METHODS FOR GLUCOSE MEASUREMENT & OTHER CLINICAL CORRELATIONS Flashcards
Chemical methods for measuring glucose levels:
- Oxidation-reduction methods
- Condensation method (Dubowski)
Alkaline copper reduction methods:
- Folin-Wu
- Nelson-Somogyi
- Neocuproine method
- Benedict’s method
Cu + phosphomolybdate —-> PM blue (phosphomolybdenum)
what alkaline copper reduction reaction is shown above?
Folin-Wu method
Cu + arsenomolybdate —-> AM blue (arsenomolybdenum)
what alkaline copper reduction reaction is shown above?
Nelson-Somogyi method
Enzymes used in measuring glucose levels:
- Glucose oxidase
- Hexokinase
Most specific enzyme reacting with only B-D-glucose:
Glucose oxidase
Two ways in which glucose oxidase can be measured:
- Colorimetric method
- Polarographic method
Measures the rate of disappearance of oxygen using oxygen electrode in glucose oxidase method:
Polarographic method
Glucose oxidase method that uses a side reaction that uses H2O2:
Colorimetric method
What enzyme is used in the side reaction for colorimetric method?
Peroxidase
This method is more accurate than glucose oxidase methods, because the coupling reaction using G6PDH is highly specific:
Hexokinase method
What is measured in Hexokinase method?
NADPH
NADPH is has a strong affinity and measured at the wavelength of:
340 nm (UV)
Is Hexokinase method affected by ascorbic acid or uric acid?
NO. The hexokinase method is NOT affected by ascorbic or uric acid.
Most common cause of lactose intolerance:
Lactase deficiency
Why does lactase intolerance causes watery diarrhea?
Lactose is not digested. Lactose retains water
Glycogen storage disease with a defective enzyme glucose-6-phosphatase:
Von Gierke Disease
Enumerate Glycogen Storage Diseases:
- Type I - Von Gierke
- Type II - Pompe
- Type III - Cori
- Type IV - Andersen
- Type V - McArdle
- Type VI - Hers
- Type VII - Tarui disease
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What type of glycogen storage disorder wherein the defective enzyme is a-1,4-glucosidase:
Type II Pompe
Defective enzyme in type III (Cori) glycogen storage disease:
debranching enzyme
Defective enzyme in type IV (Andersen) glycogen storage disease:
Branching enzyme
Organ affected in Type V (McArdle) glycogen storage disease:
Muscle
Organ affected in Type VI (Hers) glycogen storage disease:
Liver
Enzyme defective in Type VII (Tarui) glycogen storage disease:
Phosphofructokinase
In Folin-Wu method, what reacts with Cu+ (cuprous ion) to form PM blue?
Phosphomolybdate
In Nelson-Somogyi, what reacts with Cu+ (cuprous ion) to form AM blue?
Arsenomolybdate
