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1 天前 · Bacteria (/ b æ k ˈ t ɪər i ə / ; sg.: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell.They constitute a large domain of prokaryotic microorganisms.Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats.
2 天前 · Staphylococcus aureus is a gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. [1] .
3 天前 · CRISPR (/ ˈ k r ɪ s p ər /) (an acronym for clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea. These sequences are derived from DNA fragments of bacteriophages that had previously infected the prokaryote. ...
4 天前 · Properties. Production. Uses. Reactions. Health and safety. See also. Notes. References. External links. Acetic acid / əˈsiːtɪk /, systematically named ethanoic acid / ˌɛθəˈnoʊɪk /, is an acidic, colourless liquid and organic compound with the chemical formula CH3COOH (also written as CH3CO2H, C2H4O2, or HC2H3O2 ).
4 天前 · Botulinum toxin, or botulinum neurotoxin (commonly called botox ), is a highly potent neurotoxic protein produced by the bacterium Clostridium botulinum and related species. [23] . It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, thus causing flaccid paralysis. [24] .
3 天前 · Omega−3 fatty acids, also called Omega−3 oils, ω−3 fatty acids, Ω-3 Fatty acids or n−3 fatty acids, [1] are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond three atoms away from the terminal methyl group in their chemical structure. [2] They are widely distributed in nature, being important ...
19 小時前 · Tuberculosis ( TB ), also known colloquially as the " white death ", or historically as consumption, [7] is an infectious disease usually caused by Mycobacterium tuberculosis (MTB) bacteria. [1] Tuberculosis generally affects the lungs, but it can also affect other parts of the body. [1] Most infections show no symptoms, in which case it is ...
