How does extremely low pH cause proteins to coagulate?

Question

What are the four levels of protein structure?

Answer 1

pH changes the way, mostly hydrogen bonds interact in the protein, but sometimes if very strong the acid can break the protein structure down completely.

primary - the sequence of amino acids in a row Lys-Asp-etc-etc
secondary - a basic shape like a alpha chain or a helix
tertiary - this is like the final actual shape of the protein, how it is folded.
quaternary - several proteins linked together like silk of collagen