Friday, 22 March 2013

BIO: BIOCATALYST SEM 2 MATRICULATION [1]

CHARACTERISTICS OF ENZYME:

.specific to its substrate only
.require in small amount
.reuseable
.reduce the activation energy
.speed up the reaction
.doen not alter its shape after reaction take place
.made up of globular protein: coding by dna
.can be affect by extreme temperature, ph, concentration of subtrate and enzyme.

MECHANISM OF ENZYME REACTION

consist of LOCK AND KEY HYPOTHESIS and INDUCED FIT MECHANISM

LOCK AND KEY.
1)substrate bind to the active site of the enzyme
2)enzyme-subsrate complex
3)weak ionic and hydrogen bond will stay at it position in the subsrate
4)r-chain of the active site will catalyst by stressing and stretching the molecules of subsrate so the chemical bond of the substrate broken
5)lower the activtion energy to break the bond
6)the product disattached from enzyme.

INDUCED-FIT MECHANISM
1)substrate bind to the active site of the enzyme
2)enzyme alter it shape so it fit well to subsrate molecule
3)enzyme-substrate complex
4)weak bond and hydrogen bond will be held the subtrate to the active site of the enzyme.
5)active site (r-chain)will stressing and stretching the molecule of substrate in order to break the bond that hold the substrate molecules.
6)activation energy lowered
7)the product disattached from the enzyme.

FACTORS AFFECTING THE ENZYME ACTION

I) ph
II) temperature
III) concentration of substrate
IV) concentration of enzyme

I) PH
.in the lower ph, acidity is reduced and the concentration of H+ ion increase. this will disrupt the ionic bond of the enzyme. active site are no longer productive to catalyst the subsrate. rate of reaction decreased.
.in the higher ph, basidity increase resulting in increasing of hydroxyl ion (OH-) also disrupt the ionic bond of the enzyme, active site are no longer productive to catalyst the substrate. rate of reaction decreased.

II) TEMPERATURE
.at 0'c, enzyme did not denatured but inactive.
.at optimum, rate of reaction is highest
.above 40'c, rate of reaction decreased. enzyme denatured.
" as increasing temperture, the collisin of the enzyme and subsrate increase. but higher temperature above the optimum temperature will resulting in decreased of rate of reaction. too high of kinetic energy will break the bond the hold the 1st,2nd,3rd and 4th structure of the protein. shape of the active site and enzyme itself would change and the active site of the enzyme are no longer fit with the subsrate. rate of reaction decrease sharply and finally no reaction occurs."
.after denatured the enzyme would never returnable.
.increasing temperature every 10'c will doubled the rate of reaction (below 40'c)

III) CONCENTRATION OF THE SUBSTRATE
.the rate of reaction increase until the point where enzyme are saturated with subsrate.
rate of reaction remain constant.
.the substrate has to wait for the enzyme to finish its reaction so it can bind to the enzyme.

IV) CONCENTRATION OF THE ENZYME
.rate of the reaction increased until there are the limiting substrate molecule left for the reaction.
.there are no other way to increase the rate of reaction. only increase the concentration of subsrate will increase the rate of reaction.

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