fbpx

πŸ—οΈ The genetic code

 

Having already covered the basics of DNA, let’s turn our attention to the principles which govern what actually happens to DNA and how this results in life being the way it is!

 

The Dogma

DNA is a large molecule made up of variable bases (adenine, thymine, cytosine, guanine). The precise sequence and location of these bases determines what structure a second molecule, mRNA (messenger RNA) has once it’s β€œread” the template DNA. In turn, the sequence and location of mRNA bases determines what amino acids will be chosen in the assembly of a given protein that the original DNA encoded for, once it reaches a ribosome and is constructed by tRNA (transfer RNA).

mRNA

mRNA stands for messenger ribonucleic acid. DNA is deoxyribonucleic acid, and the only difference really is in the sugar in the backbone. A more important difference is that mRNA is single-stranded unlike double-stranded DNA. Additionally, instead of the base thymine, mRNA uses uracil. So while adenine pairs up with thymine in DNA, it pairs up with uracil in mRNA. Knowing that, the mRNA derived from this DNA (looking at the top strand) would be…

πŸ† Read 500+ topics for all 6 UK exam boards πŸ†

πŸ“ Enter now to claim your FREE 3-day trial and find answers to all your revision topicsΒ πŸ“

βœ”οΈ Just Β£3.49/month after that. Cancel anytimeΒ βœ”οΈ

You explain everything so simply!Β πŸ™‚Β -SecretDuck on The Student Room