Enzymes

Front 1

an inorganic ion that increases the catalytic activity of an enzyme

Back 1

activator

Front 2

an inorganic non-protein molecule that is necessary for enzymatic activity

Back 2

Cofactor

Front 3

enzyme activity becomes dependent on subsrate concentration when other reaction conditions are held constant

Back 3

First order kinetics

Front 4

Disruption of the tertiary bonds of a protein molecule that alters the folded structure

Back 4

Denature

Front 5

The combination of an enzyme an its appropriate coenzyme that forms the catalytically active enzyme

Back 5

Holoenzyme

Front 6

LDH/LD

Back 6

Lactate dehydrogenase
E.C. 1 (Oxidoreductases)

Front 7

ICD

Back 7

Isocitrate dehydrogenase
E.C. 1 (Oxidoreductases)

Front 8

G-6-PD

Back 8

Glucose-6-phosphate dehydrogenase
E.C. 1

Front 9

GOT/AST

Back 9

Aspartate transaminase (glutamate oxaloacetate transaminanse)
Aspartate aminotransferase
E.C. 2 (transferases)

Front 10

GPT/ALT

Back 10

Alanine transaminase (glutamate pyruvate transaminase)
Alanine aminotransferase
E.C. 2

Front 11

CPK/CK

Back 11

Creatinine phosphokinase
E.C. 2

Front 12

GGTP/GGT

Back 12

Gamma glutamlytransferase
E.C. 2

Front 13

PK

Back 13

Pyruvate kinase
E.C. 2

Front 14

An enzyme must go throught this type of a change in order to break down the subsrate or open the substrate to allow for more addition.

Back 14

Confirmational change

Front 15

Explain the enzyme-substrate complex.

Back 15

-ES must form before S is altered.
-S binds to active site of enzyme
-formation of ES is reversible
-Enzyme undergoes confirmational change to break/add group
-Release of product is the rate-limiting step.

Front 16

Explain rate limiting step

Back 16

if there is a lot of product in the environment the less likely the enzyme will release product once its formed

Front 17

Many reactions are not reversable in..

Back 17

vitro
(the ES complex is the only part that can be reversed)

Front 18

Red-ox reactions

Back 18

Class 1 enzymes
Category: Oxidoreductases/dehydrogenases

Front 19

Transfer of intact group of atoms from one molecule to another

Back 19

Class II enzymes
Category: Transferases

Front 20

Cleavage of bonds with water

Back 20

Class III enzymes
Category: Hydrolases

Front 21

Cleavage of C-C, C-O, or C-N bonds without water

Back 21

Class IV enzymes
Category: Lyases

Front 22

List the two additional classes of enzymes that hold no clinical significance.

Back 22

Class V and VI
Isomerases, Ligases

Front 23

All the oxidoreductases require a this in order for the enzyme to function?

Back 23

Coenzyme

Front 24

In a lactate dehydrogenase (LDH) assay, 10.0L of serum is mixed with 990.0L of buffer, and the conversion of NADH to NAD+ is monitored at 340nm for 20 minutes in a 1.00 cm cuvette. The A after 20 minutes is 0.527. Calculate the LDH concentration in U/L. The molar absorptivity for NADH is 6220 L/cm-1/mol-1

Back 24

c = {(A / T) / ( • 1)} • (Vt / Vs) • 106 mol/mol
c = {(0.527/20.0)/(6220 L/cm-1/mol-1 • 1 cm)} • {(1000L/ 10L) • 106 mol/mol}
c = 424 mol/min-1/L-1
c = 424 U/L

Front 25

Another name for Aspartate aminotransferase (AST)

Back 25

Serum glutamic oxaloacetic transaminase (SGOT)

Front 26

AST is found in the highest concentration where?

Back 26

heart, LIVER

Front 27

All class 2 enzymes require this as a cofactor.

Back 27

pyradoxyl phosphate

Front 28

Explain the reaction for the Reitman-Frankel method of measurment for AST.

Back 28

Oxaloacetate combined with 2,4-dinitrophenylhydrazine yeiling a dinitrophenylzone derivative.

Front 29

What is the wavelength used to measure the endproducts of the Reitman-Frankel and Babson methods of measurment for AST and ALT

Back 29

504nm

Front 30

In the coupled enzyme assay for AST determination, what is used as a catalyst in the second reaction?

Back 30

Malate dehydrogenase

Front 31

Anytime NADH is included in a reaction, the reaction can be classified as what?

Back 31

Multipoint reaction

Front 32

The new ketoacid produced and utilized in ALT determinations.

Back 32

Pyruvate

Front 33

Another name for Alanine aminotransferase.

Back 33

Serum glutamic pyruvic transaminase (SGPT)

Front 34

What is the more liver specific enzyme AST or ALT?

Back 34

ALT

Front 35

What are the functions of GGT?

Back 35

-Regulates protein synthesis
-Transportation of amino acids

Front 36

Out of the following enzymes; which is more likely to be effected by hemolysis?
AST, ALT, GGT, ALP

Back 36

AST due to it being found within red cells.

Front 37

What is the product measured in GGT determinations and at what wavelength?

Back 37

p-nitroanaline @ 415

Front 38

ALP determinations are normally carried out at what pH?

Back 38

9-10

Front 39

You performed an ALP on a patient and the initial result is 550. The sample was heated to 56 for 30 min reassayed and found to be 320. Based on the percent lost what iso-enzyme is it.

Back 39

42% lost
this would indicate and intestinal iso-enzyme

Front 40

What is the loss of activity for the ALP liver isoenzyme?

Back 40

45-75%

Front 41

What is the loss of activity for the ALP bone isoenzyme?

Back 41

>80%

Front 42

What is the loss of activity for the ALP placenta isoenzyme?

Back 42

0-5%

Front 43

Explan the reference ranges for enzymes with an increased tissue specificity.

Back 43

there would be a much narrower rr due to increased specificity.