Process of Protein Synthesis – transcription

Transcription – DNA base sequence to mRNA base sequence
• The ‘code’ for the protein is carried by one of the DNA strands in the gene.
• An enzyme separates the two DNA strands at the gene locus exposing the gene sequence.
• A complementary copy - mRNA - is made of the gene sequence –

• New nucleotides form a complementary RNA strand
• Using the DNA gene sequence strand as a ‘master’
• The enzyme RNA polymerase links the new nucleotides forming mRNA.

• Uracil (U) is the complementary base to adenine in RNA, thymine (T) is not found in RNA.
• The complementary RNA copy is called messenger RNA (mRNA).
• The mRNA separates from the DNA strand and passes from the nucleus to the cytoplasm.