Sickle cell disease (SCD) is a group of inherited disorders - AQA - A-Level Biology - Question 2 - 2019 - Paper 2
Question 2
Sickle cell disease (SCD) is a group of inherited disorders. People with SCD have sickle-shaped red blood cells. A single base substitution mutation can cause one ty... show full transcript
Worked Solution & Example Answer:Sickle cell disease (SCD) is a group of inherited disorders - AQA - A-Level Biology - Question 2 - 2019 - Paper 2
Step 1
Change in (sequence of) amino acids (primary structure)
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Answer
The single base substitution in the DNA sequence results in a change in the amino acid sequence of the beta polypeptide chain. This alteration in the primary structure can lead to the incorporation of a different amino acid into the protein.
Step 2
Change in hydrogen/ionic/disulfide bonds
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Answer
The change in the amino acid sequence may affect interactions such as hydrogen bonds, ionic bonds, or disulfide bridges. This results in a different folding pattern of the protein.
Step 3
Alters tertiary/3° structure
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Answer
Consequently, the overall three-dimensional (tertiary) structure of the hemoglobin molecule is altered, affecting its function and stability, leading to the sickling of the red blood cells.
