Why are deletions or insertions of nucleotides likely to be more detrimental than base substitutions?

Question

Why are deletions or insertions of nucleotides likely to be more detrimental than base substitutions?

Answer 1

Most base substitutions have no effect on the function of the encoded protein; many are silent mutations.  Deletions or insertions shift the reading frame, leading to premature termination of protein synthesis and a nonfunctional or aberrant protein.

Answer 2

Insertion or deletion lead to sudden change in the genetic material DNA causing mutation lead to change in the formed protein or enzyme cause a shift in the reading frame (frameshift), both of which can significantly alter the gene product. which is less to occur in the substitution of bases

Answer 3

Frame shift.

Answer 4

An amino acid is coded for by 3 nucleotides, so if you delete or insert one nucleotide you will s***w up the whole genetic code for that protein. In other words, all amino acids in that protein from the deletion/insertion onwards will be affected. But a base substitution just change one nucleotide, so just one amino acid will be affected. And since there are more triplets than amino acids, a base substitution might not even cause a change in the protein at all.

Answer 5

I agree with the answer above. Insertion or deletion that is not a multiple of 3 will cause a "frameshift", which means all the down stream amino acids will be changed. If you recall the codons, there are 3 of them codes for stop, they are "UGA, UAU, UAA". Often times, when a framshift takes place, the protein will end up to short because the early onset of the stop codon. And the protein will most likely be non-functional.

A substitution, on the other hand, can cause many different results. If the sub codes for the same AA, then no change will occur. If the sub codes for a different AA, it could be deviate too much in terms of polarity and cause incorrect folding of the protein. Of course there are also cases when a sub changes a codon to a stop codon, then the protein will be too short to be functional.

So overall, deletion or insertion can be more harmful.

Answer 6

Because DNA (the code) uses 3 bases to code for 1 aminoacid of protein (the functional molecule). So a substitution in DNA will change one aminoacid only and leave the rest of the protein intact, but a deletion or insertion will change the rest of the protein molecule as well.

Answer 7

The basis of the genetic code is sequences of three bases on DNA. Three bases code for one amino acid in polypeptide chains in proteins.

A Base substitution will only alter one of the triplet codes and is called a point mutation.

Deletion or insertion will alter the whole code after the point of the insertion or deletion and is called a frame shift mutation.

This is more likely to be derimental as the genetic code is 'read' incorrectly and results in chains with the incorrect amino acids ie a non functioning protein which may be an essential enzyme or hormone.

Hope this helps!

Answer 8

The sequence is a line of nucleotides, and it is grouped into three nucleotides, and these three choose the amino acid.  (but I guess they aren't physically grouped, since deletions/insertions muck up the whole thing on the after side of the mutation).

If you have a sequence Glutamic Acid-Alanine-Glutamic Acid-Aspartic Acid, the DNA has three nucleotides in a row to define each.  So each sequence of nucleotides makes an amino acid every three nucleotides without these being permanent groups of three but dependent on the ones in front of them to not lose or take any (except multiples of three).  

If it does add or take one or two, or four or five, etc., then each codon (set of three nucleotides) is starting in one and ending in the other, which changes alot of the next amino acids.