protein synthesis and rna

rna context in bio moles

what is the function of mRNA?

messenger RNA - transfers genetic info between nucleus and ribosomes

what is the function of rRNA?

ribosomal RNA - acts as a component of ribosomes

what is the function of tRNA?

transfer RNA - needed to bring amino acids to the ribosomes

what is pre-mRNA?

• long, single stranded molecule of RNA transcribed by a gene

• contains introns

what is splicing?

• process of removing introns from pre-mRNA to form mRNA

• this means than the mRNA is shorter so it can leave the nucleus through the nuclear pores and reach the ribosomes

describe the process of transcription:

• RNA polymerase binds to and moves along DNA double helix, separating DNA strands by breaking H bonds between strands

• non-coding strand acts as template

• RNA nucleotides join to complementary bases by RNA polymerase

• RNA polymerase catalyses formation of phosphodiester bonds between adjacent RNA nucleotides

• ends when RNA polymerase reaches a stop codon, detaches from DNA and terminates transcription

• mRNA displaced by DNA molecules becoming rejoined

• mRNA leaves through nuclear pore

what is tRNA?

single strand of RNA that carries a specific amino acid to the ribosome

describe the process of translation:

• mRNA strand leaves nucleus via nuclear pore and is w/in cytoplasm

• ribosome attaches to mRNA strand

• tRNA molecule attaches to mRNA strand at anticodon, which is complementary to the codon

• 2nd tRNA molecule binds

• amino acid complementary to codon

• 3rd tRNA molecule binds and peptide bond formed between 1st and 2nd amino acid, facilitated by ribosome

• 1st tRNA molecule moves away and ribosome moves along

• repeats until stop codon reached, causing translation to terminate → polypeptide chain

what is the anticodon?

the part of the tRNA complementary to the codon

what is the function of the sections of dsRNA in the tRNA molecule?

to form the shape of the tRNA molecule