B. 1) Electrophoresis

Question 1

charged molecules moving through a matrix in an electric field will do what

Answer 1

move towards electrode with opposite charge

Question 2

how is the rate of movement of molecules determined

Answer 2

by charged, size and shape. eg, movement of longer molecules slowed by friction

Question 3

common use for electrophoresis

Answer 3

to determine the approx size of fragments of DNA and the size and subunit composition of proteins. the size can be determined by comparison of molecules of known molecular weight

Question 4

DNA fragments, what ingredients are used

Answer 4

matrix used is made from agarose, a carbohydrate polymer isolated from algae. it is boiled and then cooled to form a gel. samples are added to wells formed at one end of gel

Question 5

how will the DNA move

Answer 5

DNA -ve charge therefore movement through gel based on size

Question 6

proteins, what ingredients are used

Answer 6

matrix made by the polymerization of polyacrylamide. a reducing agent like dithiothreitol (DTT) may be used to break disuphide bonds. and SDS-PAGE

Question 7

what does SDS-PAGE stand for

Answer 7

sodium dodecyl sulfate polyacrylamide gel electrophoresis

Question 8

what is SDS

Answer 8

-ively charged detergent. SDS denatures and coats proteins. combo of DDT and SDS denatures proteins, separates subunits and give them a uniform charge. movement of polypeptides through gel based on size