Biochem lecture 7

competitive

type of inhibition in which inhibitor competes with substate for active site

EI

in competitive inhibition, the inhibitor forms a ____ complex

V0 = Vmax[S]/alphaKm + [S]

equation for Vo in competitve inhibition

un-competitive

type of inhibition which the inhibitor binds to spot other than the active site, rendering enzyme inactive

ESI

in un-competitive inhibition, the inhibitor forms the ____ complex

V₀ = V_max[S]/K_m + alpha’[S]

equation for V₀ in un-competitive inhibition

mixed

type of inhibition in which substrate can bind to spot OTHER than active site in E or ES complex

V₀ = V_max[S]/alphaK_m + alpha’[S]

equation for V₀ in mixed inhibition

increases; stays the same

in competitive inhibition, K_m ______ and V_max ____

decreases; decreases

in un-competitive inhibition, K_m ______ and V_max____

increases; decreases

in mixed inhibition, K_m ______ and V_max____

non-competitve inhibition

special case of mixed inhibition in which alpha = alpha’ and inhibitor can bind E or ES complex

stays the same; decreases

in non-competitive inhibition, K_m ______ and V_max____

irreversible inhibition

type of inhibition that involves suicide inhibitors that form covalent bonds with their target

permanently

suicide inhibitors ______ bind to the active site

penicillin

example of irreversible inhibition we talked about in class

regulatory enzyme

type of enzyme that is regulated so they can regulate something

feedback inhibition

when end product of a pathway is a molecule that shuts down the pathway

materials; energy

feedback inhibition prevents the waste of _____ and _____

allosteric modulation

binding of a molecule on one part of protein affects the shape, thus and behavior of the protein

active; regulatory

in allosteric modulation, there is an _____ site and a _______ site

speciic

both sites in allosteric modulation are _______

heterotropic enzymes

modulator is different from the substrate (binds outside active site)

homotropic enzymes

modulator IS the substrate (active site IS the regulatory site)

sigmoidal

change in rate caused by modulatorr in allosteric enzymes creates a _______ cuve

positive; negative

heterotrophic enzymes can either have ______ regulators or ____regulators

increase; not affect

you cannot predict the curve for heterotropic enzymes because positive regulators can either _____ K0.5 and _____ _____ Km and vice versa + same with negative regulators.

methylation

type of reversible covalent modification that adds a methyl group

ADP-ribosylation

type of reversible covalent modification that transfers an ADP-ribose group from NAD+ onto target molecules

acetylation

type of reversible covalaent modification that adds an acetyl group

adenylation

type of reversible covalent modification that adds an adenosine monophosphate (AMP)

Myristoylation

type of reversible covalent modification that adds carbon chains

ubiquitination

type of reversible covalent modification in which ubiquitin is added

ubiquitin

tags proteins for destruction (degraded by proteosome)

phosphorylation

type of reversible covalent modification that adds a phosphate group

protein kinase

enzyme that catalyzes the attachment of phosphoryl groups to specific amino acid residues

tyrosine, serine, threonine, sometimes histidine

kinase targets these amino acids:

structure; function

phosphorylation changes the _______ of protein, changing its _______

activate; inactivate

kinases either ___ or _____ proteins

Trypsin

protease that is activated by proteolytic cleaves and produced by pancreas and sent to your duodenum

gut

trypsin breaks down proteins in your ____

arginine; lysine

trypsin recognizes ____ and _____

trypsinogen

precursor (pre-cleavage) for trypsin

enteropeptidase

enzyme that clips off part of trypsinogen once it enter tthe duodenum, activating it to trypsin

trypsin inactivating protein

protein that binds to trypsin and keeps it inactive

tyrosine kinase

large family of plasma membrane receptors with intrinsic protein kinase activity, transduce extracellular signals by a mechanism fundamentally different from that of GPCRs

glycogen phosphorylase

enzyme that takes one glucose monomer off at a time through phosphorylation by putting phosphate group onto glucose and cleaving if off

insulin

hormone that we release when we want to decrease glucose in blood by stimulating the inactivation of GPK

glucagon

hormone that stimulates GPK pathway

serine

amino acid on GPK that can be reversible phosphorylated

a

more active form of glycogen phosphorylase ___

b

less active form of glycogen phosphorylase ___

disordered, ternary complex

name of complex:

ordered, ternary complex

name of complex:

glucose; ATP

hexokinase binds ___ and _____

no ternary complex

image shows an enzyme with _____

increases; lower

in competitive inhibition Km ______ by factor alpha, making it appear that the enzyme has a _____ affinity for substrate.

stays the same; “wash out” the effects of the inhibitor

in competitive inhibition, the Vmax ______ because as your keep increase [S], you ____________.

decreases; higher

in un-competitive inhibition Km ______ , making it appear that the enzyme has a _____ affinity for substrate.

protein kinase

enzyme that catalyzes the attachment of phosphoryl groups to specific amino acid residues

ATP

𝛾-phosphoryl group derived from ____ is transferred to Ser, The, Tyr (occasionally His) by PROTEIN KINASE

protein phosphatase

enzyme that catalyzes the removal of phosphoryl groups

kinase

Glycogen Phosphorylase is not a ____ because it does not utilize ATP

Phosphorylase Phosphatase

 removes phosphoryl groups from glycogen phosphorylase

A; B

phosphorylase phosphatase converts ___ form to ___ form of glycogen phosphorylase

B; A

phosphorylase kinase converts ___ form to ___ form of glycogen phosphorylase

e) All of the above regulate ATCase.

The allosteric enzyme ATCase is not regulated by a:

a) positive regulator.

b) negative regulator.

c) heterotropic regulator.

d) homotropic regulator.

e) All of the above regulate ATCase.

d) contains a catalytic triad.

Chymotrypsin:

a) is a zymogen.

b) is activated through phosphorylation.

c) cuts at the carboxy-end of positively charged amino acid residues within polypeptides.

d) contains a catalytic triad.

e) is an enzyme with no disulfide bonds.

d) Siliconation

Which of the following is not a common form of regulation through covalent modification?

a) Adenylation

b) Ubiquitination

c) Myristoylation

d) Siliconation

e) Acetylation

d) Two of these are true.

Blood coagulation involves:

a) a kinase cascade.

b) zymogen activation.

c) serine proteases.

d) Two of these are true.

e) All of these are true.

 b) Phosphorylase activates phosphorylase kinase.

Which of the following is false about glucose metabolism in muscle cells:

 a) Glucose release requires active phosphorylase kinase.

 b) Phosphorylase activates phosphorylase kinase.

c) Insulin stimulates the inactivation of phosphorylase kinase.

 d) Phosphorylase kinase must put a phosphate group on a serine, threonine, or tyrosine of its target protein.

 e) Insulin has the opposite effect of glucagon.