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Foxs-In-A-Trenchcoat t1_ix3io45 wrote

They have small molecules in their body called osmolytes (trehalose is one example, which is a nonreducing sugar) that are natural antifreeze. The solutes lower the freezing point of the body's tissues and fluids to much lower than plain water, so the insect may not freeze at all. Or if it does freeze, the osmolytes also prevent the internal water from forming into sharp little ice crystals, which would cause damage to the animals' tissues. The osmolytes also protect biomacromolecules like proteins from being denatured/damaged from harsh environmental conditions.

However, not all individuals survive even with adaptations. Every freeze/thaw cycle kills a lot of them. Or there might be a limit of how low a temperature they can survive.

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perta1234 t1_ix3l0b2 wrote

You are correct. Might just add that for "summer adapted" physiological state, without the antifreezes, it goes other way round sometimes. Getting some warmth now and then helps. In case you know and can share some of that physiology, would be happy to hear more.

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Foxs-In-A-Trenchcoat t1_ix3m2pi wrote

Those are heat shock proteins that an animal manufactures in their own cells. These are small proteins that stabilize other proteins that help to prevent them from being denatured by high temperatures.

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suhdaey t1_ix4jwbc wrote

Is it being a non-reducing sugar critical? Thanks in advance.

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Foxs-In-A-Trenchcoat t1_ix4l097 wrote

Yeah, it's less reactive. Sugars are typically carbon rings, and if they reduce, that means the ring breaks open into a carbon chain. One end of the chain then has an aldehyde group which is available for chemical reactions. Sugars that stay in ring form are more stable, less reactive chemically.

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chouchchair t1_ix5rc1m wrote

Not at all. Glucose, for example, is used as an “antifreeze” compound in several organisms. It’s more about increasing the osmolality in the extra cellular fluid. If this is done effectively in an organism, the extra cellular fluid may freeze, but the water content has been mostly drawn out of the cells themselves so they won’t lyse during freezing.

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