Albert Imre Szent-Györgyi was born in Budapest, Hungary on September 16, 1893, the second son of Miklos and Josefine Szent-Györgyi. His father, a businessman from a titled family, spent much of his time running a large estate about fifty miles from Budapest. The rest of the family--Josefine, their three sons, and her mother--visited the countryside during the summers, but otherwise stayed in the family's apartment in Pest. Josefine was a talented musician, but her lineage also included several generations of notable scientists, the Lenhosséks. Her brother Mihály, a famous physiologist and professor at the University of Budapest, was a constant presence during Albert's childhood and eventually inspired his interest in science.

Szent-Györgyi remembered himself as "a very dull child" who hated books and often needed a tutor's help to pass his exams. At sixteen, however, he found himself suddenly hungry for knowledge, and began to excel at his schoolwork. He announced to his family that he intended to become a medical researcher, but his uncle Mihály Lenhossék strenuously discouraged the idea; science, he said, had no place for dim-wits such as Albert. Perhaps his nephew could pursue a career in cosmetics, dentistry, or pharmacy, but never science! Lenhossék relented when Szent-Györgyi graduated high school with honors. He entered the Budapest Medical School in 1911. Soon bored with his medical courses, he gravitated to his uncle's anatomy laboratory. Lenhossék allowed him to work there, with one condition: Albert's first research would focus on the anatomy of the human rectum and anus (Mihály apparently suffered from hemorrhoids and hoped to profit from his nephew's investigations.) Szent-Györgyi's first scientific article, published in 1913, therefore dealt with the epithelium of the anus. "Because of my uncle," he often joked later, "I started science at the wrong end."

Szent-Györgyi's medical education was interrupted by World War I. In the summer of 1914 he began serving as an army medic. Though he earned a medal of valor for his bravery, by 1916, after two years in the trenches, he was disgusted with the war and despaired of surviving it. He carefully shot himself through the left humerus, claimed he had been hit by enemy fire, and was sent back to Budapest. While his arm healed, Szent-Györgyi finished medical school and received his MD in 1917. Later that year he married Cornelia ("Nelly") Demeny, the daughter of Hungary's Postmaster General. She accompanied Szent-Györgyi to his next military post, an army clinic in northern Italy. Their only child, Cornelia ("Little Nelly") was born in October 1918, just before the war ended.

Hoping to obtain further scientific training, and escape the post-war chaos in Budapest, Szent-Györgyi took a research position in pharmacology in Pozsony, then a part of Hungary. When Pozsony became part of Czechoslovakia in September 1919, the Hungarians were ordered to leave. After several months back in Budapest, Szent-Györgyi moved on to laboratories in Berlin, Hamburg, and Leiden, gaining experience in biochemistry. In Groningen he began studying biological oxidation and intracellular respiration, processes essential to energy production in living systems. One of his research publications caught the attention of the eminent biochemist Sir Frederick Gowland Hopkins, who offered Szent-Györgyi a Rockefeller fellowship at Cambridge University in 1926. For the next several years, he worked to isolate a reducing substance found in citrus fruit, some vegetables, and adrenal glands. Not sure of its identity, he called it "hexuronic acid." Cambridge awarded him a PhD for the work in 1927. Within two years Szent-Györgyi was able to isolate nearly one ounce of the substance, but made no further progress in establishing its identity.

In 1931, at the invitation of the Minister of Education, Szent-Györgyi returned to Hungary to head the University of Szeged's department of medical chemistry. He proved to be a legendary teacher and unconventional administrator. He quickly assembled a group of young researchers, and set them to work on various biochemical problems. One researcher was a young American post-doctoral fellow, Joseph Svirbely, who had recently worked on vitamin C with Charles G. King at the University of Pittsburgh. Szent-Györgyi asked him to test "hexuronic acid" for anti-scurvy properties. Svirbely soon identified it as vitamin C (now also known as ascorbic acid), and they published this finding in April 1932. King had also published about this several weeks earlier, possibly on the basis of news from Svirbely, and a controversy over priority developed during the next decade.

Szent-Györgyi also investigated respiration in muscle tissue during this period, clarifying the role of dicarboxylic acids (e.g. malic, succinic, and fumaric acids), and identifying the process as a cycle. He correctly defined most of the steps in the process, later known as the "Krebs cycle." Szent-Györgyi was awarded the 1937 Nobel Prize in Physiology or Medicine for "discoveries in connection with the biological combustion processes, with especial reference to vitamin C and the catalysis of fumaric acid."

Meanwhile, Szent-Györgyi continued his research into the metabolic processes of muscle cells. By 1938 he was investigating the biochemistry of muscle movement, which was still poorly understood. He and his team discovered that muscle cells contained a protein, actin, which combined with the known muscle protein myosin to form the complex protein actomyosin. When adenosine triphosphate (ATP) (the primary source of energy in animal cells) was added to actomyosin, the fibers of that protein contracted, thus demonstrating the basic process of movement.

Besides his groundbreaking work on muscle chemistry, Szent-Györgyi became increasingly involved in anti-fascist activities after 1935, and was part of Hungary's anti-Nazi underground during World War II. He spent much of 1944-45 hiding from the Gestapo. When the war ended Szent-Györgyi worked for several years to rebuild Budapest's scientific establishment, hoping that the new Soviet regime would support rather than stifle research in Hungary. He was soon disappointed, and in 1947 emigrated to the United States with his second wife, Marta, and settled in Woods Hole, Massachusetts.

Szent-Györgyi continued to study muscle contraction chemistry, with funding from the National Institutes of Health, the American Heart Association, and others. His laboratory at the Marine Biological Laboratory at Woods Hole soon drew a number of European émigrés. He did pioneering work on the electron microscopy of muscle during this time, and discovered that muscle tissue stored in a 50 percent glycerin solution retained its contractility, so that researchers need not keep supplies of fresh muscle on hand. Such preparations became widely used in muscle research. In 1954, Szent-Györgyi received a Lasker Award for his contributions to understanding cardiovascular diseases through basic muscle research.

After the late 1950s, Szent-Györgyi's research focused increasingly on the application of quantum physics to biochemical problems, particularly the sub-molecular aspects of energy transport mechanisms in tissues. His elaborate theory about the mechanisms of cancerous cell growth argued that structural proteins in cells exchanged and conducted electrons in a very controlled way, making the cell's chemical work possible. Disruption of this electron-transfer system by free radicals (highly reactive molecules lacking an electron), Szent-Györgyi suggested, could push cells into the uncontrolled proliferative state that characterizes cancer. Many molecular biologists were skeptical about this theory, but Szent-Györgyi's innovative perspectives opened new avenues of investigation that are currently being explored.

Szent-Györgyi was also notable for his rejection of American scientific research conventions. Devoted to doing basic research, he eventually refused to write funding applications that required him to say what the investigation would produce. His laboratory at Woods Hole flirted with financial disaster many times, and was rescued several times by funding from unlikely sources, such as the Armour meat company. He was offered several academic appointments over the years, but declined them, fearing that teaching and faculty responsibilities would leave no time for research. His last thirteen years of work were funded by the National Foundation for Cancer Research, a private foundation set up especially to support Szent-Györgyi.

During the 1960s and 1970s, Szent-Györgyi, like many scientists, spoke out against the Vietnam war and the growing threat of nuclear weapons. He published many articles and several books addressing these topics, including The Crazy Ape (1970).

Although he held no academic appointments after moving to the United States, most of the many scientists who worked with Szent-Györgyi over the years gave his teaching skills high praise. They drew inspiration from his personal charm, his infectious enthusiasm for science, and his intuitive, playful approach to scientific questions. Szent-Györgyi never retired, and continued working at his MBL lab until several months before his death, on October 22, 1986.

Szent-Györgyi published over 300 scientific articles and 11 books during his career. He received the Nobel Prize in 1937 and a Lasker Award in 1954. The U.S. National Academy of Sciences elected him a member in 1956. On his first return visit to Hungary in 1973, he received an honorary doctorate from the Medical University of Szeged; that institution was renamed Albert Szent-Györgyi Medical University in 1987.