ENZIM

Enzyme or biokatalisator is an organic catalyst produced by sel.Enzim very importantin life, because all metabolic reactions catalyzed by enzymes. If there is no enzyme, orenzyme activity disturbed the reaction cell metabolism is inhibited until the cell growthwas also disrupted

Enzymatic reactions required for the bacteria to obtain food and nutrients in adissolved state which can be absorbed into the cell, to obtain chemical energy used forbiosynthesis, proliferation, movement, and others.

1. Nomenklatur Enzim
Usually have the suffix-ase enzyme. In front of the substrate-ase used the name in which the enzyme works., or the name of the catalyzed reaction. For example:cellulase, dehydrogenase, urease, and others. But the naming of the above guidelinesare not always digunakann. This is due to the name used prior to the namingguidelines for acceptable and that name was in common use. For example pepsin,trypsin, and others. In the Glossary of Organic Chemistry (1978), the suffix-ase isreplaced with despair.

2. Struktur Enzim
At first considered only enzyme composed of proteins and enzymes that indeed therewas only composed of protein alone. For example, pepsin and tripsin.Tetapi there areenzymes that in addition to proteins also require components other than protein.Components other than the enzyme called protein cofactors. Coenzyme to a metal ion /metal, or organic molecules called coenzymes. The combination of the protein enzyme(apoenzim) and cofactor called holoenzim.

Enzymes that require metal ions as kofaktornya called metaloenzim .. Metal ion servesto be a primary catalyst center, a place to bind substrate, and a stabilizer so that the enzyme remains active.

Table1. Several enzymes that contain metal ions as kofactor


Ion logam
Enzim
Zn 2+



Mg2+


Fe2+ / Fe3+




Cu2+/ Cu+


K+

Na+


Alcohol dehidrogenase
Karbonat anhidrasa
Karboksipeptidasa

Fosfohidrolasa
Fosfotransferasa

Sitokrom
Peroksida
Katalasa
Feredoksin

Tirosina
Sitokrom oksidasa

Piruvat kinasa (juga memerlukan Mg2+)

Membrane sel ATPasa ( juga memerlukan K+ dan Mg2+)





3. Enzim Aktivity
As with any catalyst, enzymes can accelerate chemical reactions by lowering theactivation energy. This enzyme will join while the reactants so as to achieve a state of transition with a lower activation energy than the activation energy required to reach thetransition state without the help of a catalyst or enzyme.


4. Enzim Hidrolase
Hidrolase are enzymes that help describe a substance with water. Hidrolase divided into small groups based on the substrate, namely:

A. Carbohydrases, ie enzymes that describes the type of carbohydrate.

This group was split again according to the diuraikannya carbohydrates, for example:
a. Amylase, an enzyme which describes starch (a polysaccharide) into maltose 9 adisaccharide).

b. Maltase, an enzyme which describes the maltose into glucose

c. Sukrase, the enzyme that converts sucrose (cane sugar) into glucose and fructose.

d. Lactase, the enzyme that converts lactase into glucose and galactose.

e. Cellulase, which describes emzim cellulose (a polysaccharide) into ellobiose (adisaccharide)

f. Pektinase, an enzyme which describes the acid-pectin pectin.

B. Esterase, ie the enzymes that break down the ester group.

Examples:
a. Lipase, an enzyme which describes the fat into glycerol and fatty acids.
b. Phosphatase, an enzyme which describes a phosphoric acid ester to release it.

C. Proteinase or protease, an enzyme which describes the class of enzyme protein.

Examples:
a. Peptidase, an enzyme which describes peptides into amino acids.
b. Gelatinase, an enzyme which describes the gelatin.
c. Renin, an enzyme which describes the casein from milk.
Oxidase and reductase, namely enzime who helped in the process of oxidation and reduction.


Oxidase subdivided into;
a. Dehydrogenase: the enzyme plays an important role in converting organic substancesinto the results of oxidation.
b. Catalase: an enzyme that describes the hydrogen peroxide into water and oxygen.
Desmolase, ie enzymes that decide the bonds CC, CN and some other bonds.

Enzyme Desmolase subdivided into:
a. Carboxylase: an enzyme that converts piruyat acid to acetaldehyde.

b. Transaminase: an enzyme that removes the amine group of an amino acid 

into anorganic acid so that the latter is transformed into an amino acid.
Enzymes also can be differentiated into eksoenzim and endoenzim based on his workplace, in terms of cell membentuknya.Eksoenzim enzyme whose activity isoutside the cell. Endoenzim is an enzyme whose activity in the cell.
Besides eksoenzim and endoenzim, also known as constitutive enzymes and enzymeinductive. Constitutive enzyme is an enzyme that is formed continuously by the cellsubstrates regardless of whether there is or not. Inductive enzyme (enzyme adaptive) isan enzyme that is formed due to the stimulation of certain substrates or othercompounds. For example, the formation of beta-galaktosida enzyme in Escherichiacoli induced by lactose as the substrate. But there are other compounds that caninduce this enzyme, although not a substarnya, namely melibiosa. In the absence oflactose or melibiosa, the enzyme beta-galaktosidasa not synthesized, but synthesisbegins when added lactose or melibiosa.

5. Coenzyme
In his role, enzymes often need specific organic compounds other than proteins.Judging from the function, known as a coenzyme that acts as a hydrogen transfer,electron transfer, handling a particular chemical group ("group transferring") and a coenzyme from isomerasa and liasa.


Table 2. Examples of coenzymes and its role
No
Kode
Singkatan dari
Yang dipindahkan
1.
NAD
Nikotinamida-adenina dinukleotida
Hidrogen
2.
NADP
Nikotinamida-adenina dinukleotida fosfat
Hidrogen
3.
FMN
Flavin mononukleotida
Hidrogen
4.
FAD
Flavin-adenina dinukleotida
Hidrogen
5.
Ko-Q
Koenzim Q atau Quinon
Hidrogen
6.
sit
sitokrom
Elektron
7.
Fd
Ferredoksin
Elektron
8.
ATP
Adenosina trifosfat
Gugus fosfat
9.
PAPS
Fosfoadenil sulfat
Gugus sulfat
10.
UDP
Uridina difosfat
Gula
11.
Biotin
Biotin
Karboksil (CO2)
12.
Ko-A
Koenzim A
Asetil
13.
TPP
Tiamin pirofosfat
C2-aldehida
           


REFERENCES

 Dwidjoseputro,  Fundamentals of Microbiology
Timotius, K.H, 1982,  Basic Microbiology; Salatiga, Christian Universit Satya Wacana

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