Gfilui

After searching "do antibiotics impact the immune system" I found out that antibiotics target prokaryotic cells. It all made a lot of sense thinking about all those yoghurt recommendations you get after taking antibiotics : the collateral damage is on the prokaryotic cells that live with us but are not "us" as such.
Except I remembered human red blood cells don't have nuclei, so where's my confusion ?

(I'm only a biology enthusiast)

When differences between prokaryotes and eukaryotes are taught in an introductory biology course, a generic prokaryotic cell and a generic eukaryotic cell are typically compared. Cells in a complex multicellular organism, like a human, are quite diverse. Human red blood cells are one example of a highly specialized cell with a mature form that is quite different from the typical eukaryotic cell. Keratinocytes in the epidermis are another example (see Ross Histology, Ch. 15). In both cases, these cells produce large amounts of a single protein, eventually, at their most mature stage, stopping protein synthesis, extruding their nuclei and most other organelles.

The absence of a nucleus or other organelles, however, does not necessarily make either of these cells more susceptible to antibacterial antibiotics. Antibiotics are targeted toward things that bacteria have (positive differences), rather than the absence of typical eukaryotic structures. Almost all antibacterial antibiotics have one of three targets (see Goodman and Gilman Chs. 48, 52-55):

• The bacterial cell wall or membrane




• protein synthetic machinery




• specialized metabolites required by bacteria

There is (almost) no overlap between these structures in bacteria and structures in any of the diverse array of human cells. The one partial exception is a similarity between the mitochondrial and bacterial ribosome, that may, for example, be responsible for some of the toxicity of chloramphenicol (G&G Ch. 55).

No. Prokayotic cells are full organisms with their own DNA, red blood cells are not.

No, they are matured (broken) reticulocytes without the net structure and ribosomal DNA, which themselves are matured (broken) normoblasts that have lost their nucleus.

So basically they're the left over plasma membrane of a once-alive eukaryote cell, now filled with mostly hemoglobin, and little else.

(The above is not necessarily true for all animals, some have nuclei, but it's the case for mammals, and thus humans.)