Describe the tetracycline group of antibiotics. how do these drugs work? what is their target on a bacterial cell? which types of bacteria are they effective against?

Tetracyclines are antibiotics used against a wide range of microorganisms, such as bacteria, chlamydia, rickettsia and some protozoa parasites.
They inhibit synthesis of protein in bacteria by inhibiting the binding of transport RNA and ribosome and are effective against both gram-positive and gram-negative bacteria.