-
what is a cofactor
chemical compound that binds to enzyme (inorganic)
-
what is a coenzyme
- "prothetic group":when bound tightly to enzyme
- organic compound
-
what is a holo enzyme
- "whole enzyme"
- apoenzyme + coenzyme
-
what are the factors that affect enzyme activity
- substrate
- enzyme
- pH
- temp
- cofactor
- inhibitors
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Forward reaction of creatinine kinase
- creatinine + ATP --> C-P + ADP
- ADP + p-phenolpyruvate --> PK--> ATP + Pyr
- Pyr + NADH --> LDH--> lactate NAD+
-
reverse reaction of creatinine kinase
- is faster than forward
- C-P + ADP --> CK --> C+ ATP
- ATP + Glu --> HK--> G6P + ADP
- G6P + NADPH --> G6PDH -->gluconate + NADPH+
-
what is the linear equation derived from michaelis equation
-
how is the first order graphically depicted in the michaelis menten curve
-
Creatinine kinase tissue source, sample requirement, separation
- refers to total CK, not specific
- tissue source: muscle
- sample: avoid hemolyzed samples. sample cannot be collected with EDTA, Citrate, Oxalate
- separation: electrophoresis separates fractions (MM,MB,BB)
-
CK-MB tissue source, diagnostic
- Tissue source: heart, skeletal muscle
- diagnostic: myocardial infarction (MI)
-
CK-MM tissue source, diagnostic
- tissue source: muscle
- diagnostic: skeletal muscle disorder, muscular dystrophy
-
CK-BB tissue source, diagnosis
- tissue source: brain
- diagnostic: CNS damage, tumors
-
LD function, sample requirement, tissue source
- f(x): catalyzes conversion of pyruvate and lactate
- tissue source: heart, liver, skeletal muscle, kidney, RBC
- sample requirement: serum preferred, no plasma with oxalate as anticoagulant. NO HEMOLYZED SAMPLES. Must be stored at 25C and analyzed w/in 48 hours
-
LD assay mechanism
- lactatee + NAD+ --> LD--> pyruvate +NADH + H+
- rate of reverse reaction is 3 times faster
-
LD 1 (HHHH)
LD 2 (HHHM)
tissue source and diagnostic
- tissue source: heart, RBC
- diagnostic: MI, anemia, hemolyzed specimen
-
LD 3 (HHMM)
tissue source, diagnostic
- tissue source: lung
- diagnostic: pulmonary disorder, acute pancreatitis, carcinoma
-
LD4 (HMMM)
LD5 (MMMM)
tissue, diagnostic
- tissue source: liver, skeletal muscle
- diagnostic: hepatic injury, skeletal muscle injury
-
-
abnormal LD pattern
- Suggestive AMI
- hemolytic anemia
-
AST sample collection
- stable at 4C and 20C
- avoid hemolysis
-
aspartate aminotransferase (AST)
f(x), tissue source, diagnosis
- f(x): transferase
- tissue source: liver
- diagnosis: hepatocellular disorders, skeletal muscle disorders
-
alanine aminotransferase (ALT)
f(x)
tissue source
diagnostic
- f(x): transferase
- tissue source: liver
- diagnostic: liver damage
-
ALT sample requirement
- heparinized, EDTA plasma acceptable
- slightly affected by hemolysis
-
alkaline phosphotase (ALP)
f(x)
tissue source
diagnostic
- f(x): hydrolase at an alkaline pH
- tissue source: liver, bone
- diagnostic: hepatobiliary, bone disorders
-
ALP sample requirement
- 4C for several hours
- slightly affected by hemolysis
-
ACP sample requirement
sample should be frozen or acidified to a pH < 6.5
-
Acid phosphatase (ACP)
f(x)
tissue source
diagnostic
- f(x): hydrolase in acid pH
- tissue source: liver, bone
- diagnostic: detection for prostatic carcinoma
-
γ-glutamyltransferase (GGT)
f(x)
tissue source:
diagnostic
- f(x) transferase
- tissue source: liver
- diagnostic: alcoholism
-
GGT sample requirements
stable with no loss of activity for 1 week
-
amylase
f(x)
tissue source
diagnostic significance
- f(x): hydrolase - breakdown of starch
- tissue source: pancreas
- diagnostic significance: AMS (atypical measles syndrome) 2-3 days, acute pancreatitis
-
amylase sample requirement
Rm temp for 1 week or 4C for 2 months
-
lipase
f(x)
tissue source
diagnostic significance
- f(x): hydrolase - fat breakdown
- tissue source: pancreas
- diagnostic significance: acute pancreatitis. More specific than AMS, last more than a week
-
lipase sample requirement
- rm stable for 1 week
- 4C for 3 weeks
- avoid hemolysis
-
enzymes requiring Mg2+ cofactor
- all CKs and fractions
- ALP
- ACP
-
enzymes requiring NAD+ cofactor
all LD and fractions
-
enzyme requireing pyridoxal 5' phosphate (P5P)
-
enzyme requiring gly-gly
GGT
-
enzyme requiring Ca2+, Cl-
amylase
-
enzyme that has no cofactors
lipase
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