I think these postings are very intersting. Forgive me for a little free-association, but I find this a stimulating topic. Our hbg has four binding sites for oxygen molecules, with binding strength influenced by pH. More acidic environments give us a lower binding strength (eg in tissues), less acidic with stronger binding strength (eg in lungs), hence the hbg picks up oxygen in the lungs and releases in the tissues. And as was previously posted, C02 is a metabolic product that is absorbed in the tissues and released in the lungs without any specific carriers. And of course CO is fatal as it binds in the four hbg sites/molecule more strongly than O2 under "normal" pressues, hence the effective treatment of hyperbaric O2 as an effort to simply drive the reaction through higher O2 pressures.
So then CO2, our metabolic waste product, dissolves as CO2+H20 (acid) in the bloodstream, and the subsequent pH changes are critical to our hbg oxygen uptake and release cycles. And then we have another problem; if we create a mechanical transport system such as that of hbg, we may loose the pH affect and hence our O2 cycles break down.
Now, this pH/CO2 business requires something approaching an aqueous solution. Maybe that has something to do with why it is these fancy organic transport solutions end up with problems. And not to forget, breathing is one example of a behavior can be controlled to a degree but has a sort of "failsafe override" - and O2 has no part in what forces our body to breathe. It's the pH sensors in the aorta that will trigger the autonomic breathing response.
I still suggest that are critical, fundamental, structural differences between fluid breathers and gas breathers. These are in simple mechanics and the associated energy used in the process of gas exchange. Gas breathers of course have the two-way path, with fluid breathers maintaining a one-way path. There is another important issue, that of temperature management. Gas breathers have nasal passages for warming, filtration, moisturization and sampling (smelling). Creatures that live it fluids manage heat exchange through a structure called "Rete mirabile". Documentation of this structure is readily available through network searches. While they are poikliothermic, some fish maintain internal cruising muscle temperatures above ambient through this structure. To be more inclusive, gas exchanges occur within this "wonderful net" as well as heat.
Anyway, I posit that there are many issues beyond exchange of gasses; gas breathing critters are just simply built different in many ways. but I would very much like to have an option.
In any event, this remains one of my favorite topics.
S.
So then CO2, our metabolic waste product, dissolves as CO2+H20 (acid) in the bloodstream, and the subsequent pH changes are critical to our hbg oxygen uptake and release cycles. And then we have another problem; if we create a mechanical transport system such as that of hbg, we may loose the pH affect and hence our O2 cycles break down.
Now, this pH/CO2 business requires something approaching an aqueous solution. Maybe that has something to do with why it is these fancy organic transport solutions end up with problems. And not to forget, breathing is one example of a behavior can be controlled to a degree but has a sort of "failsafe override" - and O2 has no part in what forces our body to breathe. It's the pH sensors in the aorta that will trigger the autonomic breathing response.
I still suggest that are critical, fundamental, structural differences between fluid breathers and gas breathers. These are in simple mechanics and the associated energy used in the process of gas exchange. Gas breathers of course have the two-way path, with fluid breathers maintaining a one-way path. There is another important issue, that of temperature management. Gas breathers have nasal passages for warming, filtration, moisturization and sampling (smelling). Creatures that live it fluids manage heat exchange through a structure called "Rete mirabile". Documentation of this structure is readily available through network searches. While they are poikliothermic, some fish maintain internal cruising muscle temperatures above ambient through this structure. To be more inclusive, gas exchanges occur within this "wonderful net" as well as heat.
Anyway, I posit that there are many issues beyond exchange of gasses; gas breathing critters are just simply built different in many ways. but I would very much like to have an option.
In any event, this remains one of my favorite topics.
S.
