Class 1 Enzymes

Question 1

LD (lactate Dehydrogenase) is a metalloenzyme because it contains

Answer 1

Zinc

Question 2

What is the coenzyme of LD?

Answer 2

NAD

Question 3

Forward reaction of LD has a optimal pH of?

Answer 3

8.8-9.8

Question 4

Backward reaction of LD has an optimal pH of?

Answer 4

7.4-7.8

Question 5

Lactate + NAD ——LD—-> Pyruvate + NADH + H is what type of reaction?

Answer 5

Forward reaction

Question 6

Pyruvate + NADH + H ——LD—-> Lactate + NAD is what type of reaction?

Answer 6

Backward or Reverse reaction

Question 7

Very high activities of LD is seen in what organ?

Answer 7

Heart
RBCs
Kidney
Liver
Skeletal muscles

Question 8

Lesser amounts of LD is seen in what organs

Answer 8

Lungs
Smooth muscles
Brain

Question 9

LD1 and LD2 are found in what tissue organs?

Answer 9

Heart
RBCs
Kidney

Question 10

If LD1/LD2 is increased, what are the suspected disorders?

Answer 10

Myocardial Infarction
Hemolyzed specimen
Megaloblastic anemia
Hemolytic anemia
Acute renal infarction

Question 11

In serum, what LD isoenzyme is seen in high amounts

Answer 11

LD2

Question 12

What LD isoenzymes are considered heat stable?

Answer 12

LD1, LD2, & LD3

Question 13

Most negatively charged isoenzyme?

Answer 13

LD1

Question 14

LD3 is found in which organs?

Answer 14

Lungs (major)
Lymphocytes
Spleen
Pancreas

Question 15

This type of isoenzyme is increased or elevated in any type of cancer

Answer 15

LD3

Question 16

Among all types of isoenzymes which is considered the least specific?

Answer 16

LD3

Question 17

If the patient has pneumonia, what isoenzyme is suspected to be elevated?

Answer 17

LD3

Question 18

The patient has lympocytosis, what isoenzyme is elevated?

Answer 18

LD3

Question 19

Which isoenzyme is considered to be heat and cold labile?

Answer 19

LD4 & LD5

Question 20

Injury of the liver or skeletal muscle will cause elevation of?

Answer 20

LD4 & LD5

Question 21

This isoenzyme os found in human testis and sperm

Answer 21

LDX (XXXX)/(CCCC)

Question 22

Isoenzyme LD6 is also known as

Answer 22

Arterosclerotic cardiovascular failure
Alcohol dehydrogenasse

Question 23

True or False
Non-hemolyzed sample needed in testing LD

Answer 23

True
—> kasi RBCs have LD, so hemolyzed samples will cause false elevation.

Question 24

LDH is inhibited by?

Answer 24

Sulfhydryl reagents
EDTA
Excess pyruvate and lactate
Borate and oxalate

Question 25

This method measure the forward reaction of LD

Answer 25

Wacker Method

Question 26

This method measure the backward reaction of LD

Answer 26

Wroblewski-Ladue method

Question 27

True or False LD2 is normally higher than LD1

Answer 27

True

Question 28

Reference range of LD

Answer 28

Pyruvate to Lactate = 80-280 U/L at 37C Lactate to Pyruvate = 100-225 U/L at 37C

Question 29

How long does it take for total LD to rise after onset of chest pain?

Answer 29

12-24 hours

Question 30

How long does it take for the total LD to reach its peak?

Answer 30

48-72 hours

Question 31

Total LD remains elevated for how long after onset of chest pain?

Answer 31

10 days

Question 32

Myocardial infarction is suspected when there is flipped in LD pattern (LD1>LD2) followed by the presence of?

Answer 32

CK2 —> pag walang CK2 most probably and caused ng flipped LD pattern ay hemolysis or renal infarction

Question 33

This is needed by the red blood cells to maintain integrity of the cell membrane structure

Answer 33

NADPH

Question 34

This is needed as starting material for nucleotide and nucleic acid synthesis

Answer 34

Pentose Phosphate

Question 35

This catalyzes the oxidation of glucose 6- phosphate to 6-phosphogluconate or the corresponding lactone

Answer 35

G6PD

Question 36

An inherited sex-linked trait that develops hemolysis only when oxidative stress occurs, as with infections and after ingestion of certain drugs or fava bean

Answer 36

G6PD Deficiency

Question 37

G6PD is found in?

Answer 37

Erythrocytes Adrenal cortex Spleen Lymph nodes Lactating mammary gland

Question 38

This acts as a copper transport protein

Answer 38

Ceruloplasmin

Question 39

This catalyzes the oxidation of ferrous iron (Fe2+) to Ferric iron (Fe3+)

Answer 39

Ceruplasmin

Question 40

This disease is characterized by accumulation of copper in several organs such as the eyes leading to Kayse-Fleischer Ring

Answer 40

Wilson’s disease

Question 41

Decreased ceruloplasmin is seen in?

Answer 41

1.) Renal disease associated with protein loss and severe nutritional CHON deficiencies 2.) Wilson’s disease

Question 42

Glycoprotein that binds copper in the plasma

Answer 42

Ceruloplasmin

Question 43

Specimen requirements for testing G6PD

Answer 43

Red cell hemolysate - assay for deficiency of the enzyme Serum - evaluation of enzyme elevations