Green "Blood"

[YT2095]

how is it possible to have green (what I assume is) Blood?

 

I was examining my roses the other day and it`s infested with the usual Greenfly, I squashed some of them and took a close look, they`re not just green on the otside , but thier "Blood" is too.

it doesn`t smell of anything in particular either, like a plant smell or anything (I didn`t taste any).

 

so I`m wondering, how can green blood be possible and what is it that makes it green?

[Skye]

My guess is that it uses the oxygen carrier protein hemocyanin, rather than hemoglobin that we have. Hemocyanin is blue when it has oxygen bound to it.

[YT2095]

I`m wondering about the "Cyan" word part, is that related to the color, or does it have a CN group?

[Skye]

I'd say it's because of the colour, I don't think it has cyano groups.

[Mokele]

AFAIK, there are no CN groups in Hemocyanin, and the color comes from the copper atoms that are used in Oxygen transport.

 

You're also, by smashing the fly, mixing a lot of body fluids together, and my guess is that the green comes from the mix of Hemocyanin, digestive enzymes and food in the process of being digested.

 

Mokele

[Mag]

Oh, interesting question.

 

What aboug insects with Orange blood?

 

I know ive smushed a few and everything inside is orange.... although, im not sure if it is blood or just their insides.

[Mokele]

Probably just insides. Various insects sequester or produce unusual chemicals for various reasons (mate attraction, becoming noxious to predators, etc), so that could explain it.

 

Mokele

[Glider]

Octopi have green blood. It is not iron based as is the blood of mammals, it is copper based.

[Skye]

Yeah they have hemocyanin too.

[Dak]

Hemocyanin is blue when it has oxygen bound to it.

haemocyanin contains copper as opposed to iron. the deoxyginated form (copper I) is coulourless, and the oxygenated form (copper II) is blue. as coppor rust is green, id assume that, upon squishing the insect, the haemocyanin is fully oxidated in the air (to copper III?), whereupon the insects blood goes green.

 

Same as the fact that the deoxyginated blood in our veighns is blue*, as it contains iron(II)oxide, but if you cut yourself it comes out red, as it oxidises in the air to iron(III)oxide (ironII being blue, ironIII being red)

 

*apparently. I'v always been a tad scepticle about this, but i guess our veigns are blue, so maybe?

[Glider]

Veins (i.e. just the vessels) are the same colour as arteries; sort of pinky red. They are thinner walled than arteries though, and this means that the colour of the deoxygenated blood shows through (looking blue ish). Deoxygenated blood is just very dark red/purple. You can see the colour if you take venous blood directly into an anaerobic sample container (no oxygen).

[YT2095]

Great answers guys, Thanks alot

[Skye]

haemocyanin contains copper as opposed to iron. the deoxyginated form (copper I) is coulourless' date=' and the oxygenated form (copper II) is blue. as coppor rust is green, id assume that, upon squishing the insect, the haemocyanin is fully oxidated in the air (to copper III?), whereupon the insects blood goes green.

 

Same as the fact that the deoxyginated blood in our veighns is blue*, as it contains iron(II)oxide, but if you cut yourself it comes out red, as it oxidises in the air to iron(III)oxide (ironII being blue, ironIII being red)

 

*apparently. I'v always been a tad scepticle about this, but i guess our veigns are blue, so maybe?[/quote']

The thing you're missing here, and it's not super important, is that you aren't dealing simply with oxides, but with complexes of copper and iron that can have oxygen as a ligand. In the case of deoxygenated hemocyanin the copper(I) atoms are bound to the protein directly via three histidine residues, whereas the iron(II) atoms in hemoglobin have four binding sites occupied by a porphyrin molecule, which forms the heme group, and a fifth site which occupied by a histidine. Then in each case oxygen comes along and binds, and up the oxidation states. However, two oxygen atoms form bridging ligands between two copper atoms in hemocyanin, so it's a pretty weird looking 5 coordinate system for each copper.

 

Here's a link describing each:linky link

 

All this stuff means that the energy levels are changed for these molecules from normal iron or copper oxides, and when you change energy level you change colour. The deoxyhemoglobin is Fe(II) but it is in the high spin state, i.e. some electrons are promoted to a higher energy level and are unpaired. This results in the dark maroon colour of deoxygenated blood. What exactly happens when it binds oxygen is still not exactly known. For one thing, oxyhemoglobin is paramagnetic. The most likely is that a low spin iron(III) double bonds to one of the oxygen atoms in O₂. That's why the O₂ in the oxyhemoglobin in the link above is bent.

[Dak]

^ OMG, episode x of 'when biochemistry gets complicated and confusing'!!!

 

urm, am i right in thinking that the iron molecule('s eletrons?) get contorted by the interaction with the haem bit, so its not the same as most iron(III) (hence the different colour, which is part way between the red of iron(III) and the blue of iron(II))? more like iron(2.9) than iron(III)?

 

also, does the Cu in haemocyanin become oxidised to green copper(II) in the air, do ya recon?

 

Veins (i.e. just the vessels) are the same colour as arteries; sort of pinky red. They are thinner walled than arteries though, and this means that the colour of the deoxygenated blood shows through (looking blue ish). Deoxygenated blood is just very dark red/purple. You can see the colour if you take venous blood directly into an anaerobic sample container (no oxygen).

ok, in that case: if deoxyginated blood is dark red/purple, and the veins are pinky-red, why do they look blue? surely the pinky-red arteries should contain the blue part of the purply blood, and only let the red wavelengths out (like a red filter over a light), hence the veins should appear red...

[AzurePhoenix]

What is the basis for the Green-Blooded Lizard's green blood? Would it be similar to that of the "lower" phyla?

[gib65]

I remember learning about this in a biology course. Blood (the red kind) is essential to larger animals because we need some way to carry nutrients and other essentials around the body, whereas in smaller animals like insects, the foods they ingest and the oxygen they breath doesn't need to travel far and can be transported to all parts of the body by simple osmosis. It is the red blood cells which are specialized for carrying around nutrients and other such important goodies for the body.

[Skye]

urm, am i right in thinking that the iron molecule('s eletrons?) get contorted by the interaction with the haem bit, so its not the same as most iron(III) (hence the different colour, which is part way between the red of iron(III) and the blue of iron(II))? more like iron(2.9) than iron(III)?

Well yes the molecular orbitals the electrons are in get distorted. They still have normal oxidation states (which are due to the charge of the molecules involved), but they have different energies.

also, does the Cu in haemocyanin become oxidised to green copper(II) in the air, do ya recon?

I don't know, I haven't heard of it but that doesn't mean it couldn't happen.

[Mokele]

What is the basis for the Green-Blooded Lizard's green blood?

 

A bile-like compound of unknown use, possible to deter predators by making the species distasteful.

 

Mokele

[cool_b74]

good answers i didn't know that there is a relation for the blood color with electronic configuration, wavelength, oxidation states , thankyou

[Daecon]

So, theoretically, could Vulcans (from Star Trek) have green blood?

[Bluenoise]

So, theoretically, could Vulcans (from Star Trek) have green blood?

 

Pssst they don't actually exist you know....

[Daecon]

Yeah, but if there are really living creatures in nature that have green blood, could a human-type organism also have green blood?

[starbug1]

Yeah, but if there are really living creatures in nature that have green blood, could a human-type organism also have green blood?

 

If this human-type organism has an extra component to its blood, such as an enzyme or a slightly different composition, it's a very real possibilty. If you think about it, the color of human blood (red, purple-blue) is familiar to us, but it could just as well be green or black or yellow, and we think twice...thus proving why the human-type aliens depicted in movies always seem to have green blood.

[Glider]

ok, in that case: if deoxyginated blood is dark red/purple, and the veins are pinky-red, why do they look blue? surely the pinky-red arteries should contain the blue part of the purply blood, and only let the red wavelengths out (like a red filter over a light), hence the veins should appear red...

That would be the case if the blood was luminous and purple light was coming from within and shining through the wall of the vein. This is not the case though. The light we see is coming from outside and is reflected from the surface of the vein. Evidence for the result can be found by looking at your own veins