RNA Structure. Flashcards
What is RNA?
A polymer of a nucleotide formed from a ribose, a nitrogenous base, and a phosphate group. The nitrogenous base is RNA adenine, guanine, cytosine, and uracil.
Compared to the DNA polymer what is different with the RNA polymer?
In comparison to the DNA polymer, the RNA polymer is a relatively short polynucleotide and is single-stranded. RNA also has the base uracil instead of thymine.
What is the function of RNA?
To copy and transfer the genetic code from DNA in the nucleus to the ribosomes. Some RNA is also combined with proteins to make ribosomes.
What are the 3 types of RNA?
mRNA
tRNA
rRNA
What is mRNA?
Messenger RNA is a copy of the gene from DNA. mRNA is created in the nucleus and it then leaves the nucleus to carry a copy of the genetic code of one gene to a ribosome in the cytoplasm.
Why does RNA function like that?
DNA is too large to leave the nucleus and would be at risk of being damaged by enzymes, therefore destroying the genetic code permanently. mRNA is much shorter, because it is only the length of one gene, and can therefore leave the nucleus.
Why is mRNA short-lived?
As it is only needed temporarily to help create a protein, therefore by the time enzymes would break it down it would have already carried out its function. mRNA is single-stranded and every 3 bases in the sequence code for a specific amino acid.
What are the 3 bases called?
They are codons.
What is tRNA?
Only found in the cytoplasm. It is single-stranded but folded in the shape of a cloverleaf. The cloverleaf shaped is helped together by hydrogen bonds.
What is the function of tRNA?
To attach to one of the 20 amino acids and transfer this amino acid to the ribosome to create the polypeptide chain. Specific amino acids attach to specific tRNA molecules and this is determined by the 3 bases found on the tRNA which are complementary to the 3 bases on mRNA.
What are the anti-codons?
Anti codons are found in tRNA and they are complementary to the codons on mRNA.
What is rRNA?
A type of RNA that makes up the bulk of ribosomes.
