Fill in the blank. Essential amino acids are those that cannot be produced by an organism, e.g. _____ has no essential amino acid, but all amino acids are essential for _______.

MCQS on the biological importance of organic molecules. Topics include bioorganic mechanisms, chirality, lipids, carbohydrates, animo acids, peptides, proteins, nucleic acids, enzymes, coenzymes, and coupled reactions, and lipid, carbohydrate, amino acid, and nucleotide metabolism.