Polyacrylamide gel electrophoresis (PAGE) separates proteins based on differences in which of the following? Please select all that apply.

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Quizplus · Accepted Answer

Unlike DNA gel electrophoresis, which separates molecules only on their size, PAGE separates by size and by charge. In DNA molecules, the charge is on the phosphates in the sugar-phosphate backbone and therefore does not differ between different DNA sequences. In proteins, the charge is carried by the amino acid side chains, which vary with the specific amino acid residues. Hence, different protein molecules may have both a different size and a different charge. Modified PAGE methods exist, including a method where charges are equalized and separation is only by size. GC% relates to DNA and does not affect separation of proteins.

Polyacrylamide Gel Electrophoresis (PAGE) Separates Proteins Based on Differences in Which