The Genetic code has 3 features

Degenerate Universal Non overlapping

What is a start codon

At the start of every gene there is a start codon TAC in DNA or AUG in mRNA. This codes for the amino acid methionine. This methionine is later removed from the protein if it is not actually needed for the structure.

At the end of every gene there are 3 bases that do no code for an amino acid and is known as a "stop codon". These stop codons mark the end of a polypeptide chain and cause ribosomes to detach and therefore stop translation.

The feature degenerate has

20 amino acids that the genetic code has to be able to code for. There are four DNA bases and therefore three bases are needed to make enough combinations to code for at least 20 amino acids. This can be proven mathematically.

Examples 1 bases coded for a amino acids

If one base coded for one amino acid this would only allow for 4 amino acids to be coded for. This is insufficient to code for 20 amino acids

Example 2 bases coded for a amino acids

If 2 bases coded for one amino acid this would allow for 16 amino acids to be coded for. This is insufficient to code for 20 amino acids

Example 3 bases coded for amino acids

If 3 bases coded for one amino acid this would allow for 64 amino acids to be coded for

What does degenerate mean

In the genetic code this is when multiple codons can code for the same amino acid.

Why is a degenerate a advantage

This is an advantage as if a point mutation occurs even though the triplet of bases will be different it may still code for the same amino acid and therefore have no effect

Define the genetic code Universal `

The same codon codes for the same amino acids in all organisms this is why the genetic code is described

What is the advantage of universal

This means that genetic engineering is possible

Define what is non overlapping

Each base in a gene is only part of one triplet that codes for one amino acid. Therefore each codon or triplet of bases is read as a discrete unit

Why is non overlapping a advantage

This is an advantage as if a point mutation occurs it will only affect one codon and therefore one amino acid.

These are sections of DNA that do not code for amino acids. Introns are found in eukaryotic DNA but not in prokaryotic DNA. These get removed spliced out of mRNA molecules

Exons are the sections of DNA that do code for amino acids

Differences between genome and proteome

The genome is an organisms complete set of DNA in one cell Proteome is the full range of proteins in one cell The genome should never change The proteome of the cell is constantly changing depending on which proteins are currently needed

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The genetic code

Term	Definition
The Genetic code has 3 features	Degenerate Universal Non overlapping
What is a start codon	At the start of every gene there is a start codon TAC in DNA or AUG in mRNA. This codes for the amino acid methionine. This methionine is later removed from the protein if it is not actually needed for the structure.
What stop codons	At the end of every gene there are 3 bases that do no code for an amino acid and is known as a "stop codon". These stop codons mark the end of a polypeptide chain and cause ribosomes to detach and therefore stop translation.
What are the stop codons	ATT, ATC, ACTT, DNA
The feature degenerate has	20 amino acids that the genetic code has to be able to code for. There are four DNA bases and therefore three bases are needed to make enough combinations to code for at least 20 amino acids. This can be proven mathematically.
Examples 1 bases coded for a amino acids	If one base coded for one amino acid this would only allow for 4 amino acids to be coded for. This is insufficient to code for 20 amino acids
Example 2 bases coded for a amino acids	If 2 bases coded for one amino acid this would allow for 16 amino acids to be coded for. This is insufficient to code for 20 amino acids
Example 3 bases coded for amino acids	If 3 bases coded for one amino acid this would allow for 64 amino acids to be coded for
What does degenerate mean	In the genetic code this is when multiple codons can code for the same amino acid.
Why is a degenerate a advantage	This is an advantage as if a point mutation occurs even though the triplet of bases will be different it may still code for the same amino acid and therefore have no effect
Define the genetic code Universal `	The same codon codes for the same amino acids in all organisms this is why the genetic code is described
What is the advantage of universal	This means that genetic engineering is possible
Define what is non overlapping	Each base in a gene is only part of one triplet that codes for one amino acid. Therefore each codon or triplet of bases is read as a discrete unit
Why is non overlapping a advantage	This is an advantage as if a point mutation occurs it will only affect one codon and therefore one amino acid.
What is a intron	These are sections of DNA that do not code for amino acids. Introns are found in eukaryotic DNA but not in prokaryotic DNA. These get removed spliced out of mRNA molecules
What are exons	Exons are the sections of DNA that do code for amino acids
Differences between genome and proteome	The genome is an organisms complete set of DNA in one cell Proteome is the full range of proteins in one cell The genome should never change The proteome of the cell is constantly changing depending on which proteins are currently needed

Created by: yHya

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