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