chapter 4 - enzyme
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CHAPTER 4:
CHEMICAL COMPOSITION
OF THE CELL
Prepared By: Miss Fatimah SaniUNIMAS Biotechnology Resources
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INTRODUCTION
The sum of all chemical reactions within a living
organism is known as metabolism
Metabolic pathways - series of chemicalreactions in which the product of one reaction
is the substrate for the next reaction. The chemical reactions are catalyzed by
enzymes, so the metabolic pathways present inan organism depend on the enzymes present in
the organism.
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METABOLISM
ANABOLISM
Simpler substancesare combined to
form more complexmolecules
Require energy
CATABOLISM
Breakdown of morecomplex organicmolecules into
simpler substances
Release energy
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ENZYMES(general
characteristics)
Proteins
Biologicalcatalysts
Needed insmall
amounts
Notchanged or
destroyed
Highlyspecific
Requirecofactors
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ENZYMES Enzymes are __________ which ______ the rate of
biochemical reactions in the body.
Highly ______.
Catalyze only a single reaction or one kind ofsubstrate
Specific site (______- which only bind to specificsubstrate)
Can be inhibited by ______
Require cofactors to function
Needed in minute amounts
Enzyme names usually end in ase (eg: lactase)
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Enzymes are biological catalyst which increase therate of biochemical reactions in the body.
Highly specific.
Catalyze only a single reaction or one kind ofsubstrate
Specific site (active site - which only bind tospecific substrate)
Can be inhibited by inhibitors
Require cofactors to function
Needed in minute amounts
Enzyme names usually end in ase (eg: lactase)
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INTRACELLULARENZYME
Produced andretained in
the cell itself
EXTRACELLULARENZYME
Secreted from
the cell
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MECHANISM OF ENZYME REACTION
An enzyme has a cleft
in its surface calledthe active site
In the lock and keytheory, the substrate
(key) fits into theactive site of theenzyme (lock)producing enzyme-
substrate complex
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ENZYME-SUBSTRATE COMPLEX
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ENZYME-SUBSTRATE COMPLEX
The substance
(reactant) anenzyme acts onis the substrate
EnzymeSubstrate Joins
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ENZYME-SUBSTRATE COMPLEX
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ACTIVE SITE A restricted region of an enzyme
molecule which binds to the substrate.
EnzymeSubstrate
ActiveSite
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WHAT AFFECTS ENZYME ACTIVITY?
FactorsEffects to the
enzymeGraph
pH
Optimum pH Fastreaction
Extreme pH(acidic/alkaline) no
reaction
Temperature
Reaction decrease /
slow Increase ( reach
optimum temp.)Beyond the optimum
temperature denatured (irreversible)
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FactorsEffects to the
enzymeGraph
Substrate concentration
Reaction rate increases in
direct proportion to the
substrate concentration
Enzyme concentration
Reaction rate increases in
direct proportion to the
enzyme concentration until
maximum rate is achieved
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THE USES OF ENZYME IN DAILY LIFE
Type of industry/application
Enzyme used Uses
Food processingEg: meat products
Textile products
Detergentmanufacturing