Question

To understand how electrophoresis might work we will start with a simple model. We will ignore the gel and assume that the only force acting on the DNA segments is the electric force due to a constant electric field.

Starting with a free body diagram, produce an equation that describes how the electrostatic force acts on DNA segments of different sizes. Use Newton’s 2nd law to decide how this force would affect the motion of different-sized segments of DNA. Does this explain how electrophoresis separates DNA segments by size?

Answer 1

m = mass

a = acceleration

using newtons second law , force equation is given as

F_e = ma

a = F_e /m

the smaller mass segments will faster as compared to larger mass segments Since acceleration is inversly related to the mass