L13 - electrophoresis

Question 1

what is electrophoresis

Answer 1

migration of ions in an electric field
used for separation of biological molecules

Question 2

equation for electric force (Felectric) of an ion (q) in an electric field (E)

Answer 2

Felectric = qE

Question 3

equation of frictional force of migrating electrophoretic ion

Answer 3

F(friction) = v(rate of migration velocity) x f(frictional coefficient)

Question 4

equation for characteristic velocity

Answer 4

u = v/E =q/f

Question 5

most commonly used electrophoretic gels

Answer 5

polyacrylamide and agarose

Question 6

what is sodium dodecyl sulphate (SDS)

Answer 6

powerful negatively charged detergent, that binds to proteins and unfolds them

Question 7

role of beta-mercaptoethanol

Answer 7

reducing agent that breaks protein s-s linkages

Question 8

what is the isoelectric point of a protein

Answer 8

the pH at which its net charge is zero
(electrophoretic mobility also 0)

Question 9

detection of proteins by immunoblotting

Answer 9

1. perform gel electrophoresis on protein
   blot the proteins from the gel onto nitrocellulose
2. block the unoccupied binding sites on the nitrocellulose with casein
3. incubate with rabbit antibody
4. incubate with goat anti-rabbit antibody
   5.assay linked enzyme with a colorimetric reaction