Chapter 5, Problem 24CQ

(a)

Summary Introduction

To draw: The plot for the result of gel filtration of a mixture containing human cytochrome c and bacteriophage T7 RNA polymerase with absorbance of 280nm versus elution volume.

Concept introduction: Gel filtration is a technique used for the separation of molecules on the basis of their molecular size. In this technique, molecules move through the pores of beads, diffusing into the beads with greater or lesser degrees of interaction. Absorbance is the measurement of the amount of light that a substance absorbs at a particular wavelength of light. The UV absorption of proteins is used to identify the spectra of microscopic samples. The spectra of the protein sample are used to identify the protein concentration and relative amount of protein.

(b)

Summary Introduction

To draw: The results of SDS-PAGE of the protein human cytochrome c and bacteriophage T7 RNA polymerase showing the direction of migration by identifying each band in the gel.

Concept introduction: Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analyzes the protein mixture on the basis of size. Proteins that have higher and lower molecular masses run slowly and fast in the gel under the effect of an electric field, respectively.