Chromoproteins and fluorescent proteins in coral

[Sea_Student]

I'm just wondering what is the simple difference between chromoproteins and fluorescent proteins in coral? I've searched the web and browsed this forum and can't find an easy-to-understand explanation.

 

[Formulator]

Chromoproteins just have to have a colored cofactor (cofactor is kind of like baggage that certain proteins carry around or associate with to perform a specific function). Not all colors are fluorescent. For example your blood is red because of the chromoprotein hemoglobin, which carries iron in its heme cofactor. It is not a fluorescent protein because it does not fluoresce, or “glow”. Fluorescent proteins are similar, but they emit radiation when hit by UV light.

 

[Sea_Student]

Thank you for your reply. Very helpful.

 

[Sea_Student]

Why do corals need Chromoproteins?

 

[Formulator]

Why do corals need Chromoproteins?

That is partially what gives coral its various colors. Not all the colors of a coral are fluorescent. They are also important for photosynthesis in the zooxanthellae symbionts of the coral.

 

[Sea_Student]

Thanks for your replies,
I know corals' proteins and colouration can be a bit of a complicated subject, but do you mind explaining how chromoproteins help zooxanthellae to photosynthesize?

 

[carri10]

Photosynthesis is all about capturing light energy and converting it into chemical energy. First part of that process is to 'capture' the light energy. This is done with Chlorophyll when light energy of a certain wavelength (colour) is absorbed by electrons in the chlorophyll molecule. These electrons are then able to pass this into chemical energy through a chain of reactions (eventually taking CO2 and H2O and making Glucose - C6H12O6). Chlorophyll only adsorbs certain light wavelengths. Chromoproteins help this process by capturing light from other wavelengths (less efficient ones than chlorophyll) and passing the energy in their electrons to a different part of the chain of reactions to make chemical energy.

 

[Sea_Student]

Thanks @carri10 . Really helpful.