CC1 Flashcards
Enumerate Prostate Enzymes
ACP
G-6-PDH
Enumerate Miscellaneous Enzymes
5’ nucleotidase
Cholinesterase/pseudocholinesterase
Angiotensin Converting Enzyme (ACE)
Ceruloplasmin
Ornithine Carbamoyl Transferase (OCT)
G-6-PD
a phosphoric monoester hydrolase
5’ N
5’ N source
predominantly secreted by the liver
Marker for hepatobiliary disease and infiltrative lesions of the liver
5’ N
5’ N is a marker for these conditions
Hepatobiliary disease
Infiltrative lesions of the liver
reference range for 5’N
0-1.6 units
index of parenchymal function of the liver
Cholinesterase/
Pseudocholinesterase
Cholinesterase/Pseudocholinesterase source
Liver
Monitor effects of muscle relaxants (succinylcholine) after surgery
Cholinesterase/
Pseudocholinesterase
Marker for insecticide/pesticide poisoning (organophosphate – poisonous agent)
Cholinesterase/
Pseudocholinesterase
reference range for cholinesterase/pseudocholinesterase
0.5-1.3 units (plasma)
a.k.a Peptidyldipeptidase A or Kininase II
Angiotensin Converting Enzyme (ACE)
aka Angiotensin Converting Enzyme (ACE)
Peptidyldipeptidase A or Kininase II
Converts angiotensin I to angiotensin II within the lungs (RAAS)
ACE
Primary enzyme of RAAS
Angiotensin Converting Enzyme (ACE)
Promotes vasoconstriction of the renal arterioles to increase blood pressure and stimulates the adrenal cortex to release aldosterone so that aldosterone will promote Na reabsorption
Angiotensin II
Events that activates RAAS
Blood pressure/volume is decrease
Low plasma sodium level
source of ACE
Macrophage and epithelioid cells of the lungs
Possible indicator of neuronal dysfunction
(Alzheimer’s/neurodegenerative disease)
ACE
ACE is increased in these conditions
Sarcoidosis
Acute and chronic bronchitis
Leprosy
Copper-carrying protein which acts as an enzyme
Ceruloplasmin
Marker for Wilson’s disease (hepatolenticular disease)
Ceruloplasmin
Clin. significance of Ornithine Carbamoyl Transferase (OCT)
Hepatobiliary diseases
Reference range for Ornithine Carbamoyl Transferase (OCT)
8-20 mU/mL
Maintain NADPH in the reduced form in the RBCs
G-6-PD
Specimen for G6PD
Red cell hemolysate
Serum
Responsible for maintaining and stabilizing
the membrane integrity of RBCs
reduced NADH (maintained by G6PD)
Protects RBCs from toxic agents that can
induce hemolytic reactions
Reduced NADH (maintained by G6PD)
Sources of G6PD
• Adrenal cortex
• Spleen
• RBC
• Lymph nodes
Enzyme used as a newborn screening marker
G6PD
G6PD is INCREASED in these conditions
MI
Megaloblastic anemia
G6PD is DECREASED in these conditions
Drug-induced hemolytic anemia (intake of primaquine, antimalarial drugs)
Reference range for G6PD
10-15 U/g Hgb
1200-2000 mU/mL pRBC
Biologic intracellular proteins that catalyze biochemical reactions
Enzymes
Affects the reaction of the organic matter
Enzymes
NOT consumed/changed in composition (only substrate → product)
Enzymes
Increased enzymes in serum is due to the following conditions
Cell injury/degradation
Increased membrane permeability
Organ damage (severely increased enzyme in serum/plasma)
What happen when there is an increased membrane permeability?
INCREASED ENZYMES in serum, allowing these proteins to move out easily from the cells
Enzymes are found in _____________
all body tissue (intracellular)
Concentration in serum is very low as it is very abundant in cytoplasm
Enzymes
Indication when there is a SEVERELY INCREASED enzyme in serum/plasma
Organ damage
FUNCTION OF ENZYMES
- Hydration of Carbon Dioxide (respiration)
- Nerve Induction (fast nerve impulse transmission)
- Muscle Contraction (locomotion)
- Nutrient Degradation (digestion)
- Growth and Reproduction (work with hormones)
- Energy Storage and Use
Enzymes with similar catalytic activity, but differ in their physical, biochemical, and immunologic properties
Isoenzymes
What are the difference between enzymes and its isoenzymes?
physical, biochemical, and immunologic properties
What is the similarity between enzymes and its isoenzymes?
catalytic activity
Type of cofactor that serve as a second substrate for enzyme
COENZYME
coenzyme tightly bound to an enzyme
Prosthetic group
T/F
If there is a coenzyme in the reaction, enzyme involved is oxidoreductase – ends with “dehydrogenase” (promotes redox reaction)
T
Part of the reagent since the primary enzyme is the target in the serum
Secondary coupling/indicator enzyme
Requires a coenzyme: pyridoxal phosphate/Vit B6
Aminotransferases
Coenzyme required by aminotransferases
pyridoxal phosphate/Vit B6
A cofactor that enhances enzyme activity by altering the spatial configuration of the active site of enzyme or
enhanced substrate finding
Activator
Types of cofactor
Coenzyme
Activator
These can be grouped as metallic or nonmetallic
Activators
Metallic activators
Mg, Iron, Zinc, Ca
Nonmetallic activators
Cl, Br
when used as coenzyme, it is converted into two forms when acted upon by oxidoreductase
NAD
Oxidized form acted upon by Oxidoreductase
NAD
Reduced form acted upon by Oxidoreductase
NADH
Measured absorbance if the product is OXIDIZED form
NAD
Measured: DECREASE in absorbance
Measured absorbance if the product is REDUCED form
NADH
Measured: INCREASE (HIGH) in absorbance
Enumerate liver enzymes
AST/SGOT
ALT/SGPT
GGT
ALP/Alkaline Orthophosphoric Monoester Phosphohydrolase
ACP/Acid Orthophosphoric Monoester Phosphohydrolase
5’ N
Enumerate cardiac enzymes
CK
LDH
AST
Enumerate non-enzymatic cardiac markers
Myoglobin
Troponins
Enumerate pancreatic enzymes
AMS
LPS
Type of enzyme:
Aspartate Aminotransferase (AST)/
Serum glutamic-oxaloacetic
transaminase (SGOT)
TRANSFERASE
Type of enzyme:
Alanine Aminotransferase (ALT)/
Serum glutamic-pyruvic
transaminase (SGPT)
TRANSFERASE
Type of enzyme:
Gamma-Glutamyltransferase
(GGT)
TRANSFERASE
Type of enzyme:
Acid Phosphatase (ACP)/
Acid Orthophosphoric Monoester
Phosphohydrolase
HYDROLASE
Type of enzyme:
Alkaline Phosphatase (ALP)/
Alkaline Orthophosphoric
Monoester Phosphohydrolase
HYDROLASE
Type of enzyme:
CK/CKP
TRANSFERASE
Type of enzyme:
LDH
OXIDOREDUCTASE
Type of enzyme:
5’ nucleotidase (5’N)
phosphoric monoester HYDROLASE
Type of enzyme:
Amylase (AMS)
HYDROLASE
Type of enzyme:
Lipase (LPS)
HYDROLASE
Transfer of an amino group between aspartate and α-keto glutaric acid
Aspartate Aminotransferase (AST)/
Serum glutamic-oxaloacetic transaminase (SGOT)
Involved in the synthesis and degradation of
AA (protein catabolism, deamination)
Aspartate Aminotransferase (AST)/
Serum glutamic-oxaloacetic
transaminase (SGOT)
Major organ affected of AST/SGOT
HEART
Substrate for AST/SGOT
Aspartic acid (aspartate)
a-ketoglutaric acid (a-ketoglutarate)
End products of AST/SGOT
Glutamic acid (glutamate)
Oxaloacetic acid (oxaloacetate)
Color developer for AST/SGOT
2,4 DNPH
(2,4-Dinitrophenylhydrazine)
Color intensifier for AST/SGOT
0.4 N NaOH
Colorimetric method
for aminotransferase
Reitman and Frankel
Major source of AST/SGOT
Heart
T/F
AST/SGOT is widely distributed
T
Tissue sources of AST/SGOT with increased activities
- Cardiac tissue
- Liver
- Skeletal muscle
AST/SGOT is increased in these conditions
- AMI
- Hepatocellular disorder: chronic liver disorder with progressive damage
- Skeletal muscle disorder: muscular dystrophy (Duchenne)
- Trichinosis
Enzyme increased in
chronic liver disorder with progressive damage
AST/SGOT
(a hepatocellular disorder)
Enzyme increased in muscular dystrophy (Duchenne)
AST/SGOT
Enzyme increased in Trichinosis
AST/SGOT
Isoenzymes of AST/SGOT
Cytoplasmic AST
Mitochondrial AST
most abundant AST isoenzyme in normal serum
Cytoplasmic AST
AST isoenzyme present in mitochondrial membrane
Mitochondrial AST
AST isoenzyme that is increased in cell necrosis
Mitochondrial AST
Assay for AST/SGOT
KARMEN METHOD
2°/indicator enzyme used in Karmen method for AST
Malate Dehydrogenase
Coenzyme used in Karmen method for AST
Pyridoxal phosphate/Vit B6
Monitored in Karmen method for AST and the wavelength used
decrease in absorbance at 340 nm
(measures oxidized NAD)
Variables in Karmen method? What will be the effect?
Hemolysis (False ↑) – very sensitive
Reference range for AST/SGOT using Karmen method
5 – 30 U/L
T/F
Product formed by the 1° enzyme (AST) will become the substrate for the 2° enzyme (MD)
T
In Karmen method, what is the substrate used by MD which is also the product formed by the primary enzyme AST?
oxaloacetate
In Karmen method, what are the products formed acted upon by MD?
malate + NAD
Transfer of an amino group between alanine
and α-ketoglutarate
Alanine Aminotransferase (ALT)/
Serum glutamic-pyruvic transaminase (SGPT)
More liver specific than AST
Alanine Aminotransferase (ALT)/
Serum glutamic-pyruvic
transaminase (SGPT)
Major organ affected by ALT/SGPT
LIVER
Substrates used by ALT/SGPT
Alanine
a-ketoglutaric acid (a-ketoglutarate)
End products of ALT/SGPT
Glutamic acid (glutamate)
Pyruvic acid (pyruvate)
Color developer for ALT/SGPT
2,4 DNPH
Color intensifier for ALT/SGPT
0.4 N NaOH
Major source of ALT/SGPT
LIVER
Minor sources of ALT/SGPT
- Kidneys
- Pancreas
- RBC
- Heart
- Skeletal muscle
- Lungs
ALT/SGPT is increased in these conditions
- Hepatocellular disorders
(liver specific enzyme) - Acute liver inflammation
Enzyme used to monitor hepatitis treatment
and drug therapy effects
ALT/SGPT
Enzyme used to screen post transfusion hepatitis
ALT/SGPT
Screens blood donors (not routine; only with jaundice)
ALT/SGPT
Sensitive test for
occupational toxic exposure
ALT/SGPT
Assay for ALT/SGPT
LACTATE DEHYDROGENASE (LD)
2°/indicator enzyme for ALT/SGPT assay
LACTATE DEHYDROGENASE (LD)
Coenzyme used in LD for ALT
Pyridoxal phosphate/Vit B6
Monitored in LD for ALT? What is the wavelength?
decrease in absorbance at 340 nm
(measures oxidized NAD)
Reference range for ALT using LD assay
6 – 37 U/L
In LD assay, what is the substrate used by LD which is also the product formed by the primary enzyme ALT?
pyruvate
In LD assay for ALT, what are the products formed by LD?
lactate + NAD
aka De Ritis Ratio
AST/ALT Ratio
SGOT/SGPT Ratio
Used to differentiate the cause of hepatic disorder
De Ritis Ratio (AST/ALT Ratio)
De Ritis Ratio (AST/ALT Ratio):
> 1
nonviral origin
De Ritis Ratio (AST/ALT Ratio):
<1
viral origin
what is the cause of hepatic disorder when the AST is higher than ALT?
non-viral
>1 (high AST: low ALT)
what is the cause of hepatic disorder when the ALT is higher than AST?
viral
<1 (low AST: high ALT)
T/F
In De Ritis Ratio, a ratio of exactly 1 is possible.
FALSE!
Ratio of 1 is not possible because AST has MANY tissue sources
Catalyze transfer of γ-glutamyl residue from γ-glutamyl peptides to amino acids, H20, etc.
Gamma-Glutamyltransferase
(GGT)
Common donor (biologic system) in GGT
glutathione
Substrates used in GGT
Glutathione + AA
Products formed when GGT is used as an enzyme
glutamyl-peptide +
L-cysteinylglycine
Source of GGT
Canaliculi of hepatic cells, specifically in the
epithelial lining of biliary ductulus
GGT is used to diagnose these conditions
Hepatobiliary disorders (obstructive jaundice)
Chronic alcoholism (ethanol intoxication)
Marker for occult alcoholism
GGT
Most sensitive marker for acute alcoholic hepatitis
GGT
Assay for GGT
SZAZ ASSAY
measures the absorbance of p-nitroaniline at 405-420 nm
SZAZ ASSAY for GGT
Wavelength used in Szaz assay to measure p-nitroaniline
405-420 nm (visible light region)
T/F
Wavelength requirement may be a clue to the detected product
T
400-700 nm – visible light region
Nonvisible regions:
<400 – UV region
>700 – IR region
