problem set 9 Flashcards
anticoagulant
- aspirin
- large doses of vitamin E
- Coumadin
what is the anticoagulant found in small quantities in the blood
heparin
what is the formation of a clot within a blood vessel
thrombsis
what is it called if the clot breaks loose and moves elsewhere
embolism
Prothrombin, fibrinogen, and pepsinogen are examples of
zymogen
proenzyme
it is an anti-coagulant because it complexes Ca2+, which is needed for blood clotting
oxalate
citrate
what is the inactive enzyme that is the precursor to the peptidase found in the stomach
pepsinogen
any metal that is required for enzyme activity is called
cofactor
specific area on the enzyme where the chemical reaction takes place
catalytic site
specific area on the enzyme where the substrate binds
contact site
what is the cofactors plus the protein part called
holoenzyme
what is the cofactor that is organic but not a protein called
coenzyme
what peptidase has an optimum pH range near 2
pepsin
what peptidase is found in the small intestine
trypsin
what is the inactive protein part (without cofactors) of an enzyme called
Apoenzyme
what is the largest protein found in blood plasma, its function is blood coagulation
fibrinogen
different forms of an enzyme that catalyze the same reaction in different organs and tissues of the body is called
isoenzyme
what vitamin is needed for the synthesis of collagen
vitamin C
if a blood test taken in the emergency room indicates a high level of LDH and CK enzymes, what could be the cause
heart attack
Thiamine: coenzyme
TPP
Riboflavin: coenzyme
FAD
Niacin: coenzyme
NAD
Folic Acid: coenzyme
THF
Pantothenic acid:coenzyme
Coenzyme
TRUE about general zymogens
- they usually have their catalytic site blocked by several amino acids
- several blood clotting enzymes are synthesized as zymogens
FALSE about general zymogens
- catalytic activity
- usually smaller than active enzyme
- important for the enzymes needed for carbohydrate metabolism
- they are sometimes called apoenzymes
TRUE plasma proteins
- they are mainly made in the liver
2. serum albumins help maintain osmotic pressure
FALSE plasma proteins
- in times of protein deprivation they will be metabolized before muscle protein
- there are only four plasma proteins
enzymes are held together by…
- hydrogen bonds
2. salt bridges
what happens to the rate of an enzyme catalyzed reaction as substrate concentration is raised beyond the saturation point
(enzyme concentration remains constant)
remains the same
NOT peptidases
a. pepsin
b. plasmin
c. amylase
d. trypsin
e. thrombin
c. amylase
e. thrombin
TRUE concerning trypsinogen and trypsin
a. trypsin is a protein while trypsinogen is not
b. trypsin is larger protein than trypsinogen
c. trypsin has catalytic ability while trypsinogen does not
d. both have catalytic ability but not for the same substrate
c. trypsin has catalytic ability while trypsinogen does not
if an enzyme’s turn over rate is very high, it is
very efficient
which is found in blood plasma but not in blood serum
fibrinogen
calcium ions are needed for __ to be converted into ___
prothrombin –> thrombin
what compound causes the conversion of fibrinogen to fibrin
thrombin
what is the actual blood clot
fibrin
what destroys the blood clot after it is no longer needed
plasmin
what is the inactive precursor of thrombin
prothrombin
what two things are necessary for the precursor (prothrombin) to be converted to thrombin
- calcium ions
2. thromboplastin
enzyme (given to patient after a heart attack) which is used to convert plasminogen to plasmin
streptokinase
where would you find covalent bonding
- disulfide bonds
- irreversible inhibition
- peptide bond
- amide bond
why can enzymes be used in diagnostic medicine
- normally, blood plasma contains very small amounts of enzymes
- the same enzyme might have slight structural differences depending upon what type of tissue it is in
- tissue damage can cause enzymes to leak into the blood
- computerized assay procedures can measure very small quantities of enzymes
TRUE concerning enzymes vs. hormones
- all enzymes are proteins, while some hormones are proteins
- low concentrations of either can have a dramatic effect
- hormones can be made in a gland and travel through the blood stream
- enzymes are used in the cells where they are made
factors affecting the activity of all enzymes
- pH
- temperature
- substrate saturation
- genetic control to increase the concentration of the enzyme
catalytically active
holoenzyme
TRUE pepsin and pepsinogen
pepsin has catalytic ability while pepsinogen does not
part of the enzyme most likely to be deactivated by temperature
apoenzyme
what compounds react with hyrolase enzymes in the body
- fat
- polysaccharides
- corn oils
- tetrapeptide
- ethyl acetate
true of noncompetitive inhibitors
a. Mercury poisoning is an example
b. inhibitor has a different binding site than the substrate
c. binding the inhibitor alters the 3-D shape of the enzyme
d. allosteric enzymes inhibitors are examples
lactose
substrate
maltase
enzyme
maleate isomerase
enzyme
alanine
substrate
urease
enzyme
tyrosine synthetase
enzyme
glutamic acid
substrate
Allosteric enzymes TRUE
a. they are affected by regulator molecules, which can be inhibitors or activators
b. usually 2 or more subunits, with one unit having the active site, and the other having a regulatory site
c. can be reversed by adding more substrate
d. some allosteric enzymes have several different sites for different regulator molecules
false allosteric enzymes
- allosteric enzymes can cause build up of metabolic products
true competitive inhibitors
a. inhibitors resembles the substrate
b. can be reversed by adding more substrate
c. an example is ethanol as an antidote for methanol poisoning
d. sulfa drugs are an example
false competitive inhibitors
- binds at different site than the substrate
2. allosteric enzyme inhibitors are an example
what type of enzyme would be synthezied first as a zymogen
- protein digesting enzymes
2. blood clotting enzymes
what causes permanent enzyme denaturing
a. very high temperatures
b. large pH changes
TRUE acetylcholine
- contains ester linkage
- deficiency in the brain is involved in Alzheimer
- it is a neurotransmitter
- a molecule that blocks its receptor site can be used as a muscle relaxant
TRUE nerve gas
- it forms a permanent covalent bond with an amino acid at the active site
- it can cause convulsions and death
- it affects the enzyme acetylcholine esterase
can be reversed by adding an excess of the substrate
competitive
which usually forms covalent bonds with the enzyme
irreversible
inhibitors look like the substrate
competitive
lead poisoning destroys the salt bridges of many enzymes, but it can be removed with EDTA
–lead poisoning is what kind of inhibitor
non-competitive
inhibitor binds to enzyme at different site than substrate, but it can be removed
non-competitive
nerve gas permanently binds to serine in the active sites
irreversible
antifreeze (ethylene glycol) is oxidized in the liver to oxalic acid, which is toxic. The treatment of antifreeze poisoning is intravenous solution of ethanol. what kind of inhibitor is ethanol to the liver enzyme
competitive
olive oil to glycerol & 3 fatty acids
hydrolases
cis 2-pentene to trans 2-pentene
isomerases
glucose-6-phosphate & ADP to glucose & ATP
transferases
isocitrate dehydrogenase
oxidoreductases
petidases
hydrolases
phosphoglucomutase
isomerases
glucose-6-phosphate to fructose-6-phosphate
isomerases
oxaloacetate & acetyl-CoA to citric acid
ligases
transfers an amino group from aspartic acid
transferases
hydrolyzes sucrose
hydrolases
removes CO2 from pyruvic acid
lyases
citric acid sythetase
ligases
oxidizes succinic acid
oxidoreductases
phosphoglycerate kinase
transferases
glutamic-pyruvic transaminase
transferases
lactose to glucose and galactose
hydrolases
pyruvate decarboxylase
lyases
amylose to glucose
hydrolases
removes 2H from an alcohol
oxidoreductases
