Amino Acid Biosynthesis – Lecture Overview

Sixteen vocabulary flashcards summarizing key terms, pathways, and regulatory concepts in amino acid biosynthesis.

Miller–Urey Experiment (1953)

Lab simulation of early-Earth conditions that generated 11 standard amino acids, supporting the idea that life began in an organic-rich ‘primordial soup.’ Used ammonia, hydrogen, methane, water vapor, and electrical sparks

Primordial Soup Hypothesis

Proposal that the first organisms evolved in a prebiotic environment abundant in organic molecules produced abiotically. As organisms evolved, they began to biosynthesize their own nutrients due to depleted natural organic compounds.

α-Ketoglutarate Family

Glutamate, Glutamine, Proline, Arginine

Pyruvate Family

Alanine, Valine*, Leucine*, Isoleucine (* = essential)

3-Phosphoglycerate Family

Serine, Glycine, Cysteine

Phosphoenolpyruvate/Erythrose-4-Phosphate Family

Tryptophan*, Phenylalanine*, Tyrosine (from Phe in mammals); (* = essential)

Oxaloacetate Family

Aspartate, Asparagine, Isoleucine, Methionine*, Threonine*, Lysine* (* = essential)

Ribose-5-Phosphate Family

Histidine, essential

Glutamate & Glutamine (Nitrogen Donors)

Key carriers that donate the ‑NH₂ group required for the formation of most other amino acids.

Concerted Inhibition

Products from a biomolecule negatively feed back to the enzyme producing the biomolecule; i.e. glutamine (from glutamate) yields AMP, Try, Carbamoyl P, Glucosamine 6-P, His, CTP, which prevent further glutamine production

Amino acid biosynthesis pathways

AAs made from carbon skeleton precursors derived from glycolysis (G6P, R5P, 3Pglycerate, Erythrose-4-P, PEP, pyruvate), CAC (OAA, a-KG), and the PPP

Phenylalanine and tyrosine yields

Tannins, alkaloids (morphine), flavorings, salicylate (aspirin), ligin (rigid polymer)

Tryptophan yields

Auxin (indole-3-acetate; growth hormone)