Relate the following phenomena concepts events etc to one an

Relate the following phenomena, concepts, events, etc. to one another:

1. degeneracy

2. missense mutations

3. nonsense mutations

4. a world with 20 different amino acids

5. a genetic code with triplet code words using four different bases (A, C, G, T)

6. partial loss of function mutations

7. silent mutations

8. a non-overlapping genetic code

9. complete loss of function mutations

NOTE: Relate these items to one another, briefly and succinctly in one or two coherent paragraphs. Be specific; do not use vague generalities. Identify all relationships, not just the most obvious ones. Do not simply define each term and do not write a separate paragraph about each item.

Solution

1. Degeneracy 5. a genetic code with triplet code words using four different bases (A, C, G, Gene refers to a segment of the DNA molecule that codes for a particular amino acid. This gene is coded by four different nucleotides Adenine, Guanine , Cytosine and Thymine. when Dna is transcribed into Mrna Thymine is replaced by Uracil.

The process of protein synthesis is a complex mechanism where The message in the form of codon on the DNA is recognized by the different types of RNAs like the mRNA and t RNA and the information is ultimately used to synthesize a particular amino acid. The amino acids are the building blocks of proteins.

In the Dna molecule each amino acid is denoted by a three lettered sequence of nucleotides called the codon . since it is a three lettered code the code is said to be a triplet codon. As there are only 20 different amino acids and the codon is triplet because of the availability of 4 nucleotides 64 possible codons denoting an amino acid exist in nature which means some of the amino acids have more than one code coding for them the genetic code is said to be degenerate.

Degeneracy of code refers to the coding of an amino acid by more than one codon.

2. missense mutations 6. partial loss of function mutations

missense mutations are a type of mutations where there is a single base pair substitution of different amino acid in the resulting protein which may render it non functional or may have no effect.

ex sickle cell disease in this case replacement of A(GAG) by T(GTG) in the 17 th nucleotide results in the substitution of amino acid glutamine with valine and results in altered haemoglobin structure and causes sickle cell disease.

3. nonsense mutation 9. complete loss of function mutations.

Nonsense mutation is also a type of point mutation wherein a single base is altered but here instead of coding for an different amino acid it results in stop codon signelling the protein synthesis to stop and hence there is complete loss of function.

4. a world with 20 different amino acids 8. a non-overlapping genetic code. different codons for the same amino acid which makes it degenerate but the triplets of the codon are read in successive manner.The genetic code is punctuation less .

for ex if the reading frame is 5\' AUGUCUCCA3\' then

AUG is read for methionine,UCU for serine and CCA for proline thus the reading is successive.