Clinically important enzymes

Question 1

Amylase is sourced from

Answer 1

the pancreas and salivary glands; splits starch into sugars at alpha linkages.

Question 2

(amylase method) Amyloclastic

Answer 2

Amylase acts on starch substance.
Use iodine to determine amount of substrate remaining.

Question 3

The oldest amylase method or classic reference method is

Answer 3

Sacharogenic, determines amount of sugar produced (product)

Question 4

The method in which amylase hydrolyzes insoluble dye/starch complex increasing absorbance is

Answer 4

Chromogenic; increase in color intensity proportional to amylase activity

Question 5

The amylase method which includes the coupling of several enzyme systems by a continuous monitoring technique is called.

Answer 5

Kinetic method (340nm) optimal pH 6.9

Question 6

Which enzyme hydrolyzes ester linkages of fats to produce alcohols and fatty acids?

Answer 6

Lipases

Question 7

High lipase along with decreased calcium is a

Answer 7

bad prognosis as it indicates that calcium was combined into Ca+ soaps due to high amount of liberated fatty acids.

Question 8

(lipase method) Turbidimetric

Answer 8

Simpler and faster method.
Lipase hydrolyzes fatty emulsion- decrease in absorbance.
Stable substrates are difficult to find- often use triolein.
Bilirubin falsely increases values.

Question 9

Colorimetric

Answer 9

Coupled reactions with enzymes such as glycerol kinase peroxidase

Question 10

Regan and Nagao is

Answer 10

an ALP that is a placental like fetal form which occurs in 3-15% of cancer patients.

Question 11

Macro Ck is comprised of

Answer 11

CK-BB complexed with IgA and IgG

Question 12

Mitochondrial Ck is bound to

Answer 12

Exterior surface of inner mitochondrial membranes of muscle brain and liver

Question 13

What has to occur to see mitochondrial CK?

Answer 13

extensive tissue damage

Question 14

RBCs are rich in

Answer 14

Adenylate kinase which reacts with ADP to produce ATP which participates in assay enzyme reaction, falsely elevating CK levels.

Question 15

GGT is involved in

Answer 15

peptide and protein synthesis
regulation of tissue glutathione levels
transport of amino acids across cell membranes

Question 16

GGT can be helpful differentiating

Answer 16

Source of elevated ALP, as GGT is normal in skeletal disorders and during pregnancy.

Question 17

GGT is lower in females because

Answer 17

of the suppression of enzyme activity resulting from estrogenic or pregestational hormones.

Question 18

Which enzyme has marked elevations for acute lymphoblastic leukemia

Answer 18

LDH

Question 19

LDH forward reaction

Answer 19

Slower ; Lactate to pyruvate

Question 20

LDH reverse reaction

Answer 20

Faster: pyruvate to lactate

Question 21

LDH reactions referred to as

Answer 21

Wacker method

Question 22

LDH isoenzyme’s structure includes:

Answer 22

M and H subunits with 4 chains

Question 23

LDH 1 and LDH 2 are greatest in

Answer 23

Heart and RBCs

Question 24

LDH 4 and LDH 5 are greatest in

Answer 24

Liver and skeletal muscle

Question 25

LDH assay

Answer 25

catalyzes the interconversion of lactic and pyruvic acids using coenzyme NAD+

Question 26

Organophosphates and nerve gases inhibit

Answer 26

cholinesterases

Question 27

Why cant one use RBC hemolysate to measure G-6-PD after a hemolytic episode?

Answer 27

It would be falsely increased due to reticulocytes rich in G-6-PD

Question 28

______ catalyzes the hydrolysis of phosphomonesters at an alkaline pH

Answer 28

Alkaline phosphatase

Question 29

The reaction for AST is

Answer 29

the transfer of an amino group between aspartate and alpha keto acids

Question 30

Pyrodoxal phosphate functions as a

Answer 30

coenzyme for AST

Question 31

Transamination reaction is important as

Answer 31

synthesis and degradation of amino acids

Question 32

Ketoacids

Answer 32

oxidize and provide a source of energy

Question 33

G6PD

Answer 33

is an oxidoreductase that catalyzes the oxidation of glucose 6 phosphate to 6-phosphogluconate - 1st step in glucose metabolism with ultimate production of NADPH

Question 34

Hypothyroidism is associated with which enzyme?

Answer 34

CK-MM

Question 35

This enzyme will be elevated in carcinomas

Answer 35

CK-BB

Question 36

This enzyme will be a significant indicator of Acute myocardial infarction

Answer 36

CK-MB

Question 37

This enzyme will reflect the degree of ischemic heart damage

Answer 37

CK-MB

Question 38

Forward reaction in CK enzyme activity

Answer 38

Pyruvate kinase- LDH- NADH system

Question 39

Reverse reaction in CK enzyme activity

Answer 39

Hexokinase-glucose-6-phosphate dehydrogenase- NADP system

Question 40

Acetylcholinesterase

Answer 40

Destroys acetylcholine after nerve impulse is transmitted.

Question 41

Cholinesterase’s are

Answer 41

a group of enzymes that hydrolyze esters of choline

Question 42

AST can be found in

Answer 42

Human tissue, highest concentration in cardiac tissue, liver, muscle, kidney, pancreas, and erythrocytes

Question 43

A ck value seen in men is ____

Answer 43

46-171 u/L

Question 44

A ck value seen in women is ___

Answer 44

34-145 U/L