Question

) Explain the main steps that occur during translation, from the transport of mRNA, from the nucleus to the cytoplasm, to the synthesis of a new polypeptide. Include in your answer the role of: nuclear pores, ribosomes and rRNAs, codons and tRNAs.

Answer 1

DNA has the code as the sequence for the proteins. This is transcribed into mRNA sequence. This molecule passes through the nuclear pore into the cytoplasm. There the ribosomes attach to the RNA chain. tRNA molecules have the amino acids attached to it and bearing the complementary read for the Nucleotide. The tRNA that bears the complementary code against the mRNA attaches to the ribosome and keep on adding to the growing aminoacid chain. The code reading and matching is done in set of three, meaning three nucleotides are read at a time. This set of three is called a codon. Hence mRNA has codons and the tRNA bears an anticodon region which must bear complementarity to the codon. Each codon codes for a specific amino acid. There are 64 codons in all, but only 20 amino acids so there is a degeneracy there.