BCH441 CH 15 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
factors that influence enzymatic activity
-basics: rate slows as product accumulates, rate depends on substrate availability
-genetic controls - protein expression
-protein degradation (1/2 life_
-enzymes can be modified covalently
-zymogens (synthesized in inactive form)
-isozymes (composition/quaternary structure)
-modulator proteins
-allosteric effectors
covalent modification
-called interconvertible enzymes
-ex: protein kinase and protein phosphatase are called converter enzymes
-protein kinase converts atp to adp to add phosphate group
-protein phsphatase removes phosphate group
zymogen activation
-ex: insulin
-proinsulin is an 86 residue precursor to insulin-proteolytic removal of residues 31 to 65
yields insulin
, -residues 1-30 remain linked to 66 thru 87 by a pair of interchain disulfide bridges
-ex: chymotripsinogen cleaved into chymotrypsin
enzyme cascade of blood clotting
-intrinsic and extrinsic pathways
-converge at factor X
-lead to crosslinked fibrin clot
-basically a bunch of zymogen activation steps
isozymes of lactate dehydrogenase
-LDH
-if active muscle becomes anaerobic, it produces pyruvate from glucose via glycolysis
-needs ldh to regenerate NAD+ from NADH so glyclysis can continue
-lactate produced is release into blood, muscle ldh isozyme (A4) works best in NAD+
regenerating direction
-heart tissue is aerobic and uses lactate as fuel, converting it to pyruvate via ldh and
using the pyruvate to fuel the citric acid cycle to obtqain energy
-heart ldh isozyme B4 is inhibited by excess pyruvate so that fuel wont be wasted
-you can measure the amount of H4 ldh in the blood to determine if someone has had a
heart attack
modulator proteins
-PKA (cyclic amp dependent protein kinase_
-50 to 170 kD R2C2 tetramer
-two R (regulatory) subunits bind cAMP
-cAMP bindin greleases the r subunits from the c (catalytic_ subunits
COMPLETE SOLUTIONS VERIFIED
factors that influence enzymatic activity
-basics: rate slows as product accumulates, rate depends on substrate availability
-genetic controls - protein expression
-protein degradation (1/2 life_
-enzymes can be modified covalently
-zymogens (synthesized in inactive form)
-isozymes (composition/quaternary structure)
-modulator proteins
-allosteric effectors
covalent modification
-called interconvertible enzymes
-ex: protein kinase and protein phosphatase are called converter enzymes
-protein kinase converts atp to adp to add phosphate group
-protein phsphatase removes phosphate group
zymogen activation
-ex: insulin
-proinsulin is an 86 residue precursor to insulin-proteolytic removal of residues 31 to 65
yields insulin
, -residues 1-30 remain linked to 66 thru 87 by a pair of interchain disulfide bridges
-ex: chymotripsinogen cleaved into chymotrypsin
enzyme cascade of blood clotting
-intrinsic and extrinsic pathways
-converge at factor X
-lead to crosslinked fibrin clot
-basically a bunch of zymogen activation steps
isozymes of lactate dehydrogenase
-LDH
-if active muscle becomes anaerobic, it produces pyruvate from glucose via glycolysis
-needs ldh to regenerate NAD+ from NADH so glyclysis can continue
-lactate produced is release into blood, muscle ldh isozyme (A4) works best in NAD+
regenerating direction
-heart tissue is aerobic and uses lactate as fuel, converting it to pyruvate via ldh and
using the pyruvate to fuel the citric acid cycle to obtqain energy
-heart ldh isozyme B4 is inhibited by excess pyruvate so that fuel wont be wasted
-you can measure the amount of H4 ldh in the blood to determine if someone has had a
heart attack
modulator proteins
-PKA (cyclic amp dependent protein kinase_
-50 to 170 kD R2C2 tetramer
-two R (regulatory) subunits bind cAMP
-cAMP bindin greleases the r subunits from the c (catalytic_ subunits
