A molecule of DNA consists of 2 chains of nucleotides, coiled around each other to form the familiar double helix.
Each DNA nucleotide contains one of 4 bases: (A)denine, (G)uanine, (C)ytosine, (T)hymine. Each base is paired with it's complementary base on the opposite chain:
Adenine with Thymine (AT) and Guanine with Cytosine (GC).
Genetic words are a 3 base sequence that specifies a particular amino acid. There are 64 possible combinations of these 4 bases in the 3-base genetic words:
(4 x 4 x 4 x 4 = 64).
61 of these combinations are used to code the 20 amino acids.
The other 3 combinations are stop sequences, used in synthesis.
Depends. There are three types of point mutations (changes affecting just one nucleic base pair):
Substitution - the wrong nucleic acid is present. Most of these are silent, but they can result in the wrong amino acid being coded for (Sickle Cell is one of these). In a worst case, they result in the stop codon being found in the middle of a sequence so the protein is truncated.
Deletion - one nucleic acid is removed. These are bad, and cause a frame-shift. The protein is most likely completely changed.
Insertion - an extra nucleic acid is inserted. Also a frame-shift, see above.
Other larger mutations can have similar effects.
Proteins are complex molecules. Each type of protein has a unique three-dimensional shape determined by how the protein folds up. If it does not fold up into the correct shape, it cannot carry out its function in the cell. A protein is held in its shape by bonds formed between amino acids, which are spaced out along the protein molecule. If the wrong amino acid is present, the bond cannot be formed and so the protein cannot take up its correct shape and carry out its function. For example, the disease sickle cell anemia is caused by a single incorrect amino acid in the hemoglobin molecule - a mistake that can be fatal!
either it doesn't change the protein or it changes the protein's shape
Yes it would. It would change the sequence of the codon which will attach to another amino acid
The sequence of nucleotides in DNA molecule is equivalent and is closely related to an amino acid sequence in the protein molecule. If for any reason the sequence of DNA nucleotides changes it will be reflected in amino acid sequence in the protein. Moreover, the correct sequence of amino acid in the protein will form the correct three-dimensional structure, or tertiary structure, that will confer the biological activity to protein. If a wrong amino acid is translated from a mutated gene in the DNA could change the spatial structure of the protein and therefore modify or erase its biological function.
The amino acid sequence is shifted, and this kind of mutation is called a frame shift mutation. All of the amino acid sequence after the mutation will be changed, which will cause a change in shape of the protein, which will then probably result in a nonfunctional protein, since the shape of a protein determines its function.
a change in the sequence of amino acids. -P
mutation is a permanent change in the DNA sequence of a gene and can alter the amino acid sequence of the protein encoded by the gene..
Nonsense mutation
If the point mutation does not change the protein to be translated in the 3-letter sequence, then it will have no effect on the gene's function.
It could change the type of protein that would be produced hence change the structure and function of that protein.
The sequence of nucleotides in DNA molecule is equivalent and is closely related to an amino acid sequence in the protein molecule. If for any reason the sequence of DNA nucleotides changes it will be reflected in amino acid sequence in the protein. Moreover, the correct sequence of amino acid in the protein will form the correct three-dimensional structure, or tertiary structure, that will confer the biological activity to protein. If a wrong amino acid is translated from a mutated gene in the DNA could change the spatial structure of the protein and therefore modify or erase its biological function.
It could change the type of protein that would be produced hence change the structure and function of that protein.
The amino acid sequence is shifted, and this kind of mutation is called a frame shift mutation. All of the amino acid sequence after the mutation will be changed, which will cause a change in shape of the protein, which will then probably result in a nonfunctional protein, since the shape of a protein determines its function.
dna in a cell needs protein and chromosomes.
dna in a cell needs protein and chromosomes.
a change in the sequence of amino acids. -P
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.
dna in a cell needs protein and chromosomes.
dna in a cell needs protein and chromosomes.
dna in a cell needs protein and chromosomes.