PROTEIN SYNTHESIS

PROTEIN SYNTHESIS.

Transcription –

During transcription an RNA copy of a gene is made in the nucleus.

• Hydrogen bonds between the 2 DNA strands in a gene break and the DNA molecule uncoils.
• One of the strands is then used as a template to make mRNA. The template strand is called the antisense strand.
• mRNA is a single polynucleotide
• RNA is an exact reverse copy of the antisense strand except T is replaced with U.
• Free RNA mononucleotides line up along the template strand. Once they have paired up with their complementary bases they form an mRNA molecule.
• The mRNA moves out of the nucleus through a nuclear pore and attaches to a ribosome in the cytoplasm.
• When enough mRNA has been produced the hydrogen bonds reform and the strands coil back into a double helix.

Translation –

Translation occurs at the ribosomes in the…