Amino Acids: These are organic compounds composed mainly from carbon, hydrogen, oxygen, and nitrogen atoms. Some also contain sulfur atoms (like those with sulfhydryl groups).
Proteins: These are large biomolecules made up of one or more chains of amino acids. They can have sulfhydryl groups which help maintain their structure.
Disulfide Bridges: These are covalent bonds that can form between two cysteine residues in a protein due to the interaction of their sulfhydryl groups. It's like the bond formed when you press together two pieces of velcro!