Kinetotroph
Akinetotrophorkinetic harvesteris ahypothetical organismthat would usekinetic energyto produce complex molecules likeadenosine triphosphate(ATP). Kinetotrophs could obtain their energy from numerous sources like wind, tides, or currents; this would allow them to inhabit locations with minimal light forphotosynthesis.[1]Kinetotrophs could descend fromchemotrophs,and have been hypothesized to take the form of sedentaryciliatesandreed-like organisms.[2]
There are no known kinetotrophs on Earth, likely because the process is less efficient than other sources of energy like light or chemicals.[2]However, similartransducersystems have been observed in some organisms. For example, some fish possess alateral line organ,which uses cilia to turn the movement of fluid intoelectric signals.[3]
Mechanisms
[edit]The theoretical mechanics that would allow kinetotrophism vary widely. One pathway proposed byDirk Schulze-MakuchandLouis N. Irwininvolves lever-like proteins that would be moved by the flow of fluid. When inside aprotein channelwithcilia-like proteins that could act as channel guards, the levers could allow specific molecules into or out of the cell.[4]Harnessing theGibbs–Donnan effect,sodium ionscould be made to enter the cell and fuel a hydrogen transporter similar to those inmitochondria,thus allowing for energy-storing molecules like ATP to be synthesized.[1]This mechanism would act like abattery;thus, only enough time and a flow of fluid in the range of millimetres per second would be required for the synthesizing of complex molecules.[3]
Another mechanism to derive energy from kinetics would be aspring-like structure. Fluid currents or tides could place pressure on cilia structures, bending them and creatingtensile energy.When the pressure subsides, that tension would be released and could create usable energy.[2]
Habitat
[edit]
It has been proposed that kinetotrophs could exist underneath the ice sheet of theJovianmoonEuropa.These organisms might attach to the underside of the ice sheet, or to substrates on the ocean floor.[1][5]The kinetic energy these organisms would harness could be provided byconvection cells,where currents are created by the varying temperatures of fluid throughout thewater column.[3]
References
[edit]- ^abcSchulze‐Makuch, Dirk; Irwin, Louis N. (2001-03-27)."Alternative energy sources could support life on Europa".Eos, Transactions American Geophysical Union.82(13): 150.Bibcode:2001EOSTr..82..150S.doi:10.1029/EO082i013p00150.ISSN0096-3941.
- ^abcIrwin, Louis (2011).Cosmic biology: how life could evolve on other worlds.Springer. pp. 101, 180, 240.ISBN9781441916464.
- ^abcSchulze-Makuch, Dirk (2008).Life in the universe: expectations and constraints(2nd ed.). Springer. pp. 73–74.
- ^Wicaksono, Adhityo; Cristy, Ghea Putry (2021)."Xenobiology: An expanded semantical review".Notulae Scientia Biologicae.13(2): 10929.doi:10.15835/nsb13210929– via ResearchGate.
- ^Schulz-Makuch, Dirk; Bains, William (2017).The Cosmic Zoo: Complex Life on Many Worlds.Springer. p. 196.ISBN978-3-319-62044-2.