Explain why the one-gene:one-enzyme concept is not considered totally accurate today.
Ch. 14 - Translation and Proteins

Chapter 14, Problem 20
Contrast the contributions of Pauling and Ingram to our understanding of the genetic basis for sickle-cell anemia.
Verified step by step guidance1
Understand the context: Sickle-cell anemia is a genetic disorder caused by a mutation in the hemoglobin gene, leading to abnormal hemoglobin structure and function.
Explore Linus Pauling's contribution: Pauling was the first to demonstrate that sickle-cell anemia is a "molecular disease" by showing that the hemoglobin in sickle-cell patients had a different structure compared to normal hemoglobin. He used electrophoresis to separate the hemoglobin molecules based on their charge.
Examine Vernon Ingram's contribution: Ingram furthered the understanding by identifying the specific genetic mutation responsible for sickle-cell anemia. He used peptide mapping and sequencing to show that a single amino acid substitution (glutamic acid to valine) in the beta chain of hemoglobin was the cause of the disease.
Compare their contributions: Pauling's work laid the foundation by establishing the concept of a molecular basis for genetic diseases, while Ingram pinpointed the exact molecular change, providing a more detailed understanding of the genetic mutation involved.
Reflect on the impact: Together, their work highlighted the importance of molecular biology in understanding genetic disorders and paved the way for future research into genetic mutations and their effects on protein function.

Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Sickle-Cell Anemia
Sickle-cell anemia is a genetic blood disorder caused by a mutation in the hemoglobin gene, leading to the production of abnormal hemoglobin known as hemoglobin S. This mutation results in the distortion of red blood cells into a sickle shape, which can cause blockages in blood vessels, pain, and various complications. Understanding this condition is crucial for appreciating the genetic contributions made by researchers like Pauling and Ingram.
Recommended video:
Guided course
Cell-cell interactions
Linus Pauling's Contribution
Linus Pauling was a pioneering chemist who, in the 1940s, used electrophoresis to demonstrate that sickle-cell anemia was associated with a specific molecular change in hemoglobin. He proposed that the disease was caused by a single amino acid substitution in the hemoglobin protein, marking one of the first instances of linking a genetic mutation to a specific disease phenotype. This work laid the groundwork for molecular genetics and the understanding of genetic diseases.
Recommended video:
Guided course
Analyzing Trait Variance
Harold Ingram's Contribution
Harold Ingram expanded on Pauling's findings by conducting further studies that confirmed the relationship between the sickle-cell trait and the specific mutation in the beta-globin gene. Ingram's research provided a clearer understanding of the genetic basis of sickle-cell anemia, demonstrating how the mutation leads to the production of abnormal hemoglobin. His work was instrumental in establishing the field of molecular genetics and the concept of genetic disease inheritance.
Recommended video:
Guided course
Analyzing Trait Variance
Related Practice
Textbook Question
1121
views
Textbook Question
Why is an alteration of electrophoretic mobility interpreted as a change in the primary structure of the protein under study?
559
views
Textbook Question
Using sickle-cell anemia as an example, describe what is meant by a molecular or genetic disease. What are the similarities and dissimilarities between this type of a disorder and a disease caused by an invading microorganism?
745
views
Textbook Question
Hemoglobins from two individuals are compared by electrophoresis and by fingerprinting. Electrophoresis reveals no difference in migration, but fingerprinting shows an amino acid difference. How is this possible?
543
views
Textbook Question
HbS results in anemia and resistance to malaria, whereas in those with HbA, the parasite Plasmodium falciparum is able to invade red blood cells and cause malaria. Predict whether those with HbC are likely to be anemic and whether they would be resistant to malaria.
801
views
Textbook Question
Several amino acid substitutions in the α and β chains of human hemoglobin are shown in the following table.
Using the code table, determine how many of them can occur as a result of a single-nucleotide change.
759
views
