Consider the following mutations and, for each, explain whether you expect it to
ID: 44723 • Letter: C
Question
Consider the following mutations and, for each, explain whether you expect it to be
a) potentially promoting cancer
b) dominant or recessive
1) A mutation that destroys the active site of an enzyme necessary to promote cell cycle
2) A very premature STOP codon in a gene encoding a protein involved in the excision-repair mechanism
3) A point mutation that renders constitutively active one of the signaling proteins in the Ras pathway
4) A null mutation in a gene encoding an apoptotic (apoptosis-promoting) protein.
Explanation / Answer
Answer:
1) A mutation that destroys the active site of an enzyme necessary to promote cell cycle : If the active site of the enzyme is destroyed by the mutation, the cell cycle will not continue and it is recessive.
2)A very premature STOP codon in a gene encoding a protein involved in the excision-repair mechanism: if repair of the gene is not done this may lead to malfunctioning of the protein leading to recessive.
3)A point mutation that renders constitutively active one of the signaling proteins in the Ras pathway: an excessive signaling can be observed, due to this, cancer can be formed.
4)A null mutation in a gene encoding an apoptotic (apoptosis-promoting) protein: do not code for enzyme of nonfunctional, so cell death will not occur leading to cancer.