Bacteria Notes PDF

Bacteria: all bacteria contain a cell membrane and cytoplasm Some bacteria have flagella or fimbriae (the latter of which are similar to cilia) As a result of the analagous structures shared between bacteria and eukaryotes, it can be challenging to develop medications that target only ba...

Bacteria: all bacteria contain a cell membrane and cytoplasm Some bacteria have flagella or fimbriae (the latter of which are similar to cilia) As a result of the analagous structures shared between bacteria and eukaryotes, it can be challenging to develop medications that target only bacteria Bacterial flagella and eukaryotic flagella, however, are different enough that antibacterial vaccines can specifically target bacterial flagellum Additionally, several antibiotics can target the bacterial ribosome; recall that the bacterial ribosome is much smaller than the eukaryotic ribosome, too On Earth, approximately 5*10 bacteria are present, which substantially outnumbers the number of plants and animals combined. The relationship between humans and bacteria can differ depending on the particular bacteria; for example, some bacteria are mutualistic symbiotes (i.e., both humans and bacteria benefit from their relationship) - e.g., bacteria in the human gut produce vitamin K and biotin (i.e., vitamin B ). This also prevents overgrowth of harmful bacteria Other bacteria may be pathogens or parasites (i.e., provide no benefit to the host and cause disease) - e.g., Chlamydia trachomatis is a commonly sexually transmitted infection and lives inside the cells of the reproductive tract - e.g., Chlostridium tetani causes tetanus, and it lives outside of cells where it may produce toxins that enter the bloodstream Classi cation of Bacteria by Shape Most bacteria exist in one of three shapes: 1) cocci (spherical); 2) bacilli (rod-shaped); 3) spirilli (spiral-shaped) Examples: Streptococcus pyogenes (cocci); Escherichia coli (bacilli); Treponema pallidum (spirilli; causes syphylis)