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2. BRAIN MECHANISMS: NEUROBIOLOGY AND NEUROANATOMY

Fig. 2.9 Synthesis of proteins
Portions of DNA in the nucleus of a neuron are encoded into messenger
RNA. Ribosomes in the cell body use messenger RNA to synthesize proteins.

Step 1. Strands of mRNA duplicate portions of the genetic code from DNA
in the nucleus and carry it into the cytoplasm.

DNA
Nucleus
mRNA

Step 2. In the cytoplasm, the strands of mRNA bind to ribosomes.

Ribosome

Step 3. The ribosomes move along the strands of mRNA reading the
genetic code, and create the appropriate chain of amino acids from the
amino acids in the cytoplasm.

mRNA Amino acid

Ribosome

Step 4. The proteins are released into the cytoplasm.

Protein

Source: Reproduced from Pinel, 1990, with permission from the publishers.

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