BCH441 CH 16 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
DHFR
-dihydrofolate reductase converts dihydrofolate into tetrahydrofolate, a methyle group
shuttle required for de novo synthesis of purines, thymidylic acid, and certain AA
-tetrahydrofolate is the active form of folate in humans, inhibition of DHFR can cause
functional folate deficiency
-folate is needed by rapidly dividing cells to make thymine, so this effect may be
therapeutic
-ex: mathotrexate is used as cancer chemotherapy because it can prevent neoplastic
cells from dividing
-inhibit DHFR, prevent DNA synthesis, prevent cell replication
quote 1
-allostery and catalysis result from a common property of proteins: flexibility, which
gives rise to populations of conformers that interconvert on various timescalse. the
binding of an allosteric effector can result in the redistribution of protein conformational
ensembles and can alter the rates of their interconversion, therby modulating active site
or binding site geometries. both enzymes and noncatalytic proteins can be regulated by
allosteric means
quote 2
, -the emerging view of allosteric regulation in proteins examines the ability of an effector
to cause redistribution in the relative populations of protein conformations and the
mechanism by which this shift in populations can cause changes in catalytic or ligand
binding competence
quote 3
-proteins exist as complex statistical ensembles of conformers and that proteins unfold
and fold continuously in localized regions. these local unfolding events result in a alarge
number of conformations that may differ from each other only slightly, and this collection
of conformers is considered the native state ensemble. this view relies on the idea that
there are varying regions of stability in a given protein
molecular motors
-linear: kinesin and dynein, myosin, helicases
-rotating - flagella, atp synthase
-WATCH VIDEOS
structure of a striated muscle cell
-nerve impulses give an action potential that spreads over the sarcolemma membrane
and into the fiber along the t tubule network
-this induces ca release from the sr, ca then binds proteins within the muscle fiber and
induces contraction
actin
-thin filament +troponin and tropomyosin
-g actin (monomer)
-f actin (polymerized)
COMPLETE SOLUTIONS VERIFIED
DHFR
-dihydrofolate reductase converts dihydrofolate into tetrahydrofolate, a methyle group
shuttle required for de novo synthesis of purines, thymidylic acid, and certain AA
-tetrahydrofolate is the active form of folate in humans, inhibition of DHFR can cause
functional folate deficiency
-folate is needed by rapidly dividing cells to make thymine, so this effect may be
therapeutic
-ex: mathotrexate is used as cancer chemotherapy because it can prevent neoplastic
cells from dividing
-inhibit DHFR, prevent DNA synthesis, prevent cell replication
quote 1
-allostery and catalysis result from a common property of proteins: flexibility, which
gives rise to populations of conformers that interconvert on various timescalse. the
binding of an allosteric effector can result in the redistribution of protein conformational
ensembles and can alter the rates of their interconversion, therby modulating active site
or binding site geometries. both enzymes and noncatalytic proteins can be regulated by
allosteric means
quote 2
, -the emerging view of allosteric regulation in proteins examines the ability of an effector
to cause redistribution in the relative populations of protein conformations and the
mechanism by which this shift in populations can cause changes in catalytic or ligand
binding competence
quote 3
-proteins exist as complex statistical ensembles of conformers and that proteins unfold
and fold continuously in localized regions. these local unfolding events result in a alarge
number of conformations that may differ from each other only slightly, and this collection
of conformers is considered the native state ensemble. this view relies on the idea that
there are varying regions of stability in a given protein
molecular motors
-linear: kinesin and dynein, myosin, helicases
-rotating - flagella, atp synthase
-WATCH VIDEOS
structure of a striated muscle cell
-nerve impulses give an action potential that spreads over the sarcolemma membrane
and into the fiber along the t tubule network
-this induces ca release from the sr, ca then binds proteins within the muscle fiber and
induces contraction
actin
-thin filament +troponin and tropomyosin
-g actin (monomer)
-f actin (polymerized)
