Test 2 - Micro
speed up rate of uncatalyzed reaction
Enzymes are indispensable for life because they
Larger
Enzymes are typically _______ than substrates.
weakly
Enzymes bond ______ with their substrate.
apoenzymes
Exhibits primary, secondary, tertiary, and some, quaternary structure
bind to a cofactor
For an apoenzyme to become a functional holoenzyme it must
enzyme
Lowers the activation of energy required for a chemical reaction to proceed
cofactors
Metal ions, coenzymes, and vitamins are examples of
enzyme
Most are composed of protein; may require cofactors
induced fit
Slight changes occur in the shape of the enzyme in order to guide the substrate into the active site. This is referred to as a _______ ___.
Coenzyme
________ acts as a carrier to move a chemical group from one substrate molecule to another.
enzymes
________ acts as a catalyst in virtually all metabolic pathways.
Vitamins
________ are principle components of coenzymes and this is why they are important components of our diet.
cofactor
________ can be metals that activate enzymes and help bring the active site and substrate together
cofactor
________ is an organic molecule or inorganic element that may be required for an enzyme to become functional.
apoenzyme
_________ refers to a biological catalyst that lacks an essential cofactor.
catabolism
__________ refers to the decomposition of complex compounds during cellular metabolism usually with the release of energy.
catabolism
__________ refers to the decompostion of complex compounds during cellular metabolism usually with release of energy
sensitivity of enzymes
activity of an enzyme is influenced by the cell's enviornment, enzymes operate under temp, pH, and osmotic pressure of organism's habitat, when subjected to changes in organism's habitat they become unstable
enzyme
acts as organic catalysts to speed up the rate of cellular reactions
oxidase
adds electrons to oxygen
metabolism
all chemical and physical workings of a cell
constitutive enzymes
always present, always produced in equal amounts or at equal rates, regardless of the amount of substrate
catalyst
an enzyme acts as a biological _________ that alters the rate of a reaction without being changed by the reaction.
enzyme
are greatly affected by temp and ph
enzyme
are much larger in size than their substrates
enzyme
are not used up or permanently changed by the reaction
enzyme
associate closely with substrates but do not become integrated into the reaction products
enzymes
biological catalysts that increase the rate of chemical reaction by lowering the energy of activation
anabolism
biosynthesis; process that forms larger macromolecules from smaller molecules; requires energy input
Catalase
breaks down hydrogen peroxide
enzyme
can be recycled, thus function in extremely low concentrations
enzyme
can be regulated by feedback and genetic mechanisms
anabolism
cellular process of takin monomers of compounds and producing polymers
labile
chemically unstable enzymes
enzymes
composed principally of amino acids, ______ act as biological catalysts, facilitating metabolic activities of the cell
simple enzymes
consist of protein alone
holoenzymes (conjugated enzymes)
contain protein and nonprotein molecules
catabolism
degradative; breaks the bonds of larger molecules forming smaller molecules; releases energy
enzyme
enable metabolic reactions to proceed at a speed compatible with life
anabolic and catabolic reactions
enzymes serve as catalysts for
function of enzymes
facilitate metabolic pathways
enzyme
has unique characteristics such as shape, specificty, and function
simple
A ______ enzyme consists of a protein alone.
enzyme
A _______ is a biological catalyst.
conjugated
A __________ enzyme (or holoenzyme) consists of protein and non protein components.
apoenzyme
A biological catalyst that lacks an essential cofactor
ribozyme
A catalyst composed of RNA is called ________.
coenzyme
A complex organic molecule, often derived from vitamins, that acts in conjunction with an enzyme is known as ________.
catalyst
An enzyme acts as a biological _______ that alters the rate of a reaction with out being changed by the reaction.
conjugated enzyme
An enzyme with another molecule, such as a metal or vitamin cofactor, bound covalently to it.
holoenzyme
An enzyme with it's apoenzyme and cofactors is referred to as a __________ or a conjugated enzyme.
catalytic
An enzymes ______ site is unique for each substrate.
metalic cofactors
iron, copper, magnesium
protein
most enzymes are a functional type of
protein
most enzymes are a functional type of __________
regulated enzymes
not constantly present; production is turned on (induced) or turned off (repressed) in response to changes in the substrate concentration
coenzymes
organic molecules (vitamins)
appropriate reaction occurs
product is formed and released
Apoenzyme
protein portion of an enzyme
nitrate reductase
reduces nitrate to nitrite
active site
region of an enzyme where the substrate binds
endoenzymes
retained intracellularly and function there, most enzymes are endoenzymes
active site (catalytic site)
site for substrate binding
urease
splits urea into an ammonium ion
DNA polymerase complex
synthesis of DNA
metabolism
the combination of catabolic and anabolic reactions within a cell is termed _________.
catabolism
the decomposition of complex compounds during cellular metabolism
hexokinase
transfers phosphate to glucose
exoenzymes
transported extracellularly, where they break down large food molecules or harmful chemicals, cellulase, amylase, penicillinase
denaturation
weak bonds that maintain the shape of the apoenzyme are broken
create reactions
what can't enzymes do
proteins
what macromolecule can commonly act as a catalyst?
apoenzyme
A non functional enzyme which needs a cofactor is called a
substrate
A specific reactant acted upon by an enzyme
induced fit
A temporary enzyme-substrate union occurs when substrate moves into active site
folding to produce 3D structure
Aspect of an enzyme's structure gives rise to the specificity for it's substrate
RNA
Besides proteins what type of molecule has been shown to have a catalytic activity?
RNA
Besides proteins, which type of molecule has shown to have catalytic activity?
cofactors
Coenzymes, metal ions, and small organic molecules all represent
enzymes
Composed principally of amino acids, _________ act as biological catalysts, facilitating metabolic activities of the cell.
fermentation
In very rare instances of intoxication, yeast in the small intestine can convert dietary carbohydrates to alcohol, a situation called gut _________ syndrome.
Lock and key
Which model is sometimes used to describe enzyme-substrate interactions?
coenzyme
Often derived from vitamins, a ________ is a type of cofactor that will act in conjunction with an enzyme to carry out activity.
specificity
Protein folding determines the 3D shape in enzymes needed for their ___________ for a particular substrate.
enzyme
Provide an active site for target moelcules called substrates
active site
Region of an enzyme where the substrate binds best defines
substrate
The _____ is the term for a specific molecule on which an enzyme acts.
active
The ______ site is the region on an enzyme that binds the substrate.
weak
The bonds that form enzyme-substrate complexes are ____ and easily reversible.
catabolism
The decomposition of complex compounds during cellular metabolism
energy of activation
The minimum amount of energy required for a reaction to proceed
anabolism
The specific process of _________ incorporates nutrients into larger, complex structures through biosynthesis.
ready to "work" again
Typically once an enzyme performs a "job" it is
lowers
Typically the presence of enzymes ______ the activation energy for a reaction period.
cofactor
What is needed for an apoenzyme to be fully functional?
substrate
What name is given to the compound upon which an enzyme will act?
induced fit
When a substrate binds to an enzymes active site often an _______ ___ occurs which brings the substrate tightly within the active site pocket.
active site
Which feature of an enzyme is the "most" unique?
lock & key
Which model is sometimes used to describe enzyme substrate interactions?
energy of activation
the resistance to a reaction, which must be overcome for a reaction to proceed
anabolism
the specific process of ________ incorporates nutrients into larger, complex structures through biosynthesis
