That’s mostly correct. Unless they are stabilized by internal disulfide bonds, most proteins will denature (lose their natural shape) in boiling water. However, it takes much harsher conditions, such as boiling concentrated acid, to actually break the bonds between the amino acids which make up the protein chain. When that happens, it’s called hydrolysis, not denaturation. Anyway, when a globular, i.e. round shaped, protein like ovalbumin denatures, its’ peptide chain goes from a neatly wrapped compact configuration, like a ball of string, to a random, spread out shape, like a ball of string string after the cat has got to it. This spread out tangle of linked amino acids gets tangled up with all the other similar proteins and you end up with a great big solidified mess.
There’s actually not much classical chemistry involved here, just molecules changing shape and getting caught up with each other. There are few covalent or ionic bond changes involved in denaturation, and the subsequent gel formation, just a lot of elaborate physical chemistry.
Yes, same thing with Alzheimers plaques, irreversible protein denaturation. Figuring out to reverse* that* is a big deal these days.