Biology
A gene mutation is a change in one or several bases. A base may be added, deleted, or substituted with another base. This is caused often through the action of damaging chemicals, radiations, or through errors inherent in DNA replication and repair reactions. If a base is added or deleted, frameshift is the result as a different amino acid is coded for. As the sequence of amino acids is altered, a non-functional protein may be produced. However, in some cases, mutations do not affect the amino acid coded for. This is because the mutation may occur in a non-coding region of the DNA. The genetic code is also degenerate as more than one codon may code for a certain amino acid. Finally, the amino acid may be in a non-essential position of the polypeptide, hence its 3 dimensional structure is not significantly altered.
- Suppressor Trnas Have Mutated Anticodons That Read New Codons
KEY TERMS:A suppressor is a second mutation that compensates for or alters the effects of a primary mutation. A nonsense suppressor is a gene coding for a mutant tRNA able to respond to one or more of the termination codons and insert an amino acid at...
- Prokaryotic Genes Are Colinear With Their Proteins
KEY TERMS:A colinear relationship describes the 1:1 representation of a sequence of triplet nucleotides in a sequence of amino acids. KEY CONCEPTS: A prokaryotic gene consists of a continuous length of 3N nucleotides that codes for N amino acids. The...
- The Genetic Code Is Triplet
KEY TERMS:The genetic code is the correspondence between triplets in DNA (or RNA) and amino acids in protein. A codon is a triplet of nucleotides that represents an amino acid or a termination signal. Frameshift mutations arise by deletions or insertions...
- Mutations May Cause Loss-of-function Or Gain-of-function
KEY TERMS:A null mutation completely eliminates the function of a gene. Leaky mutations leave some residual function, for instance when the mutant protein is partially active (in the case of a missense mutation), or when read-through produces a small...
- # 35 The Genetic Code - Protein Synthesis
The genetic code specifies the amino acids that are assembled to make polypeptides. The way that DNA codes for polypeptides is central to our understanding of how cells and organisms function. A polypeptide is coded for...
Biology
Gene mutation
A gene mutation is a change in one or several bases. A base may be added, deleted, or substituted with another base. This is caused often through the action of damaging chemicals, radiations, or through errors inherent in DNA replication and repair reactions. If a base is added or deleted, frameshift is the result as a different amino acid is coded for. As the sequence of amino acids is altered, a non-functional protein may be produced. However, in some cases, mutations do not affect the amino acid coded for. This is because the mutation may occur in a non-coding region of the DNA. The genetic code is also degenerate as more than one codon may code for a certain amino acid. Finally, the amino acid may be in a non-essential position of the polypeptide, hence its 3 dimensional structure is not significantly altered.
- Suppressor Trnas Have Mutated Anticodons That Read New Codons
KEY TERMS:A suppressor is a second mutation that compensates for or alters the effects of a primary mutation. A nonsense suppressor is a gene coding for a mutant tRNA able to respond to one or more of the termination codons and insert an amino acid at...
- Prokaryotic Genes Are Colinear With Their Proteins
KEY TERMS:A colinear relationship describes the 1:1 representation of a sequence of triplet nucleotides in a sequence of amino acids. KEY CONCEPTS: A prokaryotic gene consists of a continuous length of 3N nucleotides that codes for N amino acids. The...
- The Genetic Code Is Triplet
KEY TERMS:The genetic code is the correspondence between triplets in DNA (or RNA) and amino acids in protein. A codon is a triplet of nucleotides that represents an amino acid or a termination signal. Frameshift mutations arise by deletions or insertions...
- Mutations May Cause Loss-of-function Or Gain-of-function
KEY TERMS:A null mutation completely eliminates the function of a gene. Leaky mutations leave some residual function, for instance when the mutant protein is partially active (in the case of a missense mutation), or when read-through produces a small...
- # 35 The Genetic Code - Protein Synthesis
The genetic code specifies the amino acids that are assembled to make polypeptides. The way that DNA codes for polypeptides is central to our understanding of how cells and organisms function. A polypeptide is coded for...