[HN Gopher] Animals Whose Blood Isn't Red
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       Animals Whose Blood Isn't Red
        
       Author : warrenm
       Score  : 48 points
       Date   : 2023-11-20 13:20 UTC (9 hours ago)
        
 (HTM) web link (animals.howstuffworks.com)
 (TXT) w3m dump (animals.howstuffworks.com)
        
       | ortusdux wrote:
       | There is a condition called Sulfhemoglobinemia wherein you blood
       | takes up sulfur instead of iron and your blood turns green.
        
         | temp0826 wrote:
         | Wikipedia says vulcans have green blood due to copper-based
         | hemocyanin. Seems logical.
        
           | mike_hock wrote:
           | Everything about Vulcans seems logical.
        
             | cli_shall wrote:
             | Fascinating.
        
         | gilleain wrote:
         | Interesting - a minor point, but the sulfur does not seem to
         | replace the iron, but is just an -SH group on the haem.
        
         | kulahan wrote:
         | Wow, that's an extremely green blood if Google's images are to
         | be believed
        
       | markx2 wrote:
       | Minor yet important typo.
       | 
       | "Crocodile icefish frequent brutally cold portions of the sea
       | where the water temperature can plummet all the way down to 28.5
       | degrees Fahrenheit (1.9 degrees Celsius). That's below the point
       | at which fresh water freezes."
       | 
       | 28.5F is minus -1.94C
        
         | croisillon wrote:
         | would be great if there was an easy mnemotechnics to remember
         | at how many degrees Celsius fresh water freezes
        
           | analog31 wrote:
           | It's easy to remember, exactly 100 degrees below the boiling
           | point.
        
             | dekhn wrote:
             | it's just kelvins offset by 273.15!
        
             | dspillett wrote:
             | <pendant>If we are allowing "to one decimal point" as
             | "exact", and are taking about one standard atmospheric
             | pressure, yes.</pendant>
             | 
             | Even at one atmosphere pure water can exist in its solid
             | state at 0.010C.
        
           | KMag wrote:
           | I doubt there's any simple way to remember that non-linear
           | pressure vs. freezing point function for water.
        
         | wolverine876 wrote:
         | > 28.5F is minus -1.94C
         | 
         | Myself, I don't throw stones.
        
       | crazygringo wrote:
       | ...and yet not a single picture of the blood of _any_ of them.
        
         | medstrom wrote:
         | Right?! That'd be the first thing on my agenda if I wanted to
         | write an article with that title.
         | 
         | I'll choose to believe the writers didn't especially have an
         | interest, they were just paid to write.
        
           | dvh wrote:
           | If the news article contains "... caught on video" there's
           | like 50% chance there will be video in that news article.
        
           | moritzwarhier wrote:
           | I didn't read the article, but the infinite scrolling
           | experience, extremely long text and overall site appearance
           | makes me question if this was written by a "journalist" or
           | "author" at all. I might be wrong, sad then, but this page
           | looks SEO 1x1, AI or not.
           | 
           | Manages to quiet down my interest sparked by the headline
           | quite well.
        
       | james_pm wrote:
       | Is this why blood has a metallic taste? It's literally metallic?
        
         | s0rce wrote:
         | I'm pretty sure, yes.
        
           | at_a_remove wrote:
           | I've never bought the official explanation for this. We have
           | just four iron atoms per hemoglobin. But the roughly quarter-
           | billion of these per red blood cell are _in_ the red blood
           | cells, which presumably haven 't all suddenly lysed and
           | dumped their hemoglobin.
           | 
           | I think we should test with blood plasma first. I'm thinking
           | it is the various salts in the plasma we're tasting, not the
           | iron bound up in hemoglobin which is itself trapped inside of
           | red blood cells.
        
             | r2_pilot wrote:
             | I was going to say, it's always been a more copper-y taste
             | to me and that's what I usually read in descriptions of the
             | taste.
        
               | dekhn wrote:
               | I'd describe it more like an umami-rich sauce.
               | 
               | Which it is...
        
               | s0rce wrote:
               | If you are a vampire.
        
             | s0rce wrote:
             | Did some more reading, can't find much conclusive, you
             | might be right, this reddit post is probably one of the
             | better discussions
             | 
             | https://www.reddit.com/r/biology/comments/cqes9/why_does_bl
             | o...
        
         | jacquesm wrote:
         | Yes, iron. You can clearly taste it. That's one of the things I
         | noticed after using a plasmacutter to cut through sheet, the
         | vaporized iron stays afloat long enough that if you take off
         | your mask and get a whiff it smells like blood.
        
           | Night_Thastus wrote:
           | I was under the impression the iron in the blood was in the
           | form of hemoglobin. Does hemoglobin itself have a metallic
           | taste, or is the taste caused by something else in the blood?
        
             | jacquesm wrote:
             | Good question I do not know but I associate the two (blood,
             | iron vapor) very closely. It may well be that the blood
             | also contains some free iron but Iron is so toxic that I
             | doubt that would be enough to taste directly so it may well
             | that haemoglobin itself tastes metallic but it only has a
             | handful of Iron atoms in it compared to a mountain of other
             | stuff.
        
       | jihadjihad wrote:
       | Surprised there is no mention of lobsters, who, like crocodile
       | icefish have colorless blood. For lobsters it appears blue once
       | it comes in contact with oxygen [0].
       | 
       | 0: https://www.fisheries.noaa.gov/national/outreach-and-
       | educati...
        
         | gilleain wrote:
         | Also they miss mentioning
         | https://en.m.wikipedia.org/wiki/Erythrocruorin which is green,
         | but for a different reason than biliverdin in lizards.
         | 
         | Seems it has chlorocruorin in which looks very much like a
         | 'normal' haem (i can't spot the difference off hand).
         | 
         | edit: Ok, from Figure 2 here :
         | https://biomolecules101.wordpress.com/2020/01/17/oxygen-tran...
         | looks like normal heme ('heme b') has an ethenyl group while
         | chlorocruorin has an aldehyde there
        
       | whearyou wrote:
       | How could they leave off Vulcans? Gross oversight
        
       | kulahan wrote:
       | Along a similar line, look into animals that don't sweat clear!
       | Hippos sweat red, so they look like they're just covered in blood
       | sometimes. Horses sweat white, so they look like they're just...
       | well, you can go see for yourself.
        
       | _a_a_a_ wrote:
       | I'm surprised hemocyanin isn't poisonous to us, or at least bad.
       | Ingesting copper just doesn't sound healthy. AFAIC it isn't
       | something we usually do either, so no pressure to evolve a way to
       | metabolise it either.
        
         | dekhn wrote:
         | We eat about 1mg of copper a day. It's an essential trace
         | mineral. You can consume 10mg safely per day.
        
           | _a_a_a_ wrote:
           | Huh. Didn't know. Thanks!
        
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       (page generated 2023-11-20 23:01 UTC)