Can humans and other animals using pigments such as melanin be considered photosynthetic?

Question

With Vitamin D and melanin in humans, conversion of light energy into chemical energy takes place, right? Similar processes must occur in other animals. So, photosynthesis?

Answer 1

Yes it is photosynthesis. Photosynthesis of vitamin D in the skin is how it is referred to in all journal articles.
http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=3030826&cmd=showdetailview&indexed=google
http://www.photobiology.com/reviews/previtamin/index.html
"The skin has been recognized as the site for the sun-mediated photosynthesis of vitamin D3 until recently, however, very little was known about either the sequence of events leading to the formation of vitamin D3 in human skin or the factors that regulate the synthesis of this hormone."
http://www.nature.com/jid/journal/v77/n1/abs/5615643a.html
Melanin reaction is an energy synthesis in fungi
http://en.wikipedia.org/wiki/Radiotrophic_fungus
Dr Dadachova of Albert Einstein College of Medicine says "It's pure speculation but not outside the realm of possibility that melanin could be providing energy to skin cells..."
http://www.treehugger.com/files/2007/05/radiation-loving_shrooms.php

Photoelectrochemical properties of melanin
"Melanin is to the animal kingdom like chlorophyll to the vegetal kingdom. Melanin collects energy from lower-energy radiation sources, kicks electrons into excited states, initiating a process that would end up producing chemical energy, similar to the way in which photosynthesis supplies energy to plants. However, the precise roles of melanin during this process are unknown. Here we show that the increase in the electron-transfer properties of melanin is independent of the energy of the incident photons. We found in controlled in vivo assays that melanin has the remarkable capability of converting lower-energy radiation towards a more useful form of energy." Quoted from Dr Arturo Solis-Herrera's prepublication document.
Artificial photosynthesis is studying melanin as a basis for structure-function-relationships in photoconductivety.
http://books.google.com/books?id=-3ZJb4ft4G0C&pg=PA58&lpg=PA58&dq=photosynthesis+melanin&source=web&ots=SC2dXEAG9Y&sig=HhcuU46-IrSJN9XOCplhesCRKNs#PPA57,M1

Photobiology & photochemistry is a research field looking at the interactions of light and organisms. This can cover more than synthesis as bioluminescence, photoperiodism, photomorphology, and vision also come under this field.
American Society for Photobiology
http://www.pol-us.net/ASP_Home/index.html
http://www.pol-us.net/
http://www.blackwellpublishing.com/journal.asp?ref=0031-8655

Answer 2

The term photosynthesis is reserved for those organisms using excited photons to create chemical energy in the form of ATP. It is a specific biochemical pathway. Although you are correct that we can derive certain vitamins from sunlight, these are considered cofactors and not high energy molecules like ATP.

Answer 3

Despite gardengallivant's obvious expertise in botany, mammals don't derive energy from light. As was mentioned elsewhere, ATP production, the creation of usable energy for metabolism, is only gotten at for mammals through digestion.

You have to look deeper at what 'Chemical energy' means. Although not all plants are photosynthetic, all mammals are heterotrophic.

Answer 4

It relies upon one the way you're relating the be conscious. it fairly is the authentic definitions of the be conscious. you settle on. a million A multicellular organism of the dominion Animalia, differing from vegetation specially ordinary features including ability for locomotion, nonphotosynthetic metabolism, suggested reaction to stimuli, limited growth, and caught actual shape. 2 An animal organism different than a human, fairly a mammal. 3 a guy or woman who behaves in a bestial or brutish way. 4 A human seen with appreciate to his or her actual, as adversarial to religious, nature. 5 a guy or woman having a exact flair or set of pastimes: “that rarest of musical animals, an instrumentalist who's as comfortable on a podium with a stick as he's enjoying his device”