogen carriers.
Definition
Nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD)
Term
What are the reduced forms of NAD and FAD?
Definition
NADH + H+ & FADH2
Term
As entropy increases, what happens to the amount of energy available to do work?
Definition
It Decreases
Supporting users have an ad free experience!