Editing Venom (section)

==Mechanisms==
{{Main|Toxin}}
[[File:1poc.png|thumb|right|[[Phospholipase A2]], an [[enzyme]] in bee venom, releases fatty acids, affecting [[Calcium signaling|calcium signalling]].]]

Venoms cause their biological effects via the many [[toxin]]s that they contain; some venoms are complex mixtures of toxins of differing types. Major classes of toxin in venoms include:<ref name="Harris2004">{{cite journal |last=Harris |first=J. B. |title=Animal poisons and the nervous system: what the neurologist needs to know |journal=Journal of Neurology, Neurosurgery & Psychiatry |volume=75 |issue=suppl_3 |date=September 2004 |doi=10.1136/jnnp.2004.045724 |pmid=15316044 |pmc=1765666 |pages=iii40–iii46}}</ref>

* [[Necrosis|Necrotoxins]], which cause necrosis (i.e., death) in the cells they encounter. The venoms of [[Viperidae|vipers]] and [[bee]]s contain [[phospholipase]]s; viper venoms often also contain [[trypsin]]-like [[serine proteases]].<ref name=Raffray>{{cite journal |last1=Raffray |first1=M. |first2=G. M. |title=Apoptosis and necrosis in toxicology: a continuum or distinct modes of cell death? |journal=Pharmacology & Therapeutics |volume=75 |issue=3 |pages=153–177 |year=1997 |pmid=9504137 |doi=10.1016/s0163-7258(97)00037-5 |last2=Cohen}}</ref> 
* [[Neurotoxin]]s, which primarily affect the nervous systems of animals, such as [[Ion channel#Ion channel blockers|ion channel toxins]]. These are found in many venomous taxa, including [[mamba]]s,<ref>{{cite web|url=http://cogs.csustan.edu/~tom/bioinfo/groupwork/cobra/cobra-venom.ppt|title=Neurotoxins in Snake Venom|access-date=2019-12-26}}</ref> [[Latrodectus|black widow spiders]], [[scorpion]]s, [[box jellyfish]], [[cone snail]]s, [[centipede]]s and [[blue-ringed octopus]]es.<ref name="Dutertre Lewis 2006 pp. 661–670">{{cite journal |last1=Dutertre |first1=Sébastien |last2=Lewis |first2=Richard J. |title=Toxin insights into nicotinic acetylcholine receptors |journal=Biochemical Pharmacology |volume=72 |issue=6 |year=2006 |doi=10.1016/j.bcp.2006.03.027 |pmid=16716265 |pages=661–670}}</ref> 
* [[Myotoxin]]s, which damage muscles by binding to a receptor. These small, basic [[peptide]]s are found in [[snake]] (such as [[rattlesnake]]) and [[lizard]] venoms.<ref name="pmid12709056">{{cite journal |last1=Nicastro |first1=G. |others=Franzoni, L.; de Chiara, C.; Mancin, A. C.; Giglio, J. R.; Spisni, A. |title=Solution structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom |journal=Eur. J. Biochem. |volume=270 |issue=9 |pages=1969–1979 |date=May 2003 |pmid=12709056 |doi=10.1046/j.1432-1033.2003.03563.x |s2cid=20601072 |doi-access=free }}</ref><ref name="PUB00001595">{{cite journal |last1=Griffin |first1=P. R. |last2=Aird |first2=S. D. |title=A new small myotoxin from the venom of the prairie rattlesnake (Crotalus viridis viridis) |journal=FEBS Letters |volume=274 |issue=1 |pages=43–47 |year=1990 |pmid=2253781 |doi=10.1016/0014-5793(90)81325-I|s2cid=45019479 |doi-access=free |bibcode=1990FEBSL.274...43G }}</ref><ref name="PUB00005315">{{cite journal |last1=Samejima |first1=Y. |last2=Aoki |first2=Y. |last3=Mebs |first3=D. |title=Amino acid sequence of a myotoxin from venom of the eastern diamondback rattlesnake (Crotalus adamanteus) |journal=Toxicon |volume=29 |issue=4 |pages=461–468 |year=1991 |pmid=1862521 |doi=10.1016/0041-0101(91)90020-r|bibcode=1991Txcn...29..461S }}</ref><ref name = whittington>{{cite journal |last1=Whittington |first1=C. M. |last2=Papenfuss |first2=A. T. |last3=Bansal |first3=P. |last4=Torres |first4=A. M. |last5=Wong |first5=E. S. |last6=Deakin |first6=J. E. |last7=Graves |first7=T. |last8=Alsop |first8=A. |last9=Schatzkamer |first9=K. |last10=Kremitzki |first10=C. |last11=Ponting |first11=C. P. |last12=Temple-Smith |first12=P. |last13=Warren |first13= W. C.|last14=Kuchel |first14=P. W. |last15=Belov |first15=K. |display-authors=3 |title=Defensins and the convergent evolution of platypus and reptile venom genes |journal=Genome Research |date=June 2008 |volume=18 |issue=6 |pages=986–094 |pmid=18463304 |doi=10.1101/gr.7149808 |pmc=2413166 }}</ref>
* [[Cytotoxicity|Cytotoxins]], which kill individual cells and are found in the [[apitoxin]] of honey bees and the venom of black widow spiders.<ref name="Sobral Sampaio Falcão Queiroz 2016">{{cite journal |last1=Sobral |first1=Filipa |last2=Sampaio |first2=Andreia |last3=Falcão |first3=Soraia |last4=Queiroz |first4=Maria João R.P. |last5=Calhelha |first5=Ricardo C. |last6=Vilas-Boas |first6=Miguel |last7=Ferreira |first7=Isabel C. F. R. |display-authors=3 |title=Chemical characterization, antioxidant, anti-inflammatory and cytotoxic properties of bee venom collected in Northeast Portugal |journal=Food and Chemical Toxicology |volume=94 |year=2016 |doi=10.1016/j.fct.2016.06.008 |pmid=27288930 |pages=172–177 |hdl=10198/13492 |s2cid=21796492 |url=https://bibliotecadigital.ipb.pt/bitstream/10198/13492/3/345.pdf }}</ref><ref name="Peng Dai Lei Liang pp. 3267–3274">{{cite journal |last1=Peng |first1=Xiaozhen |last2=Dai |first2=Zhipan |last3=Lei |first3=Qian |last4=Liang |first4=Long |last5=Yan |first5=Shuai |last6=Wang |first6=Xianchun |display-authors=3 |title=Cytotoxic and apoptotic activities of black widow spiderling extract against HeLa cells |journal=Experimental and Therapeutic Medicine |volume=13 |issue=6 |date=April 2017 |doi=10.3892/etm.2017.4391 |pmid=28587399 |pmc=5450530 |pages=3267–3274}}</ref>