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Enzyme

Ribbon diagram of the catalytically perfect enzyme TIM.

Factor D enzyme crystal prevents the immune system from inappropriately runningout of control.

An enzyme (from Greeknsimo (), formed by n = at or in and simo = leaven

oryeast) is aprotein that catalyzes, or speeds up, a chemical reaction.

Enzymes are essential to sustain life, because most chemical reactions in biological

cells would occur too slowly or would lead to different products without enzymes. A

malfunction (mutation, overproduction, underproduction or deletion) of a single

critical enzyme can lead to severe diseases. For example, phenylketonuria is caused

by an enzyme malfunction in the enzyme phenylalanine hydroxylase, which catalyses

the first step in the degradation of phenylalanine. If this enzyme does not function, theresulting build-up of phenylalanine leads to mental retardation.

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Like all catalysts, enzymes work by lowering the activation energy of a reaction, thus

allowing the reaction to proceed much faster. Enzymes may speed up reactions by a

factor of many thousands. An enzyme, like any catalyst, remains unaltered by the

completed reaction and can therefore continue to function. Because enzymes, like all

catalysts, do not affect the relative energy between the products and reagents, they do

not affect equilibrium of a reaction. However, the advantage of enzymes compared tomost other catalysts is their sterio-, regio- and chemoselectivity and specificity.

Enzyme activity can be affected by other molecules. Inhibitors are molecules that

decrease or abolish enzyme activity; activators are molecules that increase the

activity. Suicide inhibitors are inhibitors that incorporate themselves into the enzyme,permanently deactivating it. Inhibitors can be either natural or man-made. Many drugs

are enzyme inhibitors. Aspirin, for example, inhibits an enzyme that produces the

inflammation messengerprostaglandin, thus suppressing pain and inflammation.

Enzymes are also used in everyday products such as washing detergents, where they

speed up chemical reactions involved in cleaning the clothes (for example, breakingdown starch stains). For industrial purposes the properties of Enzymes are emulated to

form new kinds of catalytic molecules named Synzymes and Abzyme.

More than 5,000 enzymes are known. To name different enzymes, one typically uses

the ending -ase with the name of the chemical being transformed (substrate), e.g.,

lactase is the enzyme that catalyzes the cleavage oflactose.

Etymology and history

Eduard Buchner

The word enzyme comes from Greek: "in leaven". As early as the late-1700s and

early-1800s, the digestion ofmeat by stomach secretions and the conversion of starch

to sugars by plant extracts and saliva were observed.

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Studying the fermentation of sugar to alcohol by yeast, Louis Pasteur came to the

conclusion that this fermentation was catalyzed by "ferments" in the yeast, which

were thought to function only in the presence of living organisms.

In 1897,Hans and Eduard Buchnerinadvertently used yeast extracts to ferment sugar,

despite the absence of living yeast cells. They were interested in making extracts ofyeast cells for medical purposes, and, as one possible way of preserving them, they

added large amounts of sucrose to the extract. To their surprise, they found that the

sugar was fermented, even though there were no living yeast cells in the mixture. The

term "enzyme" was used to describe the substance(s) in yeast extract that brought

about the fermentation of sucrose. An example of an enzyme would be amylase

3D-Structure

In enzymes, as with otherproteins, function is determined by structure. An enzyme

can be:

A monomeric protein, i.e., containing only one polypeptide chain, made up of

about hundred amino acids or more; or

an oligomeric protein consisting of several polypeptide chains, different or

identical, that act together as a unit.

As with any protein, each monomer is actually produced as a long, linear chain of

amino acids, which folds in a particular fashion to produce a three-dimensional

product. Individual monomers may then combine via non-covalent interactions toform a multimeric protein.

Cartoon showing the active site of an enzyme.

Most enzymes are far larger molecules than the substrates they act on and that only a

very small portion of the enzyme, around 10 amino acids, come into direct contact

with the substrate(s). This region, where binding of the substrate(s) and than the

reaction occurs, is known as the active site of the enzyme. Sometimes enzymes

contain additionally other binding sites. Some enzymes have a binding site for a

cofactor, which is needed for catalysis. Some enzymes have a binding site that serveregulatory functions, which increase or decrease the enzyme's activity. These

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typically bind small molecules, often direct or indirect products or substrates of the

reaction catalyzed. This provides a means forfeedbackregulation.

The amino acid sidechains of an enzyme are either involved in forming the active site

or a binding site, or are needed to form the 3D-structure of the protein. Some amino

acid sidechains are not needed for function or structure of the enzyme.

Specificity

Enzymes are usually specific as to the reactions they catalyze and the substrates that

are involved in these reactions. Shape and charge complementarity of enzyme and

substrate are responsible for this specificity.

"Lock and key" hypothesis

Fischer's lock and key hypothesis of enzyme action.

Enzymes are very specific and it was suggested by Emil Fischerin 1890 that this was

because the enzyme had a particular shape into which the substrate(s) fit exactly. This

is often referred to as "the lock and key" hypothesis. An enzyme combines with its

substrate(s) to form a short lived enzyme-substrate complex.

Induced fit hypothesis

Diagrams to show Koshland's induced fit hypothesis of enzyme action.

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In 1958 Daniel Koshland suggested a modification to the "lock and key" hypothesis.

Enzymes are rather flexible structures. The active site of an enzyme could be

modified as the substrate interacts with the enzyme. The amino acids sidechains

which make up the active site are molded into a precise shape which enables the

enzyme to perform its catalytic function. In some cases the substrate molecule

changes shape slightly as it enters the active site.

A suitable analogy would be that of a hand changing the shape of a glove as the glove

is put on.

Modifications

Many enzymes contain not only a protein part but need additionally various

modifications. These modifications are made posttranslational, i.e. after thepolypeptide chain was synthesized. Additional groups can be synthesized onto thepolypeptide chain. E.g.phosphorylation orglycolisation of the enzyme.

Another kind of posttranslational modification is the cleavage and splicing of the

polypeptide chain. E.g. chymotrypsin, a digestive protease, is produced in inactive

form as chymotrypsinogen in the pancreas and transported in this form to the stomach

where it is activated. This prevents the enzyme from harmful digestion of the pancreas

or other tissue. This type of inactive precursor to an enzyme is known as a zymogen.

Enzyme cofactors

Some enzymes do not need any additional components to exhibit full activities.

However, many enzymes are chemically inactive, and they require additional

components to become active. An enzyme cofactor is the non-protein component of

an enzyme essential for its catalytic activity. There are three types of cofactors,

namely activators, coenzymes,prosthetic groups.

Activators

Certain enzymes require inorganicions as cofactors. These inorganic ions are called

activators. They are mainly metallic monovalent or divalent cations which are either

loosely or firmly bound to the enzymes. For example in blood clotting, calcium ions,

known as factor IV, are required to activate thrombokinase to convert prothrombin

into thrombin.

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Prosthetic groups

Structure ofheme.

Non-protein organic cofactors which are firmly bound to the enzyme molecules are

called prosthetic groups. They combine to form an integral part in performing

catalytic functions. FAD, a prosthetic group containing heavy metals, is a prosthetic

group having similar function as NAD and NADP in carrying hydrogen. Heme is a

prosthetic group responsible for carring electrons in the cytochrome system.

Coenzymes

The cofactors of some other enzymes are non-protein organic molecules known as

coenzymes, which are not bonded to enzyme molecules like prosthetic groups. Being

vitamin-derivatives, they usually serve as carriers to transfer atoms or functional

groups from one enzyme to a substrate. Common examples are NAD (derived from

nicotinic acid, a member ofvitamin B complex) andNADP, which act as hydrogen

carriers and Coenzyme A that transfers the acetyl groups.

Those inactive protein parts of enzymes are called apoenzymes. An apoenzyme works

effectively only in the presence of non-protein cofactors. An apoenzyme together with

its cofactor constitutes a holoenzyme, i.e., an active enzyme. Most of the cofactors are

either regenerated or chemically unchanged at the end of the reactions.

Allosteric modulation

Allosteric enzymes have eithereffectorbinding sites, or multipleprotein subunits thatinteract with each other and thus influence catalytic activity.

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Kinetics

In 1913, Leonor Michaelis and Maud Menten proposed a quantitative theory of

enzyme kinetics which is still widely used today (usually referred to as Michaelis-

Menten kinetics). Enzymes can perform up to several million catalytic reactions per

second; to determine the maximum speed of an enzymatic reaction, the substrate

concentration is increased until a constant rate of product formation is achieved. This

is the maximum velocity (Vmax) of the enzyme. In this state, all enzyme active sites aresaturated with substrate. However, Vmax is only one kinetic parameter that biochemists

are interested in. The amount of substrate needed to achieve a given rate of reaction is

also of interest. This can be expressed by the Michaelis-Menten constant (KM), which

is the substrate concentration required for an enzyme to reach one half its maximum

velocity. Each enzyme has a characteristicKM for a given substrate. Since Vmax cannotbe measured directly, bothKM and Vmax are usually determined by extrapolating from

a limited data set, using what is known as a double reciprocal, or Lineweaver-Burk

plot.

The efficiency of an enzyme can be expressed in terms of kcat/Km. The quantity kcat,

also called the turnover number, incorporates the rate constants for all steps in the

reaction, and is the product of Vmax and the total enzyme concentration. kcat/Km is a

useful quantity for comparing different enzymes against each other, or the same

enzyme with different substrates, because it takes both affinity and catalytic ability

into consideration. The theoretical maximum for kcat/Km, called diffusion limit, is

about 108 to 109 (l mol-1 s-1). At this point, every collision of the enzyme with its

substrate will result in catalysis and the rate of product formation is not limited by the

reaction rate but by the diffusion rate. Enzymes that reach this kcat/Km value are called

catalytically perfect or kinetically perfect. Example of such enzymes are triose-phosphate isomerase,carbonic anhydrase, acetylcholinesterase, catalase, fumarase, -

lactamase, and superoxide dismutase.

Thermodynamics

Diagram of a catalytic reaction, showing the energy niveau at each stage of the

reaction. The substrates (A and B) usually need a large amount of energy to reach the

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transition state (TS), which then reacts to form the end product (C and D). The

enzyme stabilizes the transition state, reducing the energy niveau of the transition

state and thus the energy required to get over this barrier. Because the lower energy

niveau is easier to reach and therefore occurs more frequently, the reaction is more

likely to take place, thus increasing the reaction speed.

As with all catalysts, all reactions catalyzed by enzymes must be "spontaneous"

(containing a net negative Gibbs free energy). With the enzyme, they run in the same

direction as they would without the enzyme, just more quickly. However, the

uncatalyzed, "spontaneous" reaction might lead to different products than the

catalyzed reaction. Furthermore, enzymes can couple two or more reactions, so that a

thermodynamically favorable reaction can be used to "drive" a thermodynamically

unfavorable one. For example, the cleavage of the high-energy compound ATP is

often used to drive other, energetically unfavorable chemical reactions.

Many reactions catalyzed by an enzyme are reversible.

Enzymes catalyze the forward and backward reactions equally. They do not alter the

equilibrium itself, but only the speed at which it is reached, for example, carbonic

anhydrase which catalyzes a reaction in either direction depending on the conditions

at the time.

(in tissues - high CO2concentration)

(in lungs - low CO2concentration)

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Inhibition

Enzymes reaction rates can be changed by competitive inhibition, non-competitive

inhibition, uncompetitive inhibition and mixed inhibition.

Competitive inhibition

Competitive inhibition. A competitive inhibitor binds reversibly to the enzyme,

preventing the binding of substrate. On the other hand, binding of substrate prevents

binding of the inhibitor, thus substrate and inhibitor compete for the enzyme.

The inhibitor may bind to the substrate binding site as shown in the figure above, thus

preventing substrate binding. An example for competitive inhibition is the enzyme

succinate dehydrogenase by malonate. Succinate dehydrogenase catalyses the

oxidation ofsuccinate to fumarate.

Action of the enzyme succinate dehydrogenase on succinate (right) and competitive

inhibition of the enzyme by malonate (bottom).

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Uncompetitive inhibition

Uncompetitive inhibition occurs when the inhibitor binds only to the enzyme-

substrate complex, not to the free enzyme, the enzyme-inhibitor-substrate (EIS)

complex is catalytically inactive. This mode of inhibition is rare.

Non-competitive inhibition

Diagram showing the mechanism of non-competitive inhibition.

Non-competitive inhibitors never bind to the active center, but to other parts of the

enzyme that can be far away from the substrate binding site, consequently, there is no

competition between the substrate and inhibitor for the enzyme. The extent of

inhibition depends entirely on the inhibitor concentration and will not be affected by

the substrate concentration. However, these inhibitors bind only loosely with the

enzyme and can be removed to resume the enzymatic activities. For example, cyanide

combines with the copperprosthetic groups of the enzyme cytochrome c oxidase, thus

inhibiting respiration.

By changing the conformation (the three-dimensional structure) of the enzyme, the

inhibitors either disable the ability of the enzyme to bind or turn over its substrate.

The EI and EIS-complex have no catalytic activity.

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Partially competitive inhibition

The mechanism of partially competitive is similar to that of non-competitive

inhibition, except that the EIS-complex has catalytic activity, which may be lower or

even higher (partially competitive activation) than that of the ES-complex.

Irreversible inhibitors

Some inhibitor bind irreversibly with the enzyme molecules, inhibiting the catalytic

activities permanently. The enzymatic reactions will stop sooner or later and are not

affected by an increase in substrate concentration. These are irreversible inhibitors.

Examples are heavy metal ions including silver,mercury and lead ions.

Another example of irreversible inhibition is provided by the nerve gasdiisopropylfluorophosphate (DFP) designed for use in warfare. It combines with the

amino acid serine (contains the SH group) at the active site of the enzyme

acetylcholinesterase. The enzyme deactivates the neurotransmitter acetylcholine.

Neurotransmitters are needed to continue the passage of nerve impulses from one

neurone to another across the synapse. Once the impulse has been transmitted,

acetylcholinesterase functions to deactivate the acetycholine almost immediately by

breaking it down. If the enzyme is inhibited, acetylcholine accumulates and nerve

impulses cannot be stopped, causing prolonged muscle contration. Paralysis occurs

and death may result since the respiratory muscles are affected. Some insecticides

currently in use, including those known as organophosphates (e.g.parathion), have a

similar effect on insects, and can also cause harm to nervous and muscular system ofhumans who are overexposed to them.

Metabolic pathways and allosteric enzymes

Several enzymes can work together in a specific order, creating metabolic pathways.

In a metabolic pathway, one enzyme takes the product of another enzyme as a

substrate. After the catalytic reaction, the product is then passed on to another

enzyme. The end product(s) of such a pathway are often inhibitors for one of the firstenzymes of the pathway (usually the first irreversible step, called committed step),

thus regulating the amount of end product made by the pathways. Such a regulatory

mechanism is called a negative feedback mechanism, because the amount of the end

product produced is regulated by its own concentration. Negative feedback

mechanism can effectively adjust the rate of synthesis of intermediate metabolites

according to the demands of the cells. This helps with effective allocations of

materials and energy economy, and it prevents the excess manufacture of end

products. Like other homeostatic devices, the control of enzymatic action helps to

maintain a stable internal environment in living organisms.

http://en.wikipedia.org/wiki/Silver_(element)http://en.wikipedia.org/wiki/Mercury_(element)http://en.wikipedia.org/wiki/Lead_(element)http://en.wikipedia.org/wiki/Nerve_gashttp://en.wikipedia.org/w/index.php?title=Diisopropylfluorophosphate&action=edithttp://en.wikipedia.org/wiki/Warfarehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Serinehttp://en.wikipedia.org/wiki/Acetylcholinesterasehttp://en.wikipedia.org/wiki/Neurotransmitterhttp://en.wikipedia.org/wiki/Acetylcholinehttp://en.wikipedia.org/wiki/Nerve_impulsehttp://en.wikipedia.org/wiki/Neuronehttp://en.wikipedia.org/wiki/Synapsehttp://en.wikipedia.org/wiki/Paralysishttp://en.wikipedia.org/wiki/Deathhttp://en.wikipedia.org/wiki/Diaphragmhttp://en.wikipedia.org/wiki/Insecticideshttp://en.wikipedia.org/wiki/Organophosphatehttp://en.wikipedia.org/wiki/Parathionhttp://en.wikipedia.org/wiki/Nervous_systemhttp://en.wikipedia.org/wiki/Muscular_systemhttp://en.wikipedia.org/wiki/Humanhttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Inhibitorshttp://en.wikipedia.org/wiki/Negative_feedbackhttp://en.wikipedia.org/wiki/Homeostasishttp://en.wikipedia.org/wiki/Silver_(element)http://en.wikipedia.org/wiki/Mercury_(element)http://en.wikipedia.org/wiki/Lead_(element)http://en.wikipedia.org/wiki/Nerve_gashttp://en.wikipedia.org/w/index.php?title=Diisopropylfluorophosphate&action=edithttp://en.wikipedia.org/wiki/Warfarehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Serinehttp://en.wikipedia.org/wiki/Acetylcholinesterasehttp://en.wikipedia.org/wiki/Neurotransmitterhttp://en.wikipedia.org/wiki/Acetylcholinehttp://en.wikipedia.org/wiki/Nerve_impulsehttp://en.wikipedia.org/wiki/Neuronehttp://en.wikipedia.org/wiki/Synapsehttp://en.wikipedia.org/wiki/Paralysishttp://en.wikipedia.org/wiki/Deathhttp://en.wikipedia.org/wiki/Diaphragmhttp://en.wikipedia.org/wiki/Insecticideshttp://en.wikipedia.org/wiki/Organophosphatehttp://en.wikipedia.org/wiki/Parathionhttp://en.wikipedia.org/wiki/Nervous_systemhttp://en.wikipedia.org/wiki/Muscular_systemhttp://en.wikipedia.org/wiki/Humanhttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Inhibitorshttp://en.wikipedia.org/wiki/Negative_feedbackhttp://en.wikipedia.org/wiki/Homeostasis

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http://en.wikipedia.org/wiki/Image:Feedback_inhibition.png

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Common feedback inhibition mechanisms, (1) The basic feedback inhibition

mechanism, where the product (P) inhibits the committed step (AB). (2) Sequentialfeedback inhibition. The end products P1 and P2 inhibit the first committed step oftheir individual pathway (CD or CF). If both products are present in abundance,

all pathways from C are blocked. This leads to a buildup of C, which in turn inhibitsthe first common committed step AB. (3) Enzyme multiplicity. Each end productinhibits both the first individual committed step and one of the enzymes performing

the first common committed step. (4) Concerted feedback inhibition. Each endproduct inhibits the first individual committed step. Together, they inhibit the first

common committed step. (5) Cumulative feedback inhibition. Each end product

inhibits the first individual committed step. Also, each end productpartially inhibitsthe first common committed step.

Enzymes that are regulated by end-production inhibition are usually allosteric

enzymes. An allosteric enzyme molecule has an active site and also an allosteric site.

The allosteric site can bind with allosteric effectors that affect the activity of theenzyme molecule. Allosteric effectors include allosteric activators and allosteric

inhibitors. The binding with an allosteric activator activates an enzyme molecule

because the active site is in the right conformation to bind with substrate molecules.

The binding with an allosteric inhibitor inactivates the enzyme molecule because the

conformation of the active site is altered. The activation and inhibition of an allosteric

enzyme are reversible.

Allosteric inhibition. In the example ATCase, the enzyme of the first reaction in the

pathway, is an allosteric enzyme, and CTP, the end product, is an allosteric inhibitor

of ATCase.

http://en.wikipedia.org/wiki/ATCasehttp://en.wikipedia.org/wiki/CTPhttp://en.wikipedia.org/wiki/Image:Allosteric_inhibition.pnghttp://en.wikipedia.org/wiki/ATCasehttp://en.wikipedia.org/wiki/CTP

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Enzyme naming conventions

By common convention, an enzyme's name consists of a description of what it does,

with the word ending in -ase. Examples are alcohol dehydrogenase and DNA

polymerase. Kinases are enzymes that transferphosphate groups. This results in

different enzymes with the same function having the same basic name; they are

therefore distinguished by other characteristics, such their optimal pH (alkaline

phosphatase) or their location (membrane ATPase). Furthermore, the reversibility of

chemical reactions means that the normal physiological direction of an enzyme's

function may not be that observed under laboratory conditions. This can result in the

same enzyme being identified with two different names: one stemming from the

formal laboratory identification as described above, the other representing its behavior

in the cell. For instance the enzyme formally known as xylitol:NAD+ 2-

oxidoreductase (D-xylulose-forming) is more commonly referred to in the cellular

physiological sense asD-xylulose reductase, reflecting the fact that the function of the

enzyme in the cell is actually the reverse of what is often seen under in vitroconditions.

The International Union of Biochemistry and Molecular Biology has developed a

nomenclature for enzymes, the EC numbers; each enzyme is described by a sequence

of four numbers, preceded by "EC". The first number broadly classifies the enzyme

based on its mechanism:

Group Reaction catalyzedTypical

reaction

Enzyme

example(s) with

trivial name

EC 1

Oxidoreductases

To catalyze oxidation/reduction

reactions; transfer of H and Oatoms or electrons from one

substance to another

AH + B A

+ BH(reduced)

A + O AO

(oxidized)

Dehydrogenase,

oxidase

EC 2

Transferases

Transfer of a functional group

from one substance to another.

The group may be methyl-,

acyl-, amino- or phospate group

AB + C A

+ BC

Transaminase,

kinase

EC 3

Hydrolases

Formation of two products from

a substrate by hydrolysis

AB + H2O

AOH + BH

Lipase, amylase,

peptidase

EC 4

Lyases

Non-hydrolytic addition or

removal of groups from

substrates. C-C, C-N, C-O or C-

S bonds may be cleaved

RCOCOOH

RCOH +

CO2

EC 5

Isomerases

Intramolecule rearrangement,

i.e. isomerization changes

within a single molecule

AB BA Isomerase, mutase

EC 6

Ligases

Join together two molecules by

synthesis of new C-O, C-S, C-N

or C-Cbonds with simultaneousbreakdown ofATP

X + Y+ ATP

XY + ADP

+ Pi

Synthetase

http://en.wikipedia.org/wiki/Alcohol_dehydrogenasehttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/Kinasehttp://en.wikipedia.org/wiki/Phosphatehttp://en.wikipedia.org/wiki/PHhttp://en.wikipedia.org/wiki/Alkaline_phosphatasehttp://en.wikipedia.org/wiki/Alkaline_phosphatasehttp://en.wikipedia.org/wiki/ATPasehttp://www.iubmb.unibe.ch/http://en.wikipedia.org/wiki/Nomenclaturehttp://en.wikipedia.org/wiki/EC_numberhttp://en.wikipedia.org/wiki/Oxidoreductasehttp://en.wikipedia.org/wiki/Oxidoreductasehttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Dehydrogenasehttp://en.wikipedia.org/wiki/Oxidasehttp://en.wikipedia.org/wiki/Transferasehttp://en.wikipedia.org/wiki/Functional_grouphttp://en.wikipedia.org/wiki/Transaminasehttp://en.wikipedia.org/wiki/Kinasehttp://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Hydrolysishttp://en.wikipedia.org/wiki/Lipasehttp://en.wikipedia.org/wiki/Amylasehttp://en.wikipedia.org/wiki/Peptidasehttp://en.wikipedia.org/wiki/Lyasehttp://en.wikipedia.org/wiki/Isomerasehttp://en.wikipedia.org/wiki/Isomerhttp://en.wikipedia.org/wiki/Isomerasehttp://en.wikipedia.org/w/index.php?title=Mutase&action=edithttp://en.wikipedia.org/wiki/Ligasehttp://en.wikipedia.org/wiki/Covalent_bondhttp://en.wikipedia.org/wiki/ATPhttp://en.wikipedia.org/wiki/Synthetasehttp://en.wikipedia.org/wiki/Alcohol_dehydrogenasehttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/Kinasehttp://en.wikipedia.org/wiki/Phosphatehttp://en.wikipedia.org/wiki/PHhttp://en.wikipedia.org/wiki/Alkaline_phosphatasehttp://en.wikipedia.org/wiki/Alkaline_phosphatasehttp://en.wikipedia.org/wiki/ATPasehttp://www.iubmb.unibe.ch/http://en.wikipedia.org/wiki/Nomenclaturehttp://en.wikipedia.org/wiki/EC_numberhttp://en.wikipedia.org/wiki/Oxidoreductasehttp://en.wikipedia.org/wiki/Oxidoreductasehttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Dehydrogenasehttp://en.wikipedia.org/wiki/Oxidasehttp://en.wikipedia.org/wiki/Transferasehttp://en.wikipedia.org/wiki/Functional_grouphttp://en.wikipedia.org/wiki/Transaminasehttp://en.wikipedia.org/wiki/Kinasehttp://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Hydrolysishttp://en.wikipedia.org/wiki/Lipasehttp://en.wikipedia.org/wiki/Amylasehttp://en.wikipedia.org/wiki/Peptidasehttp://en.wikipedia.org/wiki/Lyasehttp://en.wikipedia.org/wiki/Isomerasehttp://en.wikipedia.org/wiki/Isomerhttp://en.wikipedia.org/wiki/Isomerasehttp://en.wikipedia.org/w/index.php?title=Mutase&action=edithttp://en.wikipedia.org/wiki/Ligasehttp://en.wikipedia.org/wiki/Covalent_bondhttp://en.wikipedia.org/wiki/ATPhttp://en.wikipedia.org/wiki/Synthetase

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Applications

Application Enzymes used Uses Notes and examples

Biological

detergent

Primarily

proteases, produced

in an extracellular

form frombacteria

Used for

presoakconditions and

direct liquid

applications

helping with

removal of

protein stains

from clothes.

Biological washing powders contain protease.

Note: The amylases and proteases used in

detergents are allergenic for the process workers,although, encapsulation techniques have reduced

this problem.

Amylase enzymes

Detergents for

machine

dishwashing to

removeresistant starch

residues

Baking

industry

Fungal alpha-

amylase enzymes:

normally

inactivates about 50

degrees Celsius,

destroyed during

baking process

Catalyze

breakdown of

starch in the

flour to sugar.

Yeast action on

sugar produces

carbon dioxide.

Used in

production ofwhite bread,

buns, and rolls

alpha-amylase catalyzes the release sugar

monomers (n) from starch

Protease enzymes

Biscuit

manufacturers

use them to

lower the

protein level of

flour.

Baby foods TrypsinTo predigest

baby foods

Brewing

industry

Enzymes from

barley are released

during the mashing

stage of beer

production.

They degrade

starch and

proteins to

produce simple

sugar, amino

acids and

peptides that

are used by

yeast to

enhance

fermentation.

Germinating barley used for malt.

Industrially produced enzymes

http://en.wikipedia.org/wiki/Detergenthttp://en.wikipedia.org/wiki/Detergenthttp://en.wikipedia.org/wiki/Proteasehttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Bakinghttp://en.wikipedia.org/wiki/Bakinghttp://en.wikipedia.org/wiki/Fungushttp://en.wikipedia.org/wiki/Flourhttp://en.wikipedia.org/wiki/Baby_foodhttp://en.wikipedia.org/wiki/Trypsinhttp://en.wikipedia.org/wiki/Brewinghttp://en.wikipedia.org/wiki/Brewinghttp://en.wikipedia.org/wiki/Image:Sjb_whiskey_malt.jpghttp://en.wikipedia.org/wiki/Image:Amylose.gifhttp://en.wikipedia.org/wiki/Image:Washingpowder.jpghttp://en.wikipedia.org/wiki/Detergenthttp://en.wikipedia.org/wiki/Detergenthttp://en.wikipedia.org/wiki/Proteasehttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Bakinghttp://en.wikipedia.org/wiki/Bakinghttp://en.wikipedia.org/wiki/Fungushttp://en.wikipedia.org/wiki/Flourhttp://en.wikipedia.org/wiki/Baby_foodhttp://en.wikipedia.org/wiki/Trypsinhttp://en.wikipedia.org/wiki/Brewinghttp://en.wikipedia.org/wiki/Brewing

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now widely used in the brewing

process to substitute for the

natural enzymes found in barley:

Amylase,

glucanases,proteases

Split

polysaccharide

s and proteins

in the malt

Betaglucosidase

Improve the

filtration

characteristics.

AmyloglucosidaseLow-calorie

beer

Proteases

Remove

cloudiness

during storage

of beers.

Fruit juicesCellulases,

pectinases

Clarify fruit

juices

Dairy

industry

Rennin, derived

from the stomachs

of young ruminant

animals (calves,

lambs, kids)

Manufacture of

cheese, used to

split protein

Note: As animals age rennin production decreases

and is replaced by another protease, pepsin, which

is not suitable for cheese production. In recent years

the increase in cheese consumption, as well as

increased beef production, has resulted in a shortage

of rennin and escalating prices.

Microbiallyproduced enzyme

Now finding

increasing usein the dairy

industry

Roquefort cheese

Lipases

Is implemented

during the

production of

Roquefort

cheese to

enhance the

ripening of the

blue-mould

cheese.

Lactases

Break down

lactose to

glucose and

galactose

Starch

industry

Amylases,

amyloglucosidease

s and

glucoamylases

Converts starch

into glucose

and various

syrups

Glucose isomerase Converts

glucose infructose (high

http://en.wikipedia.org/wiki/Malthttp://en.wikipedia.org/wiki/Beerhttp://en.wikipedia.org/wiki/Juicehttp://en.wikipedia.org/wiki/Dairyhttp://en.wikipedia.org/wiki/Dairyhttp://en.wikipedia.org/wiki/Ruminanthttp://en.wikipedia.org/wiki/Ruminanthttp://en.wikipedia.org/wiki/Lipasehttp://en.wikipedia.org/wiki/Roquefort_cheesehttp://en.wikipedia.org/wiki/Roquefort_cheesehttp://en.wikipedia.org/wiki/Danish_Blue_cheesehttp://en.wikipedia.org/wiki/Danish_Blue_cheesehttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Inverted_sugar_syruphttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Image:Alpha-D-Fructose-structure-corrected.pnghttp://en.wikipedia.org/wiki/Image:Glucose.pnghttp://en.wikipedia.org/wiki/Image:Roquefort_cheese.jpghttp://en.wikipedia.org/wiki/Malthttp://en.wikipedia.org/wiki/Beerhttp://en.wikipedia.org/wiki/Juicehttp://en.wikipedia.org/wiki/Dairyhttp://en.wikipedia.org/wiki/Dairyhttp://en.wikipedia.org/wiki/Ruminanthttp://en.wikipedia.org/wiki/Ruminanthttp://en.wikipedia.org/wiki/Lipasehttp://en.wikipedia.org/wiki/Roquefort_cheesehttp://en.wikipedia.org/wiki/Roquefort_cheesehttp://en.wikipedia.org/wiki/Danish_Blue_cheesehttp://en.wikipedia.org/wiki/Danish_Blue_cheesehttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Starchhttp://en.wikipedia.org/wiki/Inverted_sugar_syruphttp://en.wikipedia.org/wiki/Glucose

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fructose syrups

derived from

starchy

materials have

enhanced

sweetening properties and

lower calorific

values)

Glucose Fructose

Immobilised

enzymes

Production of

high fructose

syrups

Note: Although this process is widely used in the

USA and Japan, legislation in the EEC restricts its

use to protect sugar beet farmers.

Rubber

industryCatalase

To generate

oxygen from

peroxide to

convert latex to

foam rubber

Paper

industryAmylases

Degrade starch

to lower

viscosity

product needed

for sizing and

coating paper

Paper factories use amylase

Photographic

industryProtease (ficin)

Dissolvegelatin off the

scrap film

allowing

recovery of

silverpresent

http://en.wikipedia.org/wiki/Caloriehttp://en.wikipedia.org/wiki/Caloriehttp://en.wikipedia.org/wiki/USAhttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/EEChttp://en.wikipedia.org/wiki/Sugar_beethttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Catalasehttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Peroxidehttp://en.wikipedia.org/wiki/Latexhttp://en.wikipedia.org/wiki/Paperhttp://en.wikipedia.org/wiki/Paperhttp://en.wikipedia.org/wiki/Amylasehttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Photographyhttp://en.wikipedia.org/wiki/Photographyhttp://en.wikipedia.org/wiki/Gelatinhttp://en.wikipedia.org/wiki/Photographic_filmhttp://en.wikipedia.org/wiki/Silverhttp://en.wikipedia.org/wiki/Image:InternationalPaper6413.JPGhttp://en.wikipedia.org/wiki/Image:InternationalPaper6413.JPGhttp://en.wikipedia.org/wiki/Caloriehttp://en.wikipedia.org/wiki/Caloriehttp://en.wikipedia.org/wiki/USAhttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/EEChttp://en.wikipedia.org/wiki/Sugar_beethttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Catalasehttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Peroxidehttp://en.wikipedia.org/wiki/Latexhttp://en.wikipedia.org/wiki/Paperhttp://en.wikipedia.org/wiki/Paperhttp://en.wikipedia.org/wiki/Amylasehttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Photographyhttp://en.wikipedia.org/wiki/Photographyhttp://en.wikipedia.org/wiki/Gelatinhttp://en.wikipedia.org/wiki/Photographic_filmhttp://en.wikipedia.org/wiki/Silver