down the rabbit hole towards 37C (/98.6F)

[mellowtigger]

Here's a good example of where my curiosity takes me.

1. It started with a pun on Mastodon, "Murder, She Roti".
2. What is roti? Oh, it's an unleavened bread.
3. What does that leave out? Various leavening agents.
4. Wait, there's a salt-leavened bread? No, that's a bad name, because there's no salt. It used to be stored in hot salt.
5. Wait, there's a bread that rises because of hydrogen instead of carbon dioxide? Yes, that bacterium is Clostridium perfringens.
6. Wait, that bacterium can cause a necrotizing disease, but people put it in their food?! Yes, but cooking destroys the bacteria to safe levels. Apparently. :/
7. If it's "safe", then how does it cause disease? It affects people who are protein deprived, which inhibits their trypsin production, which apparently deprives them of even more protein.
1. Wait, eating sweet potatoes does that too? Apparently so, unless you cook them well.
8. Why is trypsin important in the human body? Because trypsin begins the digestion process of protein molecules in the small intestine.
9. And... wait, what?! "Human trypsin has an optimal operating temperature of about 37 °C."?
1. That's the temperature for people living in the civilized world. For people in the USA, that's exactly 98.6 Fahrenheit.

So, I looked around and eventually found this publication.

Most hydrolyses have been reported at trypsin (EC 3.4.21.4) optimum conditions (pH 7.8 and 37 °C).

So... the obvious questions (and I haven't found any answers yet):

1. Is this molecule why humans evolved a body temperature of 37C/98.6F? If we deviate, then poor nutrition leaves us disadvantaged and subject to evolutionary culling?
2. What does this mean for our falling body temperature?
3. Other animals have different body temperatures (scroll upward to see the chart). Do they rely on some other process to kickstart their protein digestion?
1. I know humans have a weird intestinal digestion process, which is why we can't make use of the vitamin B12-producing bacteria that live in our gut. Other animals, however can use their own internally-hosted bacteria, so we eat their muscles, eggs, and livers to steal their bacteria-produced B12.
4. Are there some animals with the same temperature as humans, and do they have the same small intestine digestive process that we do?

Inquiring minds want to know.

Comments

[armiphlage]

Or it could be the other way - our digestive system uses that molecule because it is compatible with our body temperature. If we had a warmer or cooler body temperature, our digestive system might have developed to use another enzyme.

Atlantic cod use a variant, trypsin Y. It has an optimal temperature of 21 C.

https://www.sciencedirect.com/science/article/abs/pii/S0308814608004238

I love how your mind works!

[mellowtigger]

Oh! I didn't think of the backward influence. Thanks for the idea. Yes, It's what I've repeated here many times over the years. "Everything is connected", which means that systems are very important. So many influences.