Amino acids bring together acid-base chemistry, stereochemistry, condensation chemistry, and macromolecular structure in one biologically central topic.
Classify amino-acid side chains by polarity and charge behavior.
Predict protonation state and isoelectric-point trends conceptually.
Explain peptide-bond formation and why the peptide bond is planar and conformationally restricted.
Recognize the main levels of protein structure and the interactions that stabilize them.
Checkpoint Questions
Q: Why is the peptide bond planar?
A: Because resonance between the carbonyl and nitrogen gives the C–N bond partial double-bond character.
Q: What determines the isoelectric point conceptually?
A: It is the pH at which the amino acid or peptide has no net charge overall, balancing its acidic and basic ionizable groups.