- Messages
- 10
- Reaction score
- 2
- Points
- 3
Q: describe the way in which the nucleotide sequence codes for the amino acid sequence in a polypeptide
with reference to the nucleotide sequence for HbA (normal) and HbS (sickle cell) alleles of the gene for
the β -haemoglobin polypeptide.
(This is from Syllabus! Could anyone answer this?)
The nucleotide sequence for an amino acid consists of a triplet code. Due to a mutation a different nucleotide sequence can arise.
In this case base substitution occurs where one Thymine from CTT is substituted with Adenine forming CAT. Therefore the amino acid valine forms instead of glutamate. (Allele for HbA contains CTT while allele for HbS contains CAT) Formation of HbS leads to sickle cell anaemia.
Thats as far as i know. Someone else might have a better one.