Glossary of Enzymology

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example of plasma specific enzymes?
blood coag enzymes
examples of secretion enzymes?
amylase, lipase, acid/alkaline phosphatase
examples of metabolism enzymes?
2 tumor markers?
when are extracellular enzymes of interest?
Where are they synthesized?
when decreased.
At the liver.
What're the 2 types of extracellular enzymes?
When are secreted enzymes increased?
1. Excretion is blocked (up)
2. Overproduced (up)
3. Tissue damaged (low)
When are metabolic enzymes increased?
When are tumor markers increased?
When cell damage happens.

During tumor cell growth.
What reaction type does LD do?
What can interfere?
-Gross hemolysis - SIGNIFICANT elevation in serum
-Instability - should keep below 25'C.
Where is each LD type found?
1 - heart/RBCs
2 - Renal
3 - lung/spleen/pancreas
4 - liver/skeletal muscle
5 - liver/skeletal muscle
When would LD1 be elevated?
-in heart MI - 1,2 flip
-in hemolytic anemia, megaloblst
When would LD3 be elevated?
-In Pulmonary disorders
-In malignancies
When would L4/5 be elevated?
In liver disease
From highest-low, what is the order of LD amounts?
2, 1, 3, 4, 5
What are possible ways for direct msmnt of LD? What's better?
-immunoinhibition - better
What are sensitivity/spcfty of LD-1? When?
What disadvantage does this create?
-about 90%
-within 24 hours - takes a long time to diagnose.
-may not diagnose slight infarcts.
What type of reaction does CK catalyse?
How is CK directly measured?
-Electrophoresis (but bad)
-Reaction inhibition
Explain reaction inhibition for LD-1 - sorry forgot earlier.
Ab to M subunit - precipitate all but LD1
Now explain reaction inhibition for CK.
Automated; Ab to B subunit, enzymatic 2ndary Ab to M peptide.
Does hemolysis affect CK assays?
What else interferes?
Yes; not because RBCs have CK, but AK, and it participates, falsely elevating CK.
Daylight decreases CK activity.
When is CKMB elevated?
in myocardial infarct.
When is CKMM elevated?
in muscle injury, iection, exercise.
When is CKBB elevated?
in brain damage and tumors
What is the sensitivity/spcfty of CK-MB, and when?
about 90%, within 7-18 hrs; peak at 24 hrs.
How is CK gotten rid of?
Small, kidney filters; disappears quickly - 2,3 days.
What affects sensitivity/spcfty?
High CK, low sens.
Low CK, poor specif.
What/Where is AST significant?
What are its two isoforms?
What type of reaction?
Aspartate aminotransfrase.
Heart and mostly in Liver.
What can interfere with AST levels?
What are AST and ALT used to assess?
Their ratio is for liver damage.
What/Where is ALT significant?
What type of reaction?
what interferes with reaction?
alanine aminotransferase, LIVER.
How is the AST/ALT ratio altered in liver damage?
-ALT is higher, so the ratio is lower, usually.
-When AST is HIGHER than ALT, this indicates poooor prognosis.
If AST and ALT are decreasing in liver disease, what do you think?
Slow decrease is recovery.
Fast decrease is failure to produce them b/c of liver necrosis.
What type of rxtn is ALP?
Special conditions?
Where is it found? (isoenzymes)
Hydrolase; pH = 9-10, need Mg2+
Liver ALP1
Bone ALP2
Placenta/intestine ALP3
What diseases can ALP2 be associated with if increased?
Healing fractures,
Pregnancy and Puberty.
What diseases is ALP1 associated with?
Biliary tract obstruction
What interferes with ALP levels?
Hemolysis = RBCs have 6x the ALP as in plasma
What type of reaction does 5 nucleotidase do?
What does it help to diagnose?
Hepatobiliary disorders - liver.
What does GGT very sensitively indicate?
What type of rxtn does it do?
Where is it significant?
Liver, brain, kidney, pancreas.
What is the use of GGT?
Helps differentiate bone from liver disorders with ALP
What reaction type is Amylase?
Where is it found?
What is it mainly used for?
Pancreas, salivary glands.
Diagnosing pancreatitis.
What specimens are used for amylase analysis?
Serum + urine -> elevated levels will cause filtering by glomerulus, is a small molecule.
What type of reaction is Lipase?
Where is it found?
What is its main use?
Pancreas, some stomach/WBCs/fat.
Diagnosing pancreatitis, elevated longer than amylase.
How can the water-soluble lipase act on water-insoluble lipids?
Cofactors serve as detergents.
What specimens are used for lipase analysis?
What error to look out for with lipase?
Only serum; lipase is filtered but reabsorbed.
-Hemolysis will inhibit lipase activity.
What reaction type is Acid phosphatase?
Where is it found?
What error affects it?
-Prostate, bone, liver, spleen, kidney, RBCs.
-Hemolysis falsely elevates levels.
-Instability in >R.Temps
What are 2 uses of the acid phosphatase enzyme assay?
-Detect metastisized prostate cancer in bone; (PSA is better).
-Forensic; from seminal fluid in rapes, 4 days later.
What type of reaction is aldolase?
Where is it found?
What error affects it?
-Skeletal muscle, liver, kidney, brain.
What was the Aldolase assay mainly used for?
Pancreas disorders, but not much anymore.
-What type of reaction is done w/ Cholinesterase?
-Where is it found?
-Hydrolase reaction.
-In liver, pancreas, heart, serum.
What are 2 uses for cholinesterase?
1. Measure poisoning extent due to insecticides
2. Measure poisoning extent due to anesthesia.
What error affects cholinesterase assays?
Hemolysis - RBCs contain AChE, which this enzyme is a surrogate for.

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