1st Nov '25

Transcribing DNA and Polypeptide Synthesis

Proteins are formed by in the of a cell. Ribosomes are a type of which are made up of proteins and RNA. RNA is the same as DNA except that is usually only a single strand, and uses Uracil as a base rather than Thymine. The RNA in a ribosome is called RNA (rRNA).

DNA is found in the of the cell, but the DNA molecule is too big to fit through the pores of the and so can not get into the . There has to be a messenger molecule, which we called (mRNA).

The enzyme called RNA polymerase is able to the DNA strands. The enzyme moves along the unzipped DNA and makes use of free (nucleotides) found in the nucleus to make the strand of RNA.

The strand of mRNA pass through pores in the nucleus wall, into where synthesise polypeptide (proteins).

Each triplet of bases is known as a codon, and translates into (is the code for) a specific amino acid. RNA (tRNA) which has already attached itself to amino acids, pairs up with the messenger RNA. The amino acids link together to form the desired .