Question

more complex configurations of proteins can be denatured by abiotic factors such as a change in the ph. what does this break? all amino acids van der waals forces alpha helix hydrogen bonds

Explanation:

Protein denaturation by pH - change breaks non - covalent bonds. Hydrogen bonds are non - covalent and affected by pH. Amino acids are linked by peptide bonds (not broken in denaturation). Van der Waals forces are weak but hydrogen bonds (more relevant in protein structure) are key here. Alpha helix is a secondary structure stabilized by hydrogen bonds.

Answer:

hydrogen bonds