CC LEC 2 - Enzymes III

Question 1

Hydrolyzes the ester linkages of fats

(dietary triglycerides)alcohols & fatty acids

Answer 1

LPS

Question 2

Major source of LPS

Answer 2

Pancreas

Question 3

Isoenz of LPS

Answer 3

L1, L2, L3

Question 4

most clinically significant &

sensitive LPS isoenz

Answer 4

L2

Question 5

Detection almost only indicates acute pancreatitis

Answer 5

LPS

Question 6

WHAT ENZ
Intraabdominal conditions:
 Penetrating duodenal ulcers  Perforatedpepticulcers
 Intestinal obstruction
 Acute cholecystitis

Answer 6

LPS

Question 7

LPS activator

Answer 7

albumin/ionized calcium

Question 8

LPS inhibitors

Answer 8

heavy metals (ex. quinine)

Question 9

Substrate of turbidimetric and titrimetric LPS method

Answer 9

olive oil or triolein

Question 10

LPS method
Simpler, more rapid
- Substrate: olive oil or triolein (more
used, pure form of triglycerides)

Answer 10

Turbidimetric Enzyme Reaction

Question 11

LPS method
- Estimate liberated fatty acids
- Complicated because of lack of
stable uniform substrates
- Substrate: olive oil or triolein
- Indicator reaction:
Measures liberated fatty acids released by alkaline titration after 24 hours incubation

Answer 11

Cherry Crandall Method (Titrimetric)

Question 12

Indicator of Cherry Crandall

Answer 12

phenolphthalein (salmon color)

Question 13

indicator of sigma tiet

Answer 13

thymolphthalein

Question 14

Oxidation of glucose-6-phosphate to
6- Phosphogluconate or corresponding
lactone

Answer 14

G6PD

Question 15

Tissue sources:
 Adrenal cortex
 Spleen
 Thymus
 Lymph nodes
 Lactating mammary glands
 RBCs (little activity in normal serum)

Answer 15

G6PD

Question 16

Maintain NADPH in reduced form

Answer 16

G6PD

Question 17

? required to regenerate
sulfhydryl-containing proteins (ex.
glutathione) in its reduced state


Answer 17

NADPH

Question 18

– protects

hemoglobin from oxidizing agents that may be present

Answer 18

Glutathione, reduced form

Question 19

Deficiency is an inherited sex-linked trait & most common in African-Americans

Answer 19

G6PD

Question 20

Only ? has different specimens depending on ↑/↓

Answer 20

G-6-PD

Question 21

2 TYPES OF CHS

Answer 21

Pseudocholinesterase

True Cholinesterase

Question 22

tissue sources type of CHS

Answer 22

 Serum
 Pancreas
 Liver (main)
 Heart
 White matter of CNS

Question 23

type of CHS

Muscle relaxant during surgery

Answer 23

Pseudochs

Question 24

type of CHS
Tissue sources:
 RBCs
 Nerve tissue/cells
 Brain

Answer 24

ACH/ True CHS

Question 25

Hydrolyzes acetylcholine -> choline + acetic acid
For transmission of nerve impulses (acetylcholine is a major
neurotransmitter)

Answer 25

ACH/ True CHS

Question 26

CHS methods

• Measures ↓ in pH resulting from the liberation of acetic acid
• Acid production

Answer 26

Michel Method (Electrometric Method)

Question 27

CHS methods

• Measures the liberation of CO2 from the formation of acetic acid as acetylcholine is hydrolyzed

Answer 27

Manometric Method

Question 28

CHS methods

• Most used
• Uses butylcholine (thiolester) as
  substrate

Answer 28

Ellman Technique (Photometric Enzyme Reaction)

Question 29

Hydrolysis of N-terminal residues from

certain peptides & amides containing free amino groups

Answer 29

Leucine aminopeptidase (LAP)

Question 30

Tx sources

Urine, serum, bile

Answer 30

Leucine aminopeptidase (LAP)

Question 31

Mtd for Leucine aminopeptidase (LAP)

Answer 31

Goldbarg and Rutenberg Method

Question 32

Fluorochrome dyes for Goldbarg and Rutenberg Method

Answer 32

 Acridine orange
 Rhodamine
 FITC (fluorescein isothiocyanate)

Question 33

Reversible conversion of ornithine to

citrulline (synthesis of urea)

Answer 33

Ornithine Carbamoyl Transferase (OCT)

Question 34

OCT tissue source

Answer 34

liver

Question 35

Mtds for OCT (2)

Answer 35

1. Reichard and Reichard Method
   - Isotopic & microdiffusion technique
2. Colorimetric Method

Question 36

Splitting of fructose-1,6-diphosphate to glyceraldehyde-3-phosphate & dihydroxyacetone phosphate

Answer 36

Aldolase

Question 37

Tissue sources:
 Widely distributed in all body cells
 Prominent in skeletal muscles, heart
muscles, liver (most), & RBCs

Answer 37

Aldolase

Question 38

-Important in the breakdown of glucose  lactic acid (glycolytic breakdown)

Answer 38

Aldolase

Question 39

Aldolase

Main tissue source: liver

Answer 39

B

Question 40

Aldolase
Same tissue sources as previous, but
mainly found in the brain
(hippocampus, Purkinje cells)
- Catalyzes breakdown of alcohol

Answer 40

C

Question 41

Aldolase
Found in muscles, RBCs, kidneys,
intestine, liver
- Most in liver
- Reacts with PLD2

Answer 41

A