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Biology Help! Genes/Mutation

Explain how a gene codes for protein and how a mutation can lead to change in the protein for which the gene codes
Genes are made up of DNA, which is comprised of 4 bases, A T C and G. 3 of these bases on the DNA code for an amino acid. Proteins are made up of many amino acids linked together by peptide bonds.

When there's a mutation In the DNA, the order of bases is changed either by an addition of another base, a subsitiution for a different base or a deletion of a base. This means the sequence of the bases has changed, so the amino acid those 3 bases code for is different. If there's a different sequence of amino acids, a different protein is coded for.

Hope this helps :smile:
Couldn't have put it any better
Original post by Sugarpuffx
Genes are made up of DNA, which is comprised of 4 bases, A T C and G. 3 of these bases on the DNA code for an amino acid. Proteins are made up of many amino acids linked together by peptide bonds.

When there's a mutation In the DNA, the order of bases is changed either by an addition of another base, a subsitiution for a different base or a deletion of a base. This means the sequence of the bases has changed, so the amino acid those 3 bases code for is different. If there's a different sequence of amino acids, a different protein is coded for.

Hope this helps :smile:


Just adding - obviously you don't need this much detail - sorry if I'm wrong

change in an organic nitrogenous base
change triplet code
possible change in a.a. (some a.a. have more than 1 triplet code)
change in amino acid sequence (primary structure)
change in secondary structure (alpha helix, beta pleated sheets)
change in tertiary structure
(change in hydrogen/ionic/disulphide bonds)
change in quaternary globular/fibrous structure

(if enzymes leading to non-functional enzyme))
possible change in shape of active site
active site no longer complementary w/ substrate
no enzyme-substrate complex formed

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Original post by XcitingStuart
Just adding - obviously you don't need this much detail - sorry if I'm wrong

change in an organic nitrogenous base
change triplet code
possible change in a.a. (some a.a. have more than 1 triplet code)
change in amino acid sequence (primary structure)
change in secondary structure (alpha helix, beta pleated sheets)
change in tertiary structure
(change in hydrogen/ionic/disulphide bonds)
change in quaternary globular/fibrous structure

(if enzymes leading to non-functional enzyme))
possible change in shape of active site
active site no longer complementary w/ substrate
no enzyme-substrate complex formed

Posted from TSR Mobile


I agree with everything you say :smile:
I just made an A level answer into a GCSE answer
(edited 9 years ago)
literally all you need in an AS level answer is

change in base sequence
change in amino acid (primary structure)
change in tertiary structure
(change in hydrogen/ionic/disulphide bonds)

Posted from TSR Mobile

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