Enzymes

Question 1

CK isoenzyme found in highest concentration in the blood

Answer 1

CK-MM

Question 2

Type of inhibition wherein the inhibitor attaches itself to the active site of the enzyme

Answer 2

Competitive

Question 3

Inactive enzymes are termed as ___, which are common among digestive enzymes

Answer 3

Proenzymes

Question 4

Most electronegative LD isoenzyme

Answer 4

LD1

Question 5

What are the conditions for zero-order kinetics?

Answer 5

Substrate concentration is higher than enzyme concentration

Question 6

Which LD isoenzyme appears indicative of arteriosclerotic cardiovascular failure?

Answer 6

LD6

Question 7

This enzyme functions is maintain NADPH in a reduced form which is responsible for regenerating sulfhydryl-containing proteins (ie glutathione) from oxidized to reduced state

Answer 7

Glucose-6-phosphate dehydrogenase

Question 8

The slowest moving fraction of CK is typically elevated in patients with:

Answer 8

Skeletal muscle disorders

Question 9

Hemolyzed serum cannot be used for AST determination because:

Answer 9

Erythrocytes contain a large amount of AST

Question 10

Correct arrangement of the classes of enzymes

Answer 10

Oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase

Question 11

Indicator enzyme used in Karmen method

Answer 11

Malate dehydrogenase

Question 12

Chemical inhibition of ALP using Phenylalanine

Answer 12

Inhibits 75% of intestinal and 80% of placental ALP

Question 13

Which enzyme is most useful in identifying the source of ALP elevation?

Answer 13

GGT

Question 14

An amylase method which measures the disappearance of the starch substrate

Answer 14

Amyloclastic

Question 15

What results when an enzyme is subject to post-translational modifications?

Answer 15

Isoform

Question 16

Also known as organic cofactors

Answer 16

Coenzymes

Question 17

What are the classes of enzymes?

Answer 17

Oxidoreductases
Transferases
Hydrolases
Lyases
Isomerases
Ligases

Question 18

In the Michaelis-Menten curve, Km is defined as the:

Answer 18

Substrate concentration at which v is half of Vmax

Question 19

The Km of an enzyme reaction is ____ proportional to the affinity of a substrate to its enzyme.

Answer 19

Inversely

Question 20

In this type of inhibition, increasing substrate concentration further increases inhibition.

Answer 20

Uncompetitive inhibition

Question 21

1 IU can be defined as:

Answer 21

Amount of enzyme that will catalyze the reaction of 1 umol of substrate in 1 minute

Question 22

1 Katal can be defined as:

Answer 22

Amount of enzyme that will catalyze the reaction of 1 mole of substrate in 1 second

Question 23

1 IU = ___ kat

Answer 23

17

Question 24

These conditions cause a pronounced elevation (>5x) in CK measurement.

Answer 24

DMD
Polymyositis
Dermatomyositis
Myocardial infarction

Question 25

In AMI, CK-MB rises within ____ hours, peaks at ____ hours and return to normal within ____ hours.

Answer 25

4-8; 12-24; 48-72

Question 26

The forward reaction of CK determination is also known as:

Answer 26

Tanzer-Gilvarg

Question 27

The reverse reaction of CK determination is also known as:

Answer 27

Oliver-Rosalki (most commonly preferred)

Question 28

Highest levels of LDH elevation are seen in:

Answer 28

Pernicious anemia & hemolytic disorders

Question 29

These conditions cause a pronounced elevation (>5x) in LDH measurement.

Answer 29

``` Megaloblastic anemia Carcinomatosis Systemic shock Hepatitis Renal infarction TTP ```

Question 30

These conditions cause a slight elevation (3x) in LDH measurement.

Answer 30

Liver disease Nephrotic syndrome Hypothyroidism Cholangitis

Question 31

The forward reaction of LDH determination is also known as:

Answer 31

Wacker et al

Question 32

The reverse reaction of LDH determination is also known as:

Answer 32

Wrobleuski & :a Due

Question 33

In AMI, LDH increases within ____ hours, peaks at ____ hours, and remains elevated for ____ days.

Answer 33

12-24; 72; 10

Question 34

LD1 and LD2 are heat-____.

Answer 34

Stable

Question 35

____ acts as the coenzyme for both AST & ALT.

Answer 35

Pyridoxal phosphate

Question 36

In AMI, AST rises within ___ hours, peaks at ____ hours, and returns to normal in ___ days.

Answer 36

6-8; 24; 5

Question 37

These conditions cause a pronounced elevation (>5x) in AST measurement.

Answer 37

Acute hepatocellular damage MI Circulatory collapse IM

Question 38

These conditions cause a slight elevation (>3x) in AST measurement.

Answer 38

``` Pericarditis Cirrhosis Pulmonary infarction Delirium tremens Cerebrovascular accident ```

Question 39

Method of determination for AST

Answer 39

Karmen method

Question 40

Method of determination for ALT

Answer 40

Walker et al

Question 41

Highest activity of ALP is seen in:

Answer 41

Osteitis deformans (Paget's disease)

Question 42

These conditions cause a pronounced elevation (>5x) in ALP measurement.

Answer 42

Bile duct obstruction Biliary cirrhosis Osteogenic carcinoma Hyperparathyroidism

Question 43

Inhibition with ____ reduces the activity of I & P isoenzymes; inhibition with ____ reduces the activity of B & L isoenzymes.

Answer 43

Phenylalanine; levamisole

Question 44

In Bessey-Lowry-Brock & Bowers-McComb ALP determination, ____ is the substrate used.

Answer 44

p-nitrophenylphosphate

Question 45

In Shinowara-Jones-Reinhart ALP determination, ____ is the substrate used.

Answer 45

B-glycerylphosphate

Question 46

In Babson & Reed ACP determination, ____ is the substrate used.

Answer 46

a-naphthylphosphate

Question 47

In Roy ACP determination, ____ is the substrate used.

Answer 47

Thymolphthalein monophosphate

Question 48

Most useful application for GGT measurement:

Answer 48

Detection of alcoholism & monitoring of alcohol consumption during treatment

Question 49

In acute pancreatitis, AMY levels rises at ____ hours, peaks at ____ hours, remains elevated for ____ hours, and returns to normal within ____ days.

Answer 49

2-12; 24-30; 6-72; 3-5

Question 50

These conditions cause a pronounced elevation (>5x) in AMY measurement.

Answer 50

Acute pancreatitis Pancreatic pseudocyst Morphine adminstration

Question 51

What AMY method is used for stat analysis to rule out acute abdominal pain?

Answer 51

Turbidimetry & nephelometry

Question 52

Somogyi unit is defined as the number of mg of glucose in ___ minutes at ___C under specific assay conditions.

Answer 52

30; 37

Question 53

____ inhibits salivary amylase.

Answer 53

Wheat germ lectin

Question 54

In electrophoresis , ____ amylase is more anodal.

Answer 54

Salivary

Question 55

In acute pancreatitis, LIP levels rises at ____ hours, peaks at ____ hours, and remains elevated for ____ days.

Answer 55

2-12; 48-72; 10-14

Question 56

In the Modified Cherry-Crandall method, ____ is used as the substrate instead of olive oil.

Answer 56

Triolein

Question 57

G6PD deficiency is implicated in ____ anemia.

Answer 57

Drug-induced hemolytic

Question 58

This type of cholinesterase hydrolyzes a variety of choline esters and provides a protective function in the body.

Answer 58

Pseudocholinesterase

Question 59

In conditions such as ____, ACHE values are decreased.

Answer 59

Organophosphate poisoning

Question 60

This is a sensitive, rapid, & the recommended method of ACHE determination.

Answer 60

Ellman

Question 61

This is a temperature-sensitive method for ACHE determination, and confers much variability among different labs.

Answer 61

Michel