BIOLOGY 2.4
EMILY KINZLER
, INTRACELLULAR ENZ
ENZYMES
Bio catalysts
EXTRACELLULAR ENZ each metabolic pathway is a series of consecutive reactions, every step
catalysed by a specific enz that produces a specific product
!
speed up metabolic reactions secreted from cell various reactants/intermediates act as substractes
unchanged at end of reaction, can be used again e.g. fungi release hydrolytic enz to digest metabolites - reactants, intermediates, products
small amt of catalyst can catalyse large amt amylase produced in salivary glands/small intestine lumen, digest starch to catabolic - metabolites broken down to smaller mols + release energy
turnover number - no of reactions a mol can catalyse per second maltose anabolic - energy used to synth larger mols from smaller ones
trypsin made in pancreas, acts in lumen, hydrolyses peptide bonds, catalase found in all living orgs - protects cells from damage by breaking down
optimum ph 7.5-8.5 hydrogen peroxide to water and oxygen
hydrogen peroxide is a byproduct of metabolic reactions + harmful
catalase has 4 pp chains + haem group w iron
fastest acting enz, high turnover no, 6 mil per second
in eukaryotes catalase found in peroxisomes (vesicles)
catalase used to help kill invading microbe
optimum ph of catalase is ph7, for others ph4-11
optimum temp for humans is 45c, others 90c
WHY SO REMARKABLE
chemical catalysts need high temp, increased pressure, extreme ph
"
enz speed up reactions at lower temps, neutral ph + normal pressure, so
can sustain life
enz more specific than chemical catalysts, dont make unwanted by
products + rarely make mistakes
cells can also reg their activity to needs
ENZYMES - BIOLOGICAL CATALYSTS
WHERE ENZ WORK
intra/extracellular
ENZ STRUCTURE DETERMINES FUNCTION
if the gene for coding an enz has a mutation then this affects formation of tertiary
structure
if enz deficient, then metabolic disorder occurs
enz catalyse formation of structural components like ligaments so can be harmful
ACTIVE SITE
enz r large mols
active site - indentation on surface of mol, shape complementary to subs
each enz highly specific as it can only catalyse reaction w specific subs
shape of active site can be altered by temp/ph
temp + ph alter bonds that hold tertiary structure
thus temp + ph can alter ability to catalyse
EMILY KINZLER
, INTRACELLULAR ENZ
ENZYMES
Bio catalysts
EXTRACELLULAR ENZ each metabolic pathway is a series of consecutive reactions, every step
catalysed by a specific enz that produces a specific product
!
speed up metabolic reactions secreted from cell various reactants/intermediates act as substractes
unchanged at end of reaction, can be used again e.g. fungi release hydrolytic enz to digest metabolites - reactants, intermediates, products
small amt of catalyst can catalyse large amt amylase produced in salivary glands/small intestine lumen, digest starch to catabolic - metabolites broken down to smaller mols + release energy
turnover number - no of reactions a mol can catalyse per second maltose anabolic - energy used to synth larger mols from smaller ones
trypsin made in pancreas, acts in lumen, hydrolyses peptide bonds, catalase found in all living orgs - protects cells from damage by breaking down
optimum ph 7.5-8.5 hydrogen peroxide to water and oxygen
hydrogen peroxide is a byproduct of metabolic reactions + harmful
catalase has 4 pp chains + haem group w iron
fastest acting enz, high turnover no, 6 mil per second
in eukaryotes catalase found in peroxisomes (vesicles)
catalase used to help kill invading microbe
optimum ph of catalase is ph7, for others ph4-11
optimum temp for humans is 45c, others 90c
WHY SO REMARKABLE
chemical catalysts need high temp, increased pressure, extreme ph
"
enz speed up reactions at lower temps, neutral ph + normal pressure, so
can sustain life
enz more specific than chemical catalysts, dont make unwanted by
products + rarely make mistakes
cells can also reg their activity to needs
ENZYMES - BIOLOGICAL CATALYSTS
WHERE ENZ WORK
intra/extracellular
ENZ STRUCTURE DETERMINES FUNCTION
if the gene for coding an enz has a mutation then this affects formation of tertiary
structure
if enz deficient, then metabolic disorder occurs
enz catalyse formation of structural components like ligaments so can be harmful
ACTIVE SITE
enz r large mols
active site - indentation on surface of mol, shape complementary to subs
each enz highly specific as it can only catalyse reaction w specific subs
shape of active site can be altered by temp/ph
temp + ph alter bonds that hold tertiary structure
thus temp + ph can alter ability to catalyse
