Question

Doxyxycline is a tetracycline antibiotic used to fight disease in humans, but can negatively affect the health of eukaryotic cells. Using evolutionary arguments to support your answer, why is doxycyline able to impact mitochondrial activity and is not able to bind to eukaryotic small ribosomal subunits? What central dogma of biology does doxycyline work to inhibit within bacterial cells?

Answer 1

Doxycycline has ability to bind with the smaller subunit of ribosome of prokaryotic cells, that is 30S subunit. This drug block the A site of the ribosome, where charged tRNA will bind.

Ribosome is also called as protein factories. The process of translation is carried by this organelle. RNA information is converted into protein chain. Central dogma of protein synthesis is blocked by this drug.

Prokaryotic cells smaller subunit of ribosome is 30S type, while in eukaryotic cells the smaller subunit is 40S type. Because of which this drug do not target the eukaryotic ribosome small subunit.

Eukaryotic cells have mitochondria. These mitochondria are Prokaryotic in origin as per the endosymbiont theory of evolution. Mitochondria contain 30S type of smaller subunit. This subunit is also inhibited by this drug.

Mitochondria is power house of cell. It produces energy in the form of ATP. If mitochondria is adversely affected by this drug then eukaryotic cell is also get damaged.