The Nobel Prize-winning physicist who contributed to the understanding of quarks is Murray Gell-Mann. He formulated the quark model in 1964, proposing that protons and neutrons are composed of smaller particles called quarks. This groundbreaking discovery advanced the field of particle physics and helped organize the understanding of subatomic particles. Gell-Mann's work recognized the importance of symmetry and classification in fundamental physics, influencing subsequent research and theories. His contributions earned him the Nobel Prize in Physics in 1969, solidifying his legacy in the scientific community.