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Question 1

NAD MEANS

Answer 1

nicotinamide adenine dinucleotide (NAD)

Question 2

A coenzyme is an organic
cofactor, such as nicotinamide adenine dinucleotide (NAD). When bound tightly
to the enzyme, the coenzyme is called a prosthetic group.

Answer 2

T

Question 3

Oxidoreductases. Catalyze an oxidation–reduction reaction between two
substrates
2. Transferases. Catalyze the transfer of a group other than hydrogen from
one substrate to another
3. Hydrolases. Catalyze hydrolysis of various bonds
4. Lyases. Catalyze removal of groups from substrates without hydrolysis; the
product contains double bonds
5. Isomerases. Catalyze the interconversion of geometric, optical, or
positional isomers
6. Ligases. Catalyze the joining of two substrate molecules, coupled with
breaking of the pyrophosphate bond in adenosine triphosphate (ATP) or a
similar compound

Answer 3

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Question 4

Oxidoreductases

Answer 4

LDH
G6PD

Question 5

TRANSFERASES

Answer 5

AST
ALT
GGT
CK

Question 6

HYDROLASES

Answer 6

ALP
ACP
AMYLASE

Question 7

CK level is considered a
sensitive indicator of acute myocardial infarction (AMI) and muscular
dystrophy, particularly the Duchenne type.

Answer 7

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Question 8

Elevated CK levels are also occasionally seen in central nervous system
disorders such as cerebrovascular accident, seizures, nerve degeneration, and
central nervous system shock. Damage to the blood–brain barrier must occur to
allow enzyme release to the peripheral circulation.

Answer 8

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Question 9

CK-BB will migrate fastest toward the
anode and is therefore called CK-1. CK-BB is followed by CK-MB (CK-2) and,
finally, by CK-MM (CK-3), exhibiting the slowest mobility

Answer 9

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Question 10

The major isoenzyme in the sera of healthy people is the MM form. Values
for the MB isoenzyme range from undetectable to trace (<6% of total CK

Answer 10

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Question 11

CK-MM is the major isoenzyme fraction found in striated muscle and
normal serum.

Answer 11

20% a result of CK-MB.
7 Normal serum
consists of approximately 94% to 100% CK-MM

Question 12

CK-BB level is greater than 5 U/L, usually
in the range of 10 to 50 U/L.

CK-BB activity below 10 U/L.

Answer 12

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Question 13

troponin is the
preferred marker to detect MI because it is the most sensitive and specific for
myocardial damage.

Answer 13

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Question 14

Macro-CK appears to migrate to a position midway between CK-MM and
CK-MB.

IgG

Answer 14

Mitochondrial CK (CK-Mi) is bound to the exterior surface of the inner
mitochondrial membranes of muscle, brain, and liver.

It migrates to a point
cathodal to CK-MM and exists as a dimeric molecule of two identical subunits.

Question 15

healthy individuals, the major isoenzyme fraction is LDH-2,
followed by LDH-1, LDH-3, LDH-4, and LDH-5

LDH-6 is alcohol dehydrogenase

Answer 15

serum levels of LDH-1
will increase to a point at which they are present in greater concentration than
LDH-2, resulting in a condition known as the LDH flipped pattern (LDH-1 >
LDH-2).
19 This flipped pattern is suggestive of AM

Question 16

LDH is commonly used to measure lactic and pyruvic acids or as a coupled
reaction

the forward reaction is 8.3 to 8.9; for the reverse reaction, it is 7.1 to 7.

Answer 16

LDH-5 is the most
labile isoenzyme.

LDH, 125–220 U/L (37°C

Question 17

AST

Pyridoxal phosphate functions as a coenzyme

AST elevations are frequently seen in pulmonary embolism. Following
congestive heart failure

Answer 17

cytoplasmic isoenzyme is the
predominant form occurring in serum.

Karmen
method, which incorporates a coupled enzymatic reaction using malate
dehydrogenase (MD) as the indicator reaction and monitors the change in
absorbance at 340 nm continuously as NADH is oxidized to NAD+
The optimal pH is 7.3 to 7.8.

AST, 5–35 U/L (37°C)

Question 18

ALT

typical assay procedure for ALT consists of a coupled enzymatic reaction
using LDH as the indicator enzyme, which catalyzes the reduction of pyruvate to
lactate with the simultaneous oxidation of NADH. The change in absorbance at
340 nm measured continuously is directly proportional to ALT activity.

The optimal pH is 7.3 to 7.8

Answer 18

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Question 19

most specific substrates for prostatic ACP is thymolphthalein
monophosphate.

prostatic fraction is
inhibited by tartrate.

ACP assays have proved useful in forensic clinical chemistry, particularly in
the investigation of rape. Vaginal washings are examined for seminal fluid–ACP
activity, which can persist for up to 4 days

Answer 19

osteoclasts.
32 Elevations have been noted
in Paget’s disease, in breast cancer with bone metastases, and in Gaucher’s
disease, in which there is an infiltration of bone marrow and other tissue by
Gaucher cell

The reaction products are colorless at the acid pH of the reaction

Thymolphthalein monophosphate
is the substrate of choice for quantitative end point reactions. For continuous
monitoring methods, α-naphthyl phosphate is preferred.

Question 20

ACP

Serum activity decreases within
1 to 2 hours if the sample is left at room temperature without the addition of a
preservative

should
be frozen or acidified to a pH lower than 6.5. With acidification, ACP is stable
for 2 days at room temperature. Hemolysis should be avoided because of
contamination from erythrocyte ACP.

Prostatic ACP, 0–3.5 ng/mL
Tartrate-resistant ACP, adults: 1.5–4.5 U/L (37°C); children: 3.5–9.0 U/L
(37°C

Answer 20

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Question 21

GGT

elevations are generally observed in biliary tract obstruction

GGT levels will be increased in patients receiving enzymeinducing drugs such as warfarin, phenobarbital

as acute pancreatitis,
diabetes mellitus, and myocardial infarction. The source of elevation in
pancreatitis and diabetes is probably the pancreas,

Answer 21

accepted substrate for use in GGT analysis is γ-glutamyl-pnitroanilide. The γ-glutamyl residue is transferred to glycylglycine, releasing pnitroaniline, a chromogenic product with a strong absorbance at 405 to 420 nm

GGT activity is stable, with no loss of activity for 1 week at 4°C. Hemolysis
does not interfere with GGT levels because the enzyme is lacking in
erythrocytes.

GGT: male, 6–55 U/L (37°C); female, 5–38 U/L (37°C)