Biology! (1 Viewer)

[professorayton8]

Hi! how would answer this question inorder to get the full 3marks? How could a mutation in DNA affect polypeptide production

 

[professorayton8]

Help!!

 

[Omed62]

you could technically breat down the question in two parts and say....

Genetic mutations can induce changes in all downstream pathways (protein synthesis = transcription and translation). If a particular nucleotide base is switched with another (i.e. A to T), then the mRNA strand that is formed will be unique. This unique mRNA strand can be converted into a mutant version of the native protein (not necessarily), which has major impacts on the body. For example, a small mutation in a protein can disrupt the optimal energy structure of the protein (as in a hydrophobic residue surrounded by charged amino acids) and cause conformational changes and biocatalytic changes (remember: Form Follows Function and Function Follows Form).

 

[premskies]

Key concepts involved: polypeptides are made as instructed by the DNA base sequence, and a mutation is a permanent change in the sequence of nucleotides on DNA.

A simple flowchart can answer your question, obviously coupled with some description which I have not included.

DNA Sequence --> Transcription of Incorrect Code to mRNA (Cause of Mutation) --> Translation of Incorrect Code of mRNA --> Incorrect Polypeptide Chain is hence produced --> Causes the formation of deformed proteins (enzymes) --> Consequently Cell Activity is Impacted negatively --> Organism may die.

 

[yasminee96]

start off with an "intro" such as: Polypeptide production relies on the usage of the non-coding strand of DNA as a template for the formation of the mRNA required in polypeptide synthesis.

Cause: A change/mutation in the DNA means that the mRNA will copy incorrect information.

Effect: This may lead to a fault in the codons on the mRNA, which further means that the anticodons on the tRNA may be for different amino acids, for example the codon GAA codes for Glutamic acid, however if "G" was substituted with "C", it then codes for arginine.

what does this mean for polypeptide production? : The formation of incorrect amino acids would hence mean that the chain of amino acids formed (the polypeptide) would be in a different sequence than the one required, and thus an alteration of the polypeptide production.

Conclude with a concluding statement starting with signal words such as "hence" "thus" "therefore" : Therefore, as a change/mutation in DNA means an alteration in mRNA and hence the change amino acids formed which will become part of a polypeptide, the production of polypeptides may become flawed due to a mutation, leading to a flawed or incorrect polypeptide produced.

altogether now :L : Polypeptide production relies on the usage of the non-coding strand of DNA as a template for the formation of the mRNA required in polypeptide synthesis. A change/mutation in the DNA means that the mRNA will copy incorrect information. This may lead to a fault in the codons on the mRNA, which further means that the anticodons on the tRNA may be for different amino acids, for example the codon GAA codes for Glutamic acid, however if "G" was substituted with "C", it then codes for arginine. The formation of incorrect amino acids would hence mean that the chain of amino acids formed (the polypeptide) would be in a different sequence than the one required, and thus an alteration of the polypeptide production. Therefore, as a change/mutation in DNA means an alteration in mRNA, and, hence, the change in amino acids formed which will become part of a polypeptide, the production of polypeptides may become flawed due to a mutation, leading to a flawed or incorrect polypeptide produced.

basically same thing as omed's response, however with a little bit more structure - and hopefully clarity .