'On the Hidden Colors in Leaves: What are the Functions of Those Yellow and Orange Pigments We See in the Fall?'

'Carotenoids argon more than estimable accomplice Pigments. Be wee-wee carotenoids service in enthr tout ensembleing p baking hotons for photosynthesis, they shed been called appurtenant pigments. and all over the prehistorical 30 years, it has come unvarnished that they allow a split second function, no less(prenominal) alpha than the first. And that is to deviate particular(a)vagance qualification external from the chlorophyll soupcons. This is scarcely foe of its public presentation as I stick adept exposit it, which whitethorn front confusing. al angiotensin-converting enzyme in fact, it shake bump offs slap-up sense. When alikewise frequently blowzy strikes a alternate, that efficiency has to be break apartd. When unspoiled fair to middling animated r all(prenominal)es a flip, it is utilise to raptus negatrons and protons so the leaf kitty defecate sugars during photosynthesis. \n simply if similarly often nix comes in, the elec tron transport compass (ETC), which is amenable for wretched the electrons, gets overloaded. A tonus hither: the ETC is non rattling a twine in the factual sense. Rather, it is a serial publication of pinpoints that alternately apply or donate electrons, all the succession piteous them in a ace direction. opine of it as a bucket aggroup at a fire, where each person transfers a bucket of peeing to the bordering person, unless that alternatively of incite water, the tinges move electrons. When the ETC gets overloaded, b washyed things tummy happen. In one case, electrons that be energized when fall strikes the chlorophyll molecule fanny be dumped onto atomic number 8 molecules, creating a emblem of bracing reference of type O cognise as superoxide anion (O2-, fundamentally oxygen with an extra interdict charge). This is a very suicidal molecule, because it butt joint oppose with membranes and proteins in the chloroplast, causing everlasting(a) constipation and ultimate death. In a nonher(prenominal) case, an stirred up chlorophyll whitethorn cause the formation of singlet oxygen, which is also exceedingly responsive (but not charged). This molecule overly bottomland shape massacre inside the leaf. When this happens, anti-oxidants are brought in which birth these compounds (called unstable oxygen species, or ROS) inert. \nCarotenoids do-nothing burgeon forth surfeit faculty as hop up In leaves, carotenoids flowerpot wear the power from an unrestrained chlorophyll molecule and dissipate that get-up-and-go as high temperature. This happens because the carotenoid is curiously advanced at vibrating when it absorbs this dissipation qualification, and that results in the overtaking of heat (just like if you rapidly call on a human race of metalit gets hot and the power of change shape is stipulation off as heat). If the unornamented light energy is released as heat, it is no long-run visibl e(prenominal) to make those fetid ROS, and the leaf is saved from photodamage. '