ENZYMES Flashcards
They catalyze the transfer of amino groups and acids.
Transaminases
Transaminases catalyze the transfer of what?
amino groups and acids
This is an important reaction in the synthesis and degradation of amino acids.
Transaminases
Transaminases are an important reaction in what?
synthesis and degradation of amino acids.
This transfers an amino group between aspartate and keto acids
Aspartate transaminase (AST)
Aspartate transaminase (AST) transfers an amino group between what?
between aspartate and keto acids
What is the reaction for AST?
(aspartate + α-ketoglutarate AST→ oxaloacetate + glutamate)
This is the coenzyme in AST
Pyridoxal phosphate (vitamin B6)
AST exists in where?
CtRLSm
cardiac tissue, liver, skeletal muscle, and RBCs
Three major approaches are taken in the measurement of total activity.
True or false
TRUE
What are the three major approaches are taken in the measurement of total activity?
- The reaction with dinitrophenylhydrazine couples color reagent with keto acid product.
- The reaction with diazonium salts couples the salt with the keto acid product and forms a color.
- The coupled enzyme assay (Karmen method) involves NADH and malate dehydrogenase and keto acid to form NAD.
The reaction with dinitrophenylhydrazine couples color reagent with what?
with keto acid product.
The reaction with diazonium salts couples the salt with what?
with the keto acid product and forms a color.
The reaction with dinitrophenylhydrazine couples what?
couples color reagent
The reaction with diazonium salts couples the what?
Salt
What is the product of the reaction with dinitrophenylhydrazine?
keto acid product.
What is the product for a reaction with diazonium salts?
salt with the keto acid product and forms a color.
The clinical significance of AST elevations is that the elevations occur in what?
in patients with myocardial infarction, viral hepatitis, and skeletal muscle disease.
This is used to evaluate hepatocellular disorders
AST
AST is used to evaluate what disorder?
hepatocellular disorders
AST is up to 100 times upper reference limit in what disease?
viral hepatitis
Up to how many times is the upper reference limit for viral hepatitis?
up to 100 times upper reference limit in viral hepatitis
They are up to 20 times upper reference limit in what disease?
infectious mononucleosis
up to how many times is the upper reference limit in infectious mononucleosis?
20 times
They are up to 4 times upper reference
limit in what disease?
cirrhosis
up to how many times is the upper reference
limit in cirrhosis?
4 times
They are up to 8 times upper reference limit in what disease?
skeletal muscle disorders
up to how many times is the upper reference limit in skeletal muscle disorders?
8 times
up to how many times is the upper reference limit in pulmonary emboli?
3 times
They are up to 3 times upper reference limit in what disease?
pulmonary emboli (and acute pancreatitis??)
What is/are the source/s of error for AST?
Hemolysis
Aspartate transaminase is also known as …
SGOT
Serum Glutamic Oxaloacetic transaminase
catalyzes the transfer of an amino group from alanine to α-ketoglutarate with the formation of glutamate and pyruvate.
Alanine transaminase (ALT)
Alanine transaminase (ALT) catalyzes the transfer of what?
of an amino group from alanine to α-ketoglutarate
ALT is with the formation of what?
glutamate and pyruvate.
ALT is localized where?
SHLR
in the liver, with some in the heart, skeletal muscle, and RBCs.
The measurement of total activity of ALT is similar to the reactions of AST, except for what?
except that the coupled enzyme assay uses lactate dehydrogenase to reduce pyruvate to lactate and oxidize NADH.
Why is lactate dehydrogenase used in AST?
to reduce pyruvate to lactate and oxidize NADH.
In AST, this is used to reduce pyruvate to lactate and oxidize NADH.
lactate dehydrogenase
In ALT, this is used to reduce pyruvate to lactate and oxidize NADH.
lactate dehydrogenase
The clinical significance of ALT is in the what?
in the evaluation of hepatocellular disorders.
What are 2 examples of hepatocellular disorders?
hepatitis, cirrhosis
These are disorders that exhibit higher ALT levels than intra- or extrahepatic obstruction.
Hepatocellular disorders
Hepatocellular disorders (hepatitis, cirrhosis) exhibit lower ALT levels than intra- or extrahepatic obstruction.
True or False
False
higher ALT levels
ALT is more specific for liver disease than AST
True or False
TRUE
ALT, in conjunction with an decreased AST, is used to assess liver involvement with diagnosis of an AMI.
True or false
FALSE
increased AST
It is used to assess liver involvement with diagnosis of an AMI.
ALT in conjunction with an elevated AST
ALT, in conjunction with an elevated AST, is
used to assess what?
to assess liver involvement with diagnosis of an AMI.
ALT exhibits a significant increase in
muscular dystrophy
true or false
false
does not exhibit
It is not affected in cases of pulmonary emboli or acute pancreatitis.
ALT
AST is not affected in cases of pulmonary emboli or acute pancreatitis.
True or False
FALSE
ALT
ALT is not affected in cases of what?
in cases of pulmonary emboli or acute pancreatitis
ALT does not exhibit a significant increase in what?
muscular dystrophy
Source of error of ALT
Slight hemolysis does not interfere
ALP has high concentrations are found on what tissue locations?
PLiBKInS
in liver, bone, intestines, spleen, kidney, and placenta
ALP has the lowest concentrations are found in liver, bone, intestines, spleen, kidney, and placenta.
True or false
false
highest concentrations
ALP is found on cell surfaces, in sinusoidal and bile canalicular membranes in the what?
in the liver, and in bone osteoblasts.
This is found on cell surfaces, in sinusoidal and bile canalicular membranes in the liver, and in bone osteoblasts.
Alkaline phosphatase
ALP is found on what parts in the liver, and in bone osteoblasts?
on the cell surfaces, in sinusoidal and bile canalicular membranes
In normal adult serum, ALP is mainly of liver origin, with a small amount from bone.
True or False
TRUE
Increased serum ALP levels are seen in WHAT?
in hepatobiliary disease and bone disorders
Increased serum ALP levels are seen in hepatobiliary disease and bone disorders (with osteoblastic involvement)
True or false
TRUE
In hepatobiliary disorders, the increased levels are due to what?
due to obstructive disease
ALP levels are increased more significantly than ALT and AST.
True or false
True
In biliary tract obstruction, synthesis of ALP is induced by what?
induced by cholestasis
This causes serum ALP levels to rise 3 to 10 times the upper reference limit.
the synthesis of ALP is induced by cholestasis in biliary obstruction
In biliary tract obstruction, synthesis of ALP is induced by cholestasis, which causes serum ALP levels to rise up to how many times?
e 3 to 10 times the upper reference limit
The elevation of ALP is usually greater in cases of what?
in cases of extrahepatic obstruction
The elevation is usually greater in cases of intrahepatic obstruction in contrast to extrahepatic obstruction.
True or false
False
greater in cases extrahepatic obstruction than intrahepatic obstruction
hepatitis and cirrhosis are classified as hepatocellular conditions
True or false
true
In hepatocellular conditions, like hepatitis and cirrhosis, ALP rises up to how many times?
up to 3 times the upper reference limit.
Highest elevations of ALP are seen in what?
Paget disease
Paget disease is due to very high elevations of ALP
True or false
true
ALP levels increase with what?
with healing bone fractures.
Increased serum ALP levels are seen in hypophosphatasia
True or false
false
Decreased serum ALP
Decreased serum ALP levels are seen in what?
hypophosphatasia
Why are decreased serum ALP levels in hypophosphatasia?
because of lack of ALP bone isoenzyme
This disorder is characterized by insufficient bone calcification.
hypophosphatasia
hypophosphatasia is characterized by what?
characterized by insufficient bone calcification.
Source of error of ALP
Hemolysis
What are the 3 enzymes that have hemolysis as a source of error?
- ALP
- AST
- LIPASE
What is the tissue locations of amylase? SiSg Pa FO
Found in pancreas, salivary glands, small intestine, fallopian tubes, and other tissues
Increased serum levels in acute pancreatitis in amylase occur in how many hours after the onset of pain?
2-12 hours after the onset of pain
What is the peak value in increased serum levels in acute pancreatitis in amylase after the oonset of pain?
with peak
values in 24 hours
After the 24-hour peak value after the onset of pain in increased serum levels in acute pancreatitis in amylase, in how many days will it return to normal?
return to normal in 3-4 days.
Amylase is increased in what?
PPRC MIMA
- Mumps
- perforated peptic ulcer
- intestinal obstruction
- cholecystitis
- ruptured ectopic
- pregnancy
- mesenteric infarction
- acute appendicitis
What is the source of error in amylase?
- : In hyperlipidemia, triglycerides suppress AMS activity
- morphine and other opiates falsely elevate AMS levels
What is the tissue location of lipase? LIPAst
Found in pancreas, with lesser amounts in gastric mucosa, intestinal mucosa, adipose tissue.
Increased serum levels in lipase in acute pancreatitis occur in how many hours after the onset of pain?
occur in 4-8 hours after the onset of pain
After the 24-hour peak value after the onset of pain in increased serum levels in acute pancreatitis in lipase, in how many days will it return to normal?
return to normal in 8-14 days
What is the peak value in increased serum levels in acute pancreatitis in lipase after the onset of pain?
peak values in 24 hours
Lipase is increased in what?
D’PIC
- Perforated peptic ulcer
- duodenal ulcers
- intestinal obstruction
- cholecystitis.
Sources of error for lipase
Hemolysis because hemoglobin inhibits LPS activit
This inhibits lipase activity
Hemoglobin
Slight hemolysis interferes with ALT
true or false
false
does not interfere
Slight hemolysis interferes with ALT
true or false
false
does not interfere
What is the method used for ALT/SGPT??
Frankel Reitman
These are enzymes that catalyzes the intra-conversion of keto acids and amino acids
transaminase
The transaminase are enzymes that catalyzes the
intra-conversion of what?
keto acids and amino acids
dinitrophenylhydrazine is measured at how many nanometers?
490-550nm
What is the normal range for ALP?
0 – 30 U/L
What is the borderline range for ALP?
31 – 45 U/L
wHAT IS THE RANGE FOR POST CARDIAC INFARACTION in ALP?
45 – 100
What is the range for LIVER NECROSIS interpretation in ALT?
100 – 2000+
What is the interpretation if results range from 100 – 2000+ in ALT?
LIVER NECROSIS
What is the interpretation if the results range from 31 – 45 U/L in ALT?
borderline
What is the interpretation if the results range from 45 – 100 in ALT?
POST CARDIAC INFARCTION
What is the intrpretation if the result range from 0 – 30 U/L in ALT?
Normal
What is the method used for SGOT/AST?
Frankel Reitman
How many minutes and for how long must AST be incubated for?
30 mins at 37C
How many minutes and for how long must ALT be incubated for?
15 mins, 37C
What is the normal range for AST?
0 – 40 U/L
What is the range for BORDERLINE interpretation in AST?
41 – 50 U/L
What is the range for POST CARDIAC INFARCTION interpretation in AST?
50 – 400+
What is the range for LIVER NECROSIS interpretation in AST?
50 – 1000+
What is the interpretation if the results range from 0 – 40 U/L in AST?
normal
What is the interpretation if the results range from 41 – 50 U/L in AST?
BORDERLINE
What is the interpretation if the results range from 50 – 400+ U/L in AST?
POST CARDIAC INFARCTION
What is the interpretation if the results range from50 – 1000+ U/L in AST?
LIVER NECROSIS
What is the method used for AMYLASE?
Caraway, Modified
How long at at what temperature must amylase be incubated for?
5 mins, 37C
Invert to mix and read %T/absorbance at ????
against Water Blank.
610/640 nm
For Statfax: use Absorbance mode at 500nm against
water blank.
TRUE OR FALSE
FALSE
600 nm
For Statfax: use Absorbance mode at 500nm against
water blank.
TRUE OR FALSE
FALSE
600 nm
What is the normal range for amylase?
60-180 U/L
What method is used for LIPASE?
Tietz-Fiereck Turbidimetric Assay
Lipase buffer must be at pH of what?
pH 7.0
The decrease in turbidity at 550 nm is proportional to the lipase activity of the serum.
True or false
TRUE
The lipolytic action of lipase in the serum hydrolyze the olive oil emulsion to fatty acids, mono- and diglycerides and glycerol
true or false
true
What is the normal reference range for lipase?
30 – 200U/L by CLSI
Increased levels of lipase are associated with what diseases?
acute acute pic
- Acute peritonitis.
- acute pancreatitis
- perforated peptic ulcer
- , intestinal obstruction
- carcinoma of pancreas
It is generally agreed that lipase values have about the same significance as amylase values in the diagnosis of acute pancreatitis.
true or false
true
It is generally agreed that lipase values have about the same significance as amylase values in the diagnosis of what?
acute pancreatitis.
the serum lipase activity may rise more slowly than the serum amylase, but it may remain elevated for a longer time so that it may be more useful in the diagnosis and follow up of acute pancreatitis DURING WHAT?
During pancreatic disturbances,
During pancreatic disturbances, the serum lipase activity may rise faster than the serum amylase, but it may remain elevated for a longer time so that it may be more useful in the diagnosis and follow up of acute pancreatitis.
true or false
false
may rise more slowly
