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Why does a base substitution mutation in a gene not always result in a different protein?
Wiki User
∙ 11y ago
Substitution mutations can be silent mutations, meaning that although one of the bases has changed, the codon still codes for the same amino acid.
For example - if the original DNA was changed from AAA to AAG, the codon would change from UUU to UUC.
Both UUU and UUC code for the amino acid phenylalanine - so the resulting protein would be exactly the same. The mutation is therefore called 'silent' because it has no affect.
Wiki User
∙ 11y ago
Wiki User
∙ 11y agoThe answer can vary but the base substitution mutation only effects the base sequence of a certain DNA molecule.
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Which type of mutation results in abnormal acid sequence?
A point mutation causes a change in the amino acid sequence creating a new type of protein. The mutations are categorized functionally as nonsense, missense and silent mutations.
What type of mutation is the most significant effect on protein synthesis?
Mutations change the order in which the organic bases are in your DNA. These bases code for proteins, and if they change, so the code changes. A change in the code can mean a different protein is made or that proteins are not made at all. The way it could stop proteins from being made is that the change could create a Stop Codon, which stops mRNA from being translated (which would then be transcribed into proteins). If it forms a Start Codon, then the wrong section of DNA could be translated and the wrong proteins be synthesised. There is not always a change in to proteins synthesised, as for each amino acid in a protein there is more than one code. A mutation could change the code for a protein into a different code, but for the same protein. In such a case there would be no change.
If a mutation happens within a gene how could this alter the protein that is made by the gene?
DNA codes forproteins. So, if the DNA is mutated, it directly affects the protein. Two examples of mutations are:A point mutation. In this situation, onebase pair(A, T, C, or G) is replaced with a different, incorrect one. When this happens and the DNA is read in order to synthesize a protein, this incorrect base pair can lead to the DNA codon (set of 3 base pairs) that codes for a different base pair than it should have. This causes the protein to have one incorrect amino acid in it. Also, this mutation does not always mutate the protein because some codons code for the same amino acid.A frame shift mutation. This type is much worse. In this case, a base pair is just inserted in to theDNA sequence. When this happens, the entire sequence following it is essentially pushed over one spot. Then, each set of 3 base pairs that would code for an amino acid is shifted so that, instead, you would have something like 2 base pairs and 1 base pair from the codon next to it. This causes every single codon to mutate, which essentially leads to every amino acid being different and therefore, the entire protein being different.I hope that made sense. Diagrams help.
What is the result if mutations occur during meiosis?
The offspring of the organism will have a mutation.
A mutation in a gene may not affect an individual's phenotype because?
A mutation in a gene may not always affect an individuals phenotype because the mutation may occur in a non-coding region. This is known as silent mutation.
Which type of mutation results in abnormal acid sequence?
A point mutation causes a change in the amino acid sequence creating a new type of protein. The mutations are categorized functionally as nonsense, missense and silent mutations.
What type of mutation is the most significant effect on protein synthesis?
Mutations change the order in which the organic bases are in your DNA. These bases code for proteins, and if they change, so the code changes. A change in the code can mean a different protein is made or that proteins are not made at all. The way it could stop proteins from being made is that the change could create a Stop Codon, which stops mRNA from being translated (which would then be transcribed into proteins). If it forms a Start Codon, then the wrong section of DNA could be translated and the wrong proteins be synthesised. There is not always a change in to proteins synthesised, as for each amino acid in a protein there is more than one code. A mutation could change the code for a protein into a different code, but for the same protein. In such a case there would be no change.
Why would an insertion or deletion mutation have more effect than a substitution mutation?
Base-pair insertions have a greater effect because they shift the information on the DNA down and change all following information, whereas substitutions may change only one amino acid or have no effect. -The base-pairs code for amino acids in groups of three. If just one base is added in, then this grouping is shifted upstream by one. The incorrect amino acids will be coded for and added to the protein being built. It could possibly stop the protein from being synthesized fully if the change creates a stop codon. This usually hinders the protein from functioning. -Base-pair substitution mutations only affect the codon (set of 3 base pairs) that it actually occurs in. If the mutation is in the first base-pair of the codon then the amino acid will change. If the mutation is in the second or third position of the codon then amino acid may or may not change; this is because amino acids can be coded for by more than one codon, but the first base-pair (and sometimes the second) is usually the same. A substitution can also change a codon to a stop codon. This may keep the amino acid the same, change only one amino acid (which does not always stop the protein from working), or cause the protein to prematurely stop being built.
If a mutation happens within a gene how could this alter the protein that is made by the gene?
DNA codes forproteins. So, if the DNA is mutated, it directly affects the protein. Two examples of mutations are:A point mutation. In this situation, onebase pair(A, T, C, or G) is replaced with a different, incorrect one. When this happens and the DNA is read in order to synthesize a protein, this incorrect base pair can lead to the DNA codon (set of 3 base pairs) that codes for a different base pair than it should have. This causes the protein to have one incorrect amino acid in it. Also, this mutation does not always mutate the protein because some codons code for the same amino acid.A frame shift mutation. This type is much worse. In this case, a base pair is just inserted in to theDNA sequence. When this happens, the entire sequence following it is essentially pushed over one spot. Then, each set of 3 base pairs that would code for an amino acid is shifted so that, instead, you would have something like 2 base pairs and 1 base pair from the codon next to it. This causes every single codon to mutate, which essentially leads to every amino acid being different and therefore, the entire protein being different.I hope that made sense. Diagrams help.
What is the result if mutations occur during meiosis?
The offspring of the organism will have a mutation.
Is A somatic mutation is always transmitted to the offspring?
no
How are point mutations and frame shift mutations different?
Point Mutations always result in [causing] a frame-shift mutation so they are the same.
How can a single letter change in a DNA sequence could lead to a different protein?
Every single genes has multiple functions to perform. This is very complex phenomena, probably. Contributor tried to explain the same, but probably failed in that attempt. Interaction and discussion is needed for the same probably.
A mutation in a gene may not affect an individual's phenotype because?
A mutation in a gene may not always affect an individuals phenotype because the mutation may occur in a non-coding region. This is known as silent mutation.
Do mutations always alter the encoded protein structure and function?
No. Since a mutation in the DNA may not necessarily result in a change to the encoded amino acid in the protein sequence, it is entirely possible. Further, the protein function will likely not change when an amino acid is replaced with one of similar chemical properties. Sometimes it does, sometimes it doesn't. This is the field that molecular evolutionary biologists study.
Will the substitution method always work?
No, it will not.There are some expressions for which no analytical solution exists.
Do all mutations result in malfunctioning proteins?
No (contrary to previous answer to this question) single base pair mutations, which swap out 1 base for another, say from an A to a G can be a "silent mutation" This means that the 3base "codon" that codes for an amino acid will still code for the same AA. AA's have about 3 different codons that will code for it, usually with the difference being in the last base pair. So for examples lets say AAC and AAT both code for Amino acid X, and the mutation causes the C in sequence AAC to change to a T it becomes AAT, and will still code for amino acid X.... no change in protein structure or function.
