Protein Synthesis


Protein synthesis is the process by which genetic information from the
DNA stored in the nucleus is transferred to the ribosomes where it is used to
arrange amino acids into proteins.
The DNA molecule in the nucleus is unzipped by an enzyme called
polymerase. From one of these single strands of a DNA molecule, a mRNA molecule
is built. This is accomplished by an enzyme which travels along a portion of DNA
between two exons and attaches the opposing base pairs to the backbone of the
mRNA (a structure composed of phosphates and ribose). The nitrogen bases of this
new molecule are identical to that of the opposite side of the original DNA
molecule except that the thymine has been replaced with uracil. The formation of
this molecule allows for the construction of proteins in the ribosome without
risking the DNA in the cytoplasm.
The mRNA travels through the cell to a ribosome. Here tRNA which contain
the appropriate anti-codon collect the amino acids coded for in the mRNA. Each
amino acid is connected to the next amino acid. The mRNA thus transverses the
ribosome with each three nitrogen base condon selecting an amino acid. This
continues until the ribosome encounters a stop condon. When this happens the
amino acid chain is released from the tRNA and is a protein.
This process allows for the genetic information stored in the DNA to be
expressed in the physical and functional makeup of the cell.

Category: Science