PRELIM LABORATORY L1: ENZYMES Flashcards
optimal pH for ALP
9.0-10.0
activator of ALP
magnesium
major tissue sources of ALP (from point of origin)
intestinal-placental-bone-liver
heat denaturation order of ALP isoenzymes (heat stable to heat labile)
Regan-Nagao-placental-intestinal-liver-bone
what ALP isoenzymes can be detected if added with phenylalanine inhibitor
liver, bone
what ALP isoenzymes can be detected if added with levamisole inhibitor
placental, intestinal
what ALP isoenzymes does phenylalanine inhibit?
placental, intestinal
what ALP isoenzymes does levamisole inhibit?
liver, bone
carcinoplacental ALPs
Regan, Nagao
highest elevation seen of ALP
Paget’s Disease/Osteitis Deformans
Clinical significance of ALP
evaluation of hepatobiliary and bone disorders
a continuous-monitoring technique that allows calculation of ALP activity based on the molar absorptivity of p-nitrophenol
Bowers and McComb
color of p-nitrophenol
yellow
color of p-nitrophenylphosphate
colorless
source of error for ALP
hemolysis
delay in running sample
following ingestion of high-fat meal
how many time more concentrated is ALP in RBC than serum?
6 times
optimal pH of ACP
5.0
major tissue source of ACP
prostate
clinical significance of ACP
elevated in prostatic carcinoma
more specific marker for prostatic carcinoma
prostate specific antigen (PSA)
how many days does ACP activity in seminal fluid from vaginal washing
4 days
major isoenzymes of ACP
prostatic, erythrocytic, bone
specific ACP
prostatic
non-specific ACP
erythrocytic
tartrate-resistant ACP
bone
inhibitor of prostatic ACP
tartrate
inhibitor of erythrocytic ACP
formaldehyde and cupric sulfate
specific substrate of prostatic ACP; for quantitative endpoint reactions
thymolphthalein monophosphate
most commonly used substrate for ACP, also for continuous monitoring methods
naphthyl phosphate
assay for ACP
Immunoenzymatic Assay (Tandem E)
if ACP sample is not assayed, what should be done? If done, how many days stable
frozen or acidified at <6.5 pH; stable for 2 days
T or F:
is hemolyzed sample accepted for ACP testing? Why?
F; ACP is present in RBCs
major tissue sources of AMY
acinar cells of the pancreas, salivary glands
activators of AMY
calcium, chloride, iodine, bromide
earliest pancreatic marker
AMY
first pancreatic marker to back to normal levels
AMY
smallest enzyme
AMY
samples for AMY
serum, urine, saliva
isoenzymes of AMY (from point of origin)
P-type isoamylase (amylopsin)->S-type isoamylase (pytalin)
(AMY) measures the disappearance of starch substrate, based on the disappearance of color
Amyloclastic
dye used in amyloclastic method
iodine
color of starch+iodine in amyloclastic method
bluish black
principle of amyloclastic method
decrease in color is directly proportional to AMY concentration
T or F:
iodine is an insoluble dye that cannot be bound to starch
F
(AMY) measures the appearance of the product
saccharogenic
principle of saccharogenic method
concentration of reducing sugar is directly proportional to AMY activity
(AMY) measures the increasing color from the production of product couples with a chromogenic dye
chromogenic
principle of chromogenic method
increase in color intensity is proportional to AMY activity
T or F:
chromogenic dye is soluble and can bind to starch
F
(AMY) coupling of several enzyme systems to monitor amylase activity
continuous monitoring (change of absorbance at 340 nm, 6.9 pH)
little loss of AMY activity occurs at what duration and temperature
room temperature for 1 week or 4 C for 2 months
drugs that can cause false elevation of AMY
morphine and other opiates
principle of LPS
hydrolyzes the ester linkages of fats to produce alcohol and fatty acids
most specific enzyme
LPS
late marker for pancreatitis
LPS
how many days does LPS persist
5 days
how many days does AMY persist
2-3 days
how many isoenzymes does LPS has and which is the most specific and sensitive?
3; L2
assay used for LPS
Cherry Crandal
substrate for Cherry Crandal
olive oil
incubation time in Cherry Crandal
24 hours
(LPS) more pure form of TAG
triolein
end color of Cherry Crandal method
pink
more rapid assay method of LPS
turbidimetry
assays for LPS
Cherry Crandal
Turbidimetric methods
Colorimetric methods (coupled enzymatic reaction)
little loss of LPS activity occurs at what duration and temperature
RT for 1 week or for 3 weeks at 4 C
hemolyzed sample in LPS can cause what kind of result
false-negative (Hgb inhibit activity of LPS)
principle of creatine kinase
catalyzes the transfer of phosphate to creatine
3 major isoenzymes of CK
CK-MM
CK-MB
CK-BB
highest elevation of CK is seen in what condition
Duchenne’s Muscular Dystrophy
Macro-CK is comprised of:
CK-BB complexed with immunoglobulin (IgG/IgA)
what is mitochondrial CK
bound to exterior surface of the inner mitochondrial membranes of muscle, brain, and liver
arrange all CK isoenzymes
cathodal to anodal
Mi-MM-Macro-CK-MB-BB
methods for measurement of CK
electrophoresis
ion-exchange chromatography
several immunoassays
immunoassays that can detect CK-MB
radioimmunoassay (RIA)
immunoinhibition methods
forward/direct assay enzyme activity of CK
Tanzer-Gilvarg
pH of CK forward assay
9.0
enzymes activated in Tanzer-Gilvarg
CK
pyruvate kinase
LDH
reverse/indirect assay enzyme activity of CK
Oliver-Rosalki/Rosalki and Hess
pH of CK reverse assay
6.8
how many times much faster is Oliver-Rosalki than Tanzer-Gilvarg method
2-3 times
enzymes activated in Oliver-Rosalki
CK
hexokinase
G6PD
what causes elevation of CK in hemolyzed samples
Adenylate kinase (will react to ADP to produce ATP)
sample consideration for CK
serum should be stored in dark place (will be inactivated by light)
T or F:
CK inactivation by light is reversible
T
storage consideration of CK sample if not analyzed asap
storage in dark at 4C for 7 days or at 20C for 1 month when the assay is conducted using a sulfhydryl activator
ref range of CK
Male: 15-160 U/L
Female: 15- 130 U/L
ref range of CK-MB
<6% of total CK
least specific enzyme
lactate dehydrogenase
principle of LDH
catalyzes the interconversion of lactic and pyruvic acids
major isoenzymes of LDH
cathodal->anodal
LD5-LD4-LD3-LD2-LD1
Most abundant LDH isoenzyme
LD2
highest elevation of LDH is seen in what condition
pernicious/megaloblastic anemia
what condition is LD-flipped pattern seen aside from AMI
hemolytic anemia
what is LD6
alcohol dehydrogenase, present in arteriosclerotic cardiovascular failure
forward/direct assay of LDH
Wacker
pH of LDH forward assay
8.8 (8.3-8.9)
reverse/indirect assay of LDH
Wrobleuski LaDue
pH of LDH reverse assay
7.2 (7.1-7.4)
how many times faster is Wrobleuski than Wacker
3X
storage for LDH if not analyzed asap
stored at 25C and analyzed within 48 hours
ref range of LDH
100-225 U/L
other name of aspartate aminotransferase
serum glutamic oxaloacetic transaminase
major tissue sources of AST
cardiac muscle>liver>skeletal muscle>kidney>pancreas>RBCs
2 isoenzymes of AST
cytoplasmic
mitochondrial
AST isoenzyme that is increased in conditions producing cellular necrosis
mitochondrial AST
when is AST activity stable in serum
3-4 days at ref temp
ref range of AST
5-30 U/L
assay of AST
Karmen method
pH of Karmen
7.3-7.8
enzymes activated in AST assay
AST
malate dehydrogenase
other name of alanine aminotransferase
serum glutamic pyruvic transaminase
major source of ALT
liver
most liver specific enzyme
ALT
what is DeRitis ratio
to determine if the cause of liver disease is hepatocellular or hepatobiliary
DeRitis ratio of acute hepatits
> 1.0
assay of ALT
couple enzymatic reaction
pH of ALT assay
7.3-7.8
enzymes activated in ALT assay
ALT
LDH
what enzymes are not affected by hemolysis
ALT
ALT is stable for how many days
3-4 days at 4C
ref range of ALT
6-37 U/L
7th LDH isoenzyme
LDX
<1 De Ritis ratio
non-alcoholic steatohepatitis (NASH)
> 1/>2 De Ritis ratio
alcoholic liver disease
principle of Karmen method
catalyzes the reduction of oxaloacetate to malate with oxidation of NADH
