Please help, anyone!
There's 3 types of gene mutation: substitution, deletion, and insertion, right? So what are '2 kinds of gene mutation that causes the protein to be not formed'??
I mean, gene mutations may cause non functional proteins, but that's not the same as "no protein formed" right??
Please help!
Yes, you are correct that gene mutations can lead to non-functional proteins. However, there are indeed two specific kinds of gene mutations that can result in no protein being formed at all. These two types of mutations are known as frameshift mutations and nonsense mutations.
1. Frameshift mutation: This type of mutation occurs when one or more nucleotides (the building blocks of DNA or RNA) are inserted or deleted from the DNA sequence. As a result, the reading frame of the sequence is shifted, altering the way the genetic code is read during protein synthesis. Frameshift mutations can lead to premature termination of protein synthesis, which prevents the formation of a functional protein.
2. Nonsense mutation: A nonsense mutation is a specific type of point mutation where a nucleotide substitution causes a premature stop codon to be inserted into the DNA sequence. A stop codon normally signals the termination of protein synthesis. When a nonsense mutation introduces a premature stop codon, it prematurely ends the translation process, preventing the formation of a complete and functional protein.
In both cases, the mutations disrupt the normal reading frame or introduce premature termination signals, thereby preventing the proper formation of a functional protein.
You are correct that gene mutations can lead to non-functional proteins, but there are indeed specific kinds of gene mutations that can prevent the formation of a protein altogether. Here are two types of mutations that can cause the absence of a protein:
1. Nonsense mutation: This type of mutation involves a change in the DNA sequence that results in the premature termination of protein synthesis. Normally, there are specific sequences called stop codons that signal the end of protein synthesis. However, a nonsense mutation introduces a premature stop codon, causing the protein to be cut short and preventing its formation.
To identify whether a mutation is a nonsense mutation, you can analyze the DNA sequence and look for any changes that introduce a stop codon within the coding region of the gene.
2. Frameshift mutation: A frameshift mutation occurs when nucleotides (the building blocks of DNA) are either inserted or deleted in the DNA sequence, leading to a shift in the reading frame of the gene. As a result, the subsequent codons are no longer correctly read, leading to a completely different and usually non-functional protein being produced. In some cases, frameshift mutations can cause premature stop codons as well, resulting in the absence of a functional protein.
To detect a frameshift mutation, you would need to sequence the DNA and compare it to a reference or normal DNA sequence. Look for any insertions or deletions of nucleotides that are not in multiples of three, as this indicates a frameshift mutation.
Remember, these are just two examples of mutations that can cause the absence of a protein. There can be other types of mutations that result in similar outcomes, but understanding nonsense and frameshift mutations is a good starting point.