History of vitamins: Who is credited with the discovery and isolation of vitamin C (ascorbic acid) from biological sources?

Introduction / Context:
Vitamin C (ascorbic acid) is a key dietary antioxidant and cofactor in collagen biosynthesis. Knowing the scientists behind its discovery helps anchor historical progress in nutrition and biochemistry.

Given Data / Assumptions:

• Timeframe: early 20th century biochemical discoveries.
• Isolation from adrenal glands and paprika led to ascorbic acid characterization.
• Different scientists popularized or expanded vitamin research later.

Concept / Approach:
Albert Szent-Györgyi isolated and identified ascorbic acid, earning the Nobel Prize in Physiology or Medicine (1937) for his work on biological combustion and vitamin C. Others in the options contributed to different fields.

Step-by-Step Solution:
Match scientist to contribution: Szent-Györgyi → discovery and isolation of vitamin C.Differentiate from Linus Pauling, who advocated high-dose vitamin C later, but did not discover it.Paul Berg: recombinant DNA pioneer; Kary Mullis (misspelled) invented PCR.

Verification / Alternative check:
Historical accounts and Nobel citations attribute discovery/isolation directly to Szent-Györgyi.

Why Other Options Are Wrong:

• Paul Berg: DNA research, not vitamin C discovery.
• Linus Pauling: promotion of vitamin C; not its discoverer.
• Kary Mullis: PCR, unrelated to vitamin C discovery.

Common Pitfalls:
Equating advocacy or later research with original discovery; distinguish discovery from popularization.

Final Answer:
Albert Szent-Gyorgyi