Map pling The following statements describe SDS-PAGE, a method used to separate
ID: 875449 • Letter: M
Question
Map pling The following statements describe SDS-PAGE, a method used to separate proteins. Some of the statements are correct, and some of them are incorrect. Select all the correct statements. Sodium dodecyl sulfate denatures the proteins, resulting in protein separation by charge only. in SDS-PAGE, proteins migrate toward the positive electrode. SDS-PAGE uses an agarose gel to separate proteins. Sodium dodecyl sulfate denatures proteins, resulting in proteins that are the same shape. (Assume beta-mercaptoethanol is also present to reduce disulfide bonds.) Smaller proteins migrate farther than larger proteins. in SDS-PAGE, the more negatively charged proteins elute first from the column. previous Give up R View salulinn Check Answer Next ExitExplanation / Answer
SDS (sodium dodecyl sulfate) is a detergent (soap) that can dissolve hydrophobic molecules but also has a negative charge (sulfATE) attached to it. Therefore, if a cell is incubated with SDS, the membranes will be dissolved, all the proteins will be soluablized by the detergent, plus all the proteins will be covered with many negative charges.
The end result has two important features: 1) all proteins retain only their primary structure and 2) all proteins have a large negative charge which means they will all migrate towards the positve pole when placed in an electric field.
Proteins are separated by charge in agarose because the pores of the gel are too large to sieve proteins.
Since we are trying to separate many different protein molecules of different shapes and sizes, we first want to denatured so that the proteins no longer have any secondary, tertiary or quaternary structure (i.e. we want them to retain only their primary amino acid structure).
proteins with net negative charge bind to column (anions are negative); proteins with net positive charge do not bind, and therefore elute first.
OPTION A,B,C,D,E