Ldh

Question 1

Major tissue source of LDH

Answer 1

Heart
Erythrocytes
Liver
Kidney

Question 2

LDH is found in small amount in

Answer 2

Smooth muscle
Brain
Lungs

Question 3

Elevated surem levels of LDH id observed in (?)

Answer 3

Myocardial infarction
Liver disease
Renal disease
Certain forms of anemia
Malignant diseases
Progressive muscle dystrophy

Question 4

Lactate and pyruvate offers a number of advantages such as

Answer 4

Better reagent stability
Elemintaion of pre-incubation in the procedure
Rate of reaction being linear to a wide range
Less contamination of NAD with inhibiting products

Question 5

Catalyzes the oxidation of lactate to pyruvate in the presence of NAD

Answer 5

Lactate dehydrogenase

Question 6

Wavelength of LDH

Answer 6

340 nm

Question 7

Forward reaction pH of LDH

Answer 7

8.3 - 8.9

Question 8

Reverse reaction pH of LDH

Answer 8

7.1 - 7.4

Question 9

Advantages of reverse reaction

Answer 9

Small volume
Short incubation time

Question 10

Disadvantages of reverse reaction

Answer 10

Prone to substrate exhaustion
Loss of linearity

Question 11

LDH does not act on (?) and only (?) acts as the coenzyme

Answer 11

D-lactate
NAD

Question 12

In lactate dehydrogenase reaction, the (?) formed will proceed to the (?) pathway for generation of energy

Answer 12

Pyruvate
Embden-meyerhoff pathway

Question 13

With the oxidation of lactate to pyruvate, pyruvate and NADH are formed

Answer 13

Colorimetric method based on Wacker

Question 14

In the Colorimetric method based on wacker, a mixture of (1) and (2) reacts with NADH to produce (3) colored compound

Answer 14

1 Phenazine methosulfate
2 nitroblue tetrazolium
3 Blue

Question 15

conversion of pyruvate to lactate by LDH with the presence of NADH

Answer 15

Wroblewski and La due
pH 7.4 - 7.8

Question 16

The rate of reverse reaction in wrobleski and la due is (?) times faster than forward reaction allowing (advantages)

Answer 16

three
smaller volume samples and Shorter reaction time

Question 17

Methods for separation and quantitation of LDH isoenzyme

Answer 17

1 Electrophoresis
2 Column chromatography
3 Immuno-inhibition
4 Babson’s method
5 Kaplan and Berger
6 using alpha-hydroxybutyrate as a substrate

Question 18

Separates isoenzyme based on their anodal rate of migration in an electrophoretic field

Answer 18

Electrophoresis

Question 19

(LDH Isoenzyme)
Migrates the fastest in electrophoresis

Answer 19

LDH1

Question 20

(LDH Isoenzyme)
Migrates the lowest in electrophoresis

Answer 20

LDH6

Question 21

In electrophoresis, an LDH bound to immunoglobulin such as IgA and IgG migrate between (?)

Answer 21

LDH3 and LDH4

Question 22

Method employed for isolation of LDH1 and LDH2 for screening of AMI

Answer 22

Column chromatography

Question 23

Isoenzymes being isolated during the screening of AMI in column chromatography

Answer 23

LDH1 and LDH2

Question 24

Method used for the isolation of LDH1 (only)

Answer 24

Immuno-inhibition

Question 25

Only isoenzyme that does not contain the M subunit of LDH

Answer 25

LDH1

Question 26

Measures the ratio of LDH1 and LDH5

Answer 26

Babson’s method

Question 27

Inhibits the LDH1 in Babson’s method

Answer 27

M-lactate

Question 28

Inhibits the LDH5 in Babson’s method

Answer 28

M-lactate-1 M urea

Question 29

Involves the determination of LDH1 using the rate of heat production in a batch type of colorimeter

Answer 29

Kaplan and Berger

Question 30

In alpha-hydroxybutyrate, the (?) subunit has greater affinity than the other subunit

Answer 30

H

Question 31

Acute myocardial infarction Rise: ? Peak: ? Elevated for: ?

Answer 31

R: within 12-24h P: 48 - 72h Ef: 10 days

Question 32

Highest concentration of LDH is observe in (conditions/disease)

Answer 32

Pernicious anemia Megaloblastic anemia

Question 33

Increased LDH concentration is also observe in (conditions)

Answer 33

Cardiac, hepatic, skeletal muscle and renal disease

Question 34

The Subunits of LDH

Answer 34

H and M subunits

Question 35

Reagent composition of LDH

Answer 35

L-lithium lactate Buffer (pH 9.0)

Question 36

LDH isoenzyme observe when patients is near death

Answer 36

LDH6

Question 37

LDH is determined by: Mean abs difference/ min x (?)

Answer 37

6592

Question 38

What is the: 1 Number of absorbance readings in LDH? 2 trend of absorbance?

Answer 38

1 three 2 increasing

Question 39

Expected values: (30°C) Males: (?) Females: (?)

Answer 39

M: 50 - 166 U/L F: 60 - 132 U/L

Question 40

Expected values: (37°C) Males: (?) Females: (?)

Answer 40

M: 80 - 285 U/L (37°C F: 103 - 227 U/L (37°C)

Question 41

Linearity of LDH

Answer 41

800 U/L

Question 42

Preferred specimen

Answer 42

Fresh unhemolyzed serum

Question 43

Frozen samples show decreased activity of isoenzyme (?)

Answer 43

LD-4 and LD-5

Question 44

Inhibits LDH assay (Additives)

Answer 44

Heparin Citrate Oxalate

Question 45

Type of serum samples that require a serum blank

Answer 45

Icteric and lipemic samples

Question 46

Most heat stable LDH isoenzyme

Answer 46

LDH2

Question 47

Fastest LDH isoenzyme (anodal)

Answer 47

LDH1

Question 48

Most labile LDH isoenzyme

Answer 48

LDH5

Question 49

Intermediate LDH isoenzyme in terms of electrophoretic mobility

Answer 49

LDH3

Question 50

Most predominant LDH isoenzyme in the serum

Answer 50

LDH2