How Do Fibers Form?
In this activity, students construct models of sickle cell hemoglobin fibers inside red blood cells to illustrate how changes in the structure of a protein can affect cell shape, as described in the short film The Making of the Fittest: Natural Selection in Humans.
Students step through a procedure for constructing paper models of wild type and mutant hemoglobin molecules. They build mutant hemoglobin fibers to show how these cause red blood cells to take on a different two-dimensional shape. Students then answer questions to explain how these changes in protein and cell structure relate to disease symptoms.
Student Learning Targets
- Use models of sickle cell hemoglobin (HbS) and normal adult hemoglobin (HbA) to explain why fibers form in some red blood cells (RBCs).
amino acid, autosome, dominant trait, HbA, HbS, heterozygote, homozygote, malaria, messenger RNA (mRNA), mutation, recessive trait
Allison, Anthony C. “The Discovery of Resistance to Malaria of Sickle-Cell Zygotes.” Mini-Series: Significant Contributions to Biological Chemistry Over the Past 125 Years. Biochemistry and Molecular Biology Education 30, 5 (2002): 279‒287. https://doi.org/10.1002/bmb.2002.494030050108.
HS-LS1-1, HS-LS1-2, HS-LS3-1; SEP2
IST-1.K, IST-1.N, IST-1.O, IST-1.I, SYI-1.A, SYI-1.B, SYI-1.C, SYI-3.C; SP2, SP6
2.4, 2.7, 3.1, 3.4
CC2, CC3; DP3