8 structure of RNA

what’s rna?

a polymer of a nucleotide formed of a ribose, a nitrogenous base, and a phosphate group

what are the nitrogenous bases of rna?

• adenine

• guanine

• cytosine

• uracil

compared to dna, is the rna polymer shorter of longer,

a relatively short polynucleotide chain which is also single stranded

what’s 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 create ribosomes

what are the three types of rna?

• nRNA

• tRNA

• rRNA

what’s mRNA?

a copy of a gene from DNA

what does the ‘m’ in mRNA stand for?

messenger

where’s mRNA created?

in the nucleus

what’s the function of mRNA?

to leave the nucleus and carry a copy of the genetic code of one gene to a ribosome and cytoplasm

what would happen if DNA were to leave the nucleus?

would be at risk of being damaged by enzymes, destroying the genetic code permanently as it’s too large to leave the nucleus

why is mRNA much shorter?

it’s only the length of one gene and can therefore leave the nucleus

why is mRNA short lived?

it’s only temporarily needed to help create a protein, by the time any enzymes could break it down, it would have already carried out its function

is mRNA single stranded?

yes, every 3 bases in the sequence code for a specific amino acid, these three bases are called codons

what does the ‘t’ in tRNA stand for?

transfer

where’s tRNA found?

only in the cytoplasm

what’s the structure of tRNA?

single stranded but folded to create a shape that looks like a cloverleaf. this clover leaf shape is held together by hydrogen bonds

what’s the function of tRNA?

to attach to one of the 20 amino acids and transfer this amino acid to the ribosome to create a polypeptide chain

specific amino acids attach to specific tRNA molecules, how is this determined?

by 3 bases found on the tRNA which are complimentary to the 3 bases on mRNA. these are called anticodon as they’re complimentary to the codon on mRNA

what does the ‘r’ in rRNA stand for?

ribosomal

what’s the function of the rRNA?

makes up the bulk of ribosomes

what does rRNA combine with?

proteins to make ribosomes

what’s the difference between DNA and RNA monomers?

• DNA contains base thymine, RNA contains uracil

• DNA contains the pentose sugar deoxyribose, RNA contains the pentose sugar ribose

what’s the difference between DNA and RNA polymers?

• DNA is much larger because it contains around 23000 genes (the entire genome), RNA is much shorter as it is only the length of one gene

• DNA is double stranded, RNA is single stranded