Tay Sach's disease is a genetic condition that can be caused by mutations in the hexosaminidase gene resulting in an abnormal enzyme - VCE - SSCE Biology - Question 13 - 2009 - Paper 1
Question 13
Tay Sach's disease is a genetic condition that can be caused by mutations in the hexosaminidase gene resulting in an abnormal enzyme.
The table below shows details ... show full transcript
Worked Solution & Example Answer:Tay Sach's disease is a genetic condition that can be caused by mutations in the hexosaminidase gene resulting in an abnormal enzyme - VCE - SSCE Biology - Question 13 - 2009 - Paper 1
Step 1
A. a substitution of G for C at the beginning of codon 7.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This substitution might not result in an abnormal hexosaminidase, as codon 7 is expected to code for glutamine (gln). A change here may not necessarily lead to a change from an amino acid that would significantly affect enzyme function.
Step 2
B. a duplication of ACU at the beginning of codon 4.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
If ACU is duplicated and then translated, the resulting peptide sequence would not match that of the abnormal enzyme, as there wouldn't be a corresponding change in the following codons.
Step 3
C. an insertion of UAC at the beginning of codon 5.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Inserting UAC at the beginning of codon 5 could provide a different amino acid in this position, but it does not match the observed abnormal sequence directly.
Step 4
D. deletion of UCU at the beginning of codon 6.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Deleting UCU at the beginning of codon 6 would result in the normal sequence being modified, leading to a potential match with the abnormal sequence observed, thus making this the most likely reason for the enzyme being abnormal.
