Genetic Code Reading (Any tips, tricks, would be helpful guys)?!!?

Question

E.g this question:

Use the genetic code at the end of this examination paper to aid in answering the

following questions.

A mutation has occurred in a gene as follows:

Original DNA: AGTTGCACGTGCCTA...

Mutant DNA: AGTTGCACTTGCCTA...

Indicate the original amino acid sequence:

Indicate the new amino acid sequence:

Speculate on the importance of this mutation:

^^^

We are given a genetic code page, it says start here on one of these weird codes, what is the trick to it? how do we figure out answetrs to thse kinda questiosn from it?

Answer 1

Serine Cysteine Threonine Cysteine Leucine

The mutation occurs in the ACG codon. This codes for a threonine. It is changed into ACT. This also codes for a threonine. So it doesn't have any effect. Often the first 2 nucleotides determine the amino acid. So a mutation in the last amino acid is less of a problem (but can still be).

Codons consist of 3 nucleotides. Each code for an amino acid. Mind that you gave the DNA sequence. Codes are read in RNA sequence. Not that big a deal since the only difference is that the T becomes an U. If there is a start codon specified you can have different reading-frames from the point where the start codon begins till a stop codon is reached.

Search the internet for more info since there is a lot on this subject explained in an accessible way.