ENZYMOLOGY Flashcards
Uses olive oil or triolein as substrate ( TAG + H2O in the presence of LIPASE will produce GLYCEROL and FATTY ACIDS) FA will be SUBSEQUENTLY TITRATED
Cherry-crandall method (LIPASE DETERMINATION)
Measures the rate of clearing as fats are hydrolyzed by LPS
TURBIDIMETRIC METHOD ( LPS DETERMINATION)
Based on coupled reactions with Glycerol Kinase and Peroxidase ( detection of glycerol)
Colorimetric methods (LPS determination)
Reference value for LPS
<38 U/L
Significance:
Hepatolbilliary disorders, Alcoholic Liver Disease, Microsomal induction by drugs and alcohol; also used to ID the source of increased ALP
GAMMA GLUTAMYL TRANSFERASE (GGT)
>GGT and 5NT = hepatolbilliary disorders
Normal GGT and >5NT = Biliary obstruction
Best enzymatic marker for ALCOHOLISM
GGT
Clinical significance:
INTRAHEPATIC CHOLELSTASIS
also use to ID source of elevated ALP
5` Nucleotidase
Major source of ACP
Prostate, RBCs
Significance of ACP
Prostatic Cancer, hyperplasia, RAPE CASES
ACP determination
Roy method:
Substrate: Thymophthalein Monophosphate
CHEM. INHIBITION:
- TARTRATE ( - prostatic ACP)
- COPPER AND FORMALDEHYDE (- RBC ACP)
Aldolase significance
Skeletal muscle disorders
Enzyme responsible for BP regulation
Angiotensin converting enzyme (ACE)
Glycogen phosphorylase significance
AMI
Pancreatic marker
Increased in acute pancreatic insufficiency
And decreased in chronic pancreatic insufficiency
Trypsin
Miscellaneous enzymes that are only significant when increase
ACP
ALDOLASE
GUTAMATE DH
GLUTARHIONE-S-T
ACE
GLYOCGEN PHOSPHORYLASE
TRYPSIN
Miscellaneous enzymes that are only significant when decrease
Chymotrypsin/Elastase 1
G-6-PD
PK
pseudo ChE
Clinical significant if decreased in the following conditions
Chronic pancreatic insufficiency
Steatorrhea
Undigested muscle fibers
Chymotrypsin/Elastase 1
Miscellaneous enzyme decreased in drug induced hemolytic anemia
G-6-PD
Clinical significant of PYRUVATE KINASE
If decreased, in Hemolytic disorders such as Hemolytic anemia secondary to membrane abnormality. Congenital echinocytosis
Significance of Pseudo ChE
When decreased in SERUM, Pesticide poisoning, Liver disease, Genetic variance (prolonged response to muscle relaxants)
O T H L I L
1 2 3 4 5 6
Oxidoreductase
Trnasferases
Hydrolase
Lyases
Isomerase
Ligase
Biologic protein catalyst that accelerates biochemical reactions without being consumed or changed in composition
Enzyme
Catalytic mechanism
E + S <—-> ES complex <—-> P + E
• Substrate <Enzyme
• Enzyme> Substrate
Substrate- rate-limiting component
First-Order Kinetics
• Enzyme <Substrate
• Substrate >Enzyme
Zero-Order kinetics
2 ways to plot Enzyme Activity
Michaelis - menten
Lineweaver-Burke plot
Measurements of enzyme activity or rate of velocity
IU - mmol/minute
Katal - mol/second
“Conversions:
1IU = 0.0167
Ukat = 16. 7
1 kat = 1.6 IU”
Factors that influence enzymatic reaction
pH
Temperature
Cofactors
Inhinitors
Noncompetitive inhibitor
Binding site is allosteric site
Addition of S no effect
Low Vmax
Same Km
Competitive inhibition
Binding site is active site
Addition of Sreverses inhibition
Same Vmax
Low Km
Uncompetitive inhibition
Binding site is ES complex
Addition of S increases the inhibition
Low Vmax and Km
Enzyme + Immunoglobulin
Macro enzyme (type 1)
Enzyme + no immunoglobulin substance
Macro enzyme (type 2)
Enzymes with macro forms
CK
AMS
LD
AST
ACP
ALP
LPS
GGT
Creatinine kinase tissue sources
BRAIN HEART SKELETAL MUSCLES
Creatinine kinase pronounced elevation
Duchenne’s muscular dystrophy, polymyositis,
Dermapolymyositis,
Myocardial infarction
CK isoenzymes
CK1
CK2
MAXRO-CK
CK3
MI
CK determination tests
Tanzer-Gilvarg
Oliver-Rosalki
LDH tissue sources
LD1- Heart, RBCs, Renal Cortex
LD2 - same as LD1
LD3 - Lungs, Lymphocytes, Spleen, Pancreas
LD4- liver, skeletal muscle
LD5 - same as LD5
LD6
Alcohol dehydrogenase
CK mild to moderate elevation
Acute agitated psychosis, alcoholic myopathy, severe exercise, delirium tremens, severe ischemic Injury, pulmonary infarction, intramuscular injection, hypothyroidism
