Assignment 4

As powerful as gel electrophoresis is as a technique, changes in the amino acid sequence of a protein can be definitively determined only by analyzing DNA and peptide sequences. The following assignments and questions will help you understand how these techniques can be applied to study protein structure. Work within HemoglobinLab as you answer the questions below.


1 .		Select the Blood Samples view and click on patient Rhonda Emolina. Compare the color of Rhonda's blood with that of the healthy control blood. Is the color of Rhonda's blood consistent with the conditions described in her patient history?

2 .		To determine the cause of Rhonda's anemia (abnormally low number of red blood cells), select the Gel Electrophoresis view. Does Rhonda's hemoglobin migrate differently than the healthy control sample?

3 .		Because the results of this gel electrophoresis experiment are inconclusive in determining whether the cause of her anemia is due to a hemoglobin mutation or another problem such as an iron deficiency, more information about the sequence of Rhonda's hemoglobin protein needs to be considered. Select the Peptide Sequence view and click on the Find Difference button to determine whether Rhonda may contain a mutated version of hemoglobin. Is there a mutation? If so at which position and what amino acid is changed?

4 .		Select the Peptide Sequence view and compare the hemoglobin sequence for each female patient with the control sequence by clicking on the Find Difference button until you identify the female patient with hemoglobin Hammersmith. (Be sure to begin your search by starting at the first amino acid in the protein). Which amino acid is substituted for in this patient?