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GCSE Biology DNA *help*

I was trying to find the definition of a codon on Google and it came up with "A sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule". I thought a codon was just a group of three bases not three nucleotides. . Can someone pls explain this to me?
Thanks
Reply 1
Avatar for 06moca1
06moca1
14
Original post by skits267
I was trying to find the definition of a codon on Google and it came up with "A sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule". I thought a codon was just a group of three bases not three nucleotides. . Can someone pls explain this to me?
Thanks


Nucleotide bases.
A base in DNA is part of a nucleotide, the other parts being the pentose deoxyribose sugar and the phosphate group. Therefore at GCSE you can use both terms pretty much interchangeably. However, as the bases is the only difference in the structure of the nucleotides, that is what ultimately codes for the different amino acids. For example, the codon for the amino acid lycine is AAA.
the base is the A/T/C/G bit, the nucleotides is the base AND the sugar AND the ribose (everything together).
Reply 4
Avatar for skits267
skits267
OP
9
Original post by XxSaruman82xX
A base in DNA is part of a nucleotide, the other parts being the pentose deoxyribose sugar and the phosphate group. Therefore at GCSE you can use both terms pretty much interchangeably. However, as the bases is the only difference in the structure of the nucleotides, that is what ultimately codes for the different amino acids. For example, the codon for the amino acid lycine is AAA.


Ohhh ok so just to recap you can call it a sequence of nucleotides as well because it is the bases that are the only different section of the nucleotide
Original post by skits267
I was trying to find the definition of a codon on Google and it came up with "A sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule". I thought a codon was just a group of three bases not three nucleotides. . Can someone pls explain this to me?
Thanks


A codon's basically 3 bases grouped together, that code for one amino acid. For example, ACG and TAG are codons.
Original post by skits267
Ohhh ok so just to recap you can call it a sequence of nucleotides as well because it is the bases that are the only different section of the nucleotide


Yeah that's absolutely right. Glad I could help!

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