Some proteins can fold into their 3D structure on their own just based on the chemical properties of amino acids, and others need the help of special proteins called "chaperone proteins" like the chaperonin protein from lesson 4.
Regardless of the protein's folding independence, the way proteins fold depend on the amino acids. Hydrophilic amino acids "love water" (and each other), as do do charged amino acids. But hydrophobic amino acids are "afraid" of water and will not want to be close to it.
