Here I have summarised all you need to know about DNA and RNA based on my first year of A-level biology study. It's very useful to look back on to get a refresher and includes everything you need to know based on exam questions and mark schemes that I have come across. This includes information abo...
DNA RNA
DNA consists of 4 nitrogenous bases, Adenine, Thymine, RNA consists of the same nitrogenous bases as DNA except thymine, which is
Guanine, Cytosine which pair via complementary base replaced with uracil, so the base pairs are A+U and C+G.
pairing RNA polymerase is used to join nucleotides via phosphodiester bonds.
DNA helicase breaks H-Bonds between the bases RNA has a ribose sugar
DNA polymerase joins the nucleotides by forming
mRNA production:
phosphodiester bonds
DNA strands separate (h-bonds break)
DNA has a deoxyribose sugar
One strand is used as a template to make the mRNA
DNA in eukaryotic cells VS prokaryotic cells: Bases used are, adenine, uracil, guanine, cytosine
Nucleotide structure is identical RNA polymerase joins nucleotides (phosphodiester bonds)
Nucleotides join via phosphodiester bonds in both cells This forms pre-mRNA which contains introns, which are removed via splicing leaving
Eukaryotic DNA is longer mRNA
Eukaryotic DNA contains (non-coding) introns, whereas
Translation:
Prokaryotic DNA does not.
mRNA associates with a ribosome
Eukaryotic DNA is linear, prokaryotic DNA is circular
tRNA carries amino acids and contains an anticodon to the mRNA codon.
Eukaryotic DNA is associates with proteins (histones);
tRNA will bind to the mRNA one codon after the other, between this, amino acids
prokaryotic DNA is not.
are joined together via peptide bonds which allows the tRNA to move off.
Semi-conservative method: This continues down the whole strand of mRNA until a stop codon is reaches and
the polypeptide chain becomes released from the ribosome.
One strand of DNA is always used as a template, this
Structural differences between mRNA and tRNA:
means that 50% of the new DNA strand will be from the
mRNA compromises of codons, tRNA compromises of anticodons.
old/original strand. This ensures that replication is
mRNA is linear and tRNA is clover leaf shaped.
accurate.
mRNA is longer than tRNA.
DNA compared to mRNA:
DNA is double stranded mRNA is single stranded.
DNA has a deoxyribose sugar, mRNA has a ribose sugar
DNA has thymine, mRNA has uracil.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller emiliakurzepa12. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £8.29. You're not tied to anything after your purchase.
