Enzyme

  1. what is a cofactor
    chemical compound that binds to enzyme (inorganic)
  2. what is a coenzyme
    • "prothetic group":when bound tightly to enzyme
    • organic compound
  3. what is a holo enzyme
    • "whole enzyme"
    • apoenzyme + coenzyme
  4. what are the factors that affect enzyme activity
    • substrate
    • enzyme
    • pH
    • temp
    • cofactor
    • inhibitors
  5. Forward reaction of creatinine kinase
    • creatinine + ATP --> C-P + ADP
    • ADP + p-phenolpyruvate --> PK--> ATP + Pyr
    • Pyr + NADH --> LDH--> lactate NAD+
  6. 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+
  7. what is the linear equation derived from michaelis equation
    chart?chf=bg,s,00000000&cht=tx&chl=%5Cfrac%7B1%7D%7Bv%7D%20%3D%20%5Cfrac%7Bkm%7D%7BVmax%5BS%5D%7D%20%2B%20%5Cfrac%7B1%7D%7BVmax%7D&chs=316x76
  8. how is the first order graphically depicted in the michaelis menten curve
    • chart?chf=bg,s,00000000&cht=tx&chl=%5BS%5D*V%20%3D%20%5Cfrac%7BVmax%7D%7BKm%7D%5BS%5D&chs=280x68
    • Image Upload 1
  9. 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)
  10. CK-MB tissue source, diagnostic
    • Tissue source: heart, skeletal muscle
    • diagnostic: myocardial infarction (MI)
  11. CK-MM tissue source, diagnostic
    • tissue source: muscle
    • diagnostic: skeletal muscle disorder, muscular dystrophy
  12. CK-BB tissue source, diagnosis
    • tissue source: brain
    • diagnostic: CNS damage, tumors
  13. 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
  14. LD assay mechanism
    • lactatee + NAD+ --> LD--> pyruvate +NADH + H+
    • rate of reverse reaction is 3 times faster
  15. LD 1 (HHHH)
    LD 2 (HHHM)
    tissue source and diagnostic
    • tissue source: heart, RBC
    • diagnostic: MI, anemia, hemolyzed specimen
  16. LD 3 (HHMM)
    tissue source, diagnostic
    • tissue source: lung
    • diagnostic: pulmonary disorder, acute pancreatitis, carcinoma
  17. LD4 (HMMM)
    LD5 (MMMM)
    tissue, diagnostic
    • tissue source: liver, skeletal muscle
    • diagnostic: hepatic injury, skeletal muscle injury
  18. normal LD pattern
    Image Upload 2
  19. abnormal LD pattern
    • Suggestive AMI
    • hemolytic anemia
    • Image Upload 3
  20. AST sample collection
    • stable at 4C and 20C
    • avoid hemolysis
  21. aspartate aminotransferase (AST)
    f(x), tissue source, diagnosis
    • f(x): transferase
    • tissue source: liver
    • diagnosis: hepatocellular disorders, skeletal muscle disorders
  22. alanine aminotransferase (ALT)
    f(x)
    tissue source
    diagnostic
    • f(x): transferase
    • tissue source: liver
    • diagnostic: liver damage
  23. ALT sample requirement
    • heparinized, EDTA plasma acceptable
    • slightly affected by hemolysis
  24. alkaline phosphotase (ALP)
    f(x) 
    tissue source
    diagnostic
    • f(x): hydrolase at an alkaline pH
    • tissue source: liver, bone
    • diagnostic: hepatobiliary, bone disorders
  25. ALP sample requirement
    • 4C for several hours
    • slightly affected by hemolysis
  26. ACP sample requirement
    sample should be frozen or acidified to a pH < 6.5
  27. Acid phosphatase (ACP)
    f(x)
    tissue source
    diagnostic
    • f(x): hydrolase in acid pH
    • tissue source: liver, bone
    • diagnostic: detection for prostatic carcinoma
  28. γ-glutamyltransferase (GGT)
    f(x)
    tissue source:
    diagnostic
    • f(x) transferase
    • tissue source: liver
    • diagnostic: alcoholism
  29. GGT sample requirements
    stable with no loss of activity for 1 week
  30. 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
  31. amylase sample requirement
    Rm temp for 1 week or 4C for 2 months
  32. 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
  33. lipase sample requirement
    • rm stable for 1 week 
    • 4C for 3 weeks
    • avoid hemolysis
  34. enzymes requiring Mg2+ cofactor
    • all CKs and fractions
    • ALP
    • ACP
  35. enzymes requiring NAD+ cofactor
    all LD and fractions
  36. enzyme requireing pyridoxal 5' phosphate (P5P)
    • AST
    • ALT
  37. enzyme requiring gly-gly
    GGT
  38. enzyme requiring Ca2+, Cl-
    amylase
  39. enzyme that has no cofactors
    lipase
Author
tanyalequang
ID
343140
Card Set
Enzyme
Description
co-factor, co-enzymes how to measure enzymes
Updated