Class 1 Enzymes Flashcards
LD (lactate Dehydrogenase) is a metalloenzyme because it contains
Zinc
What is the coenzyme of LD?
NAD
Forward reaction of LD has a optimal pH of?
8.8-9.8
Backward reaction of LD has an optimal pH of?
7.4-7.8
Lactate + NAD ——LD—-> Pyruvate + NADH + H is what type of reaction?
Forward reaction
Pyruvate + NADH + H ——LD—-> Lactate + NAD is what type of reaction?
Backward or Reverse reaction
Very high activities of LD is seen in what organ?
Heart
RBCs
Kidney
Liver
Skeletal muscles
Lesser amounts of LD is seen in what organs
Lungs
Smooth muscles
Brain
LD1 and LD2 are found in what tissue organs?
Heart
RBCs
Kidney
If LD1/LD2 is increased, what are the suspected disorders?
Myocardial Infarction
Hemolyzed specimen
Megaloblastic anemia
Hemolytic anemia
Acute renal infarction
In serum, what LD isoenzyme is seen in high amounts
LD2
What LD isoenzymes are considered heat stable?
LD1, LD2, & LD3
Most negatively charged isoenzyme?
LD1
LD3 is found in which organs?
Lungs (major)
Lymphocytes
Spleen
Pancreas
This type of isoenzyme is increased or elevated in any type of cancer
LD3
Among all types of isoenzymes which is considered the least specific?
LD3
If the patient has pneumonia, what isoenzyme is suspected to be elevated?
LD3
The patient has lympocytosis, what isoenzyme is elevated?
LD3
Which isoenzyme is considered to be heat and cold labile?
LD4 & LD5
Injury of the liver or skeletal muscle will cause elevation of?
LD4 & LD5
This isoenzyme os found in human testis and sperm
LDX (XXXX)/(CCCC)
Isoenzyme LD6 is also known as
Arterosclerotic cardiovascular failure
Alcohol dehydrogenasse
True or False
Non-hemolyzed sample needed in testing LD
True
—> kasi RBCs have LD, so hemolyzed samples will cause false elevation.
LDH is inhibited by?
Sulfhydryl reagents
EDTA
Excess pyruvate and lactate
Borate and oxalate
This method measure the forward reaction of LD
Wacker Method
This method measure the backward reaction of LD
Wroblewski-Ladue method
True or False
LD2 is normally higher than LD1
True
Reference range of LD
Pyruvate to Lactate = 80-280 U/L at 37C
Lactate to Pyruvate = 100-225 U/L at 37C
How long does it take for total LD to rise after onset of chest pain?
12-24 hours
How long does it take for the total LD to reach its peak?
48-72 hours
Total LD remains elevated for how long after onset of chest pain?
10 days
Myocardial infarction is suspected when there is flipped in LD pattern (LD1>LD2) followed by the presence of?
CK2
—> pag walang CK2 most probably and caused ng flipped LD pattern ay hemolysis or renal infarction
This is needed by the red blood cells to maintain integrity of the cell membrane structure
NADPH
This is needed as starting material for nucleotide and nucleic acid synthesis
Pentose Phosphate
This catalyzes the oxidation of glucose 6- phosphate to 6-phosphogluconate or the corresponding lactone
G6PD
An inherited sex-linked trait that develops hemolysis only when oxidative stress occurs, as with infections and after ingestion of certain drugs or fava bean
G6PD Deficiency
G6PD is found in?
Erythrocytes
Adrenal cortex
Spleen
Lymph nodes
Lactating mammary gland
This acts as a copper transport protein
Ceruloplasmin
This catalyzes the oxidation of ferrous iron (Fe2+) to Ferric iron (Fe3+)
Ceruplasmin
This disease is characterized by accumulation of copper in several organs such as the eyes leading to Kayse-Fleischer Ring
Wilson’s disease
Decreased ceruloplasmin is seen in?
1.) Renal disease associated with protein loss and severe nutritional CHON deficiencies
2.) Wilson’s disease
Glycoprotein that binds copper in the plasma
Ceruloplasmin
Specimen requirements for testing G6PD
Red cell hemolysate - assay for deficiency of the enzyme
Serum - evaluation of enzyme elevations
