Overview
Early life and career
Krebs studied medicine and developed an early interest in biochemical processes that underpin health and disease. In the 1930s, political changes in Germany led him to continue his research in Britain, where he combined clinical insight with laboratory investigation. His dual training helped him pose clinically relevant biochemical questions and to design experiments that clarified complex chemical pathways in living tissue.
Major discoveries
Two discoveries define Krebs's scientific reputation:
- Urea cycle — the metabolic sequence by which mammals convert excess nitrogen into urea for safe excretion. This clarified how the body disposes of amino‑acid nitrogen.
- Citric acid cycle (Krebs cycle) — a central sequence of reactions by which cells oxidize acetyl groups to produce energy carriers (such as NADH and FADH2) used in respiration. The cycle became a cornerstone concept for biochemistry and physiology.
These insights showed that metabolism proceeds through ordered cycles and linked biochemical steps to cellular energy production.
Impact and applications
Krebs's work reshaped multiple fields: it provided a framework for understanding cellular respiration, informed studies of nutrition and exercise physiology, and underpinned clinical approaches to metabolic disorders. Laboratory techniques for tracing metabolites and mapping pathways grew directly from his experimental style.
Awards, legacy and notable facts
For his achievements Krebs received the Nobel Prize in Physiology or Medicine in 1953. The citric acid cycle is commonly referred to as the "Krebs cycle" in textbooks and courses worldwide. Beyond the eponym, his career exemplifies the productive interplay between medicine and basic science: he trained and influenced generations of researchers and left a lasting conceptual structure for studying metabolism.