WORLD OF MICROBIOLOGY AND IMMUNOLOGY Euler-Chelpin, Hans von205•
tions. This photosynthetic process is a feature of the micro-
scopic eukaryotes called algae.
Other internal organization of eukaryotes includes lyso-
somes, which contain enzyme that digest food that is taken into
the eukaryote. The lysosomerepresents a primitive stomach.
Eukaryotic cells such as amoeba possess an internal
scaffolding that helps provide the shape and support to the
cell. The scaffolding consists of filaments that are made of
protein. Depending on the protein the filaments are designated
as actin filaments, microtubules, and intermediate filaments.
Eukaryotes such as amoebae and algae are part of a
group that is called Protista. More commonly, members of the
group are referred to as protists.
The evolutionary branching of eukaryotes from
prokaryotes involved the acquisition of regions specialized
function within the eukaryotic cell. One of these regions, the
mitochondria, was likely derived from the habitation of a
eukaryote by a bacterium. Evidence from ultrastructural and
molecular studies for a symbiosis between a bacterium and a
eukaryote is convincing. Over time, the bacterium became
truly a component of the eukaryotic cell. Today, however, the
DNA of the mitochondria remains unique, with respect to
eukaryotic nuclear DNA.
Likewise, chloroplasts may have had the origin in a
symbiotic relationship between a cyanobacterium and a
eukaryotic cell. Current evidence does not support the devel-
opment of any other eukaryotic organelle from a prokaryotic
ancestor.See alsoBacterial ultrastructure; Cell cycle and cell division;
Mitochondrial DNAEUKARYOTIC CELLS, GENETIC REGULA-
TION OF•seeGENETIC REGULATION OF EUKARYOTIC
CELLSEEuler-Chelpin, Hans vonULER-CHELPIN, HANS VON(1873-1964)
Swedish biochemistHans von Euler-Chelpin described the role of enzymesin the
process of fermentationand also researched vitamins, tumors,
enzymes, and coenzymes. He was an important contributor in
the discovery of the structure of certain vitamins. In 1929, he
shared the Nobel Prize in chemistry with Arthur Harden for
their research on the fermentation of sugar and enzymes.
Euler-Chelpin’s research has far-reaching implications in the
fields of nutrition and medicine.
Hans Karl Simon August von Euler-Chelpin was born in
Augsburg in the Bavarian region of Germany on February 15,
1873, to Rigas, a captain in the Royal Bavarian Regiment, and
Gabrielle (Furtner) von Euler-Chelpin. His mother was related
to the Swiss mathematician Leonhard Euler. Shortly after his
birth, Euler-Chelpin’s father was transferred to Munich and
Euler-Chelpin lived with his grandmother in Wasserburg for a
time. After his early education in Munich, Würzburg, andUlm, he entered the Munich Academy of Painting in 1891
intending to become an artist. Eventually, he changed his pro-
fessional interest to science.
In 1893, Euler-Chelpin enrolled at the University of
Munich to study physics with Max Planck and Emil Warburg.
He also studied organic chemistry with Emil Fischer and A.
Rosenheim, after which he worked with Walther Nernst at the
University of Göttingen on problems in physical chemistry.
This post-doctoral work in the years 1896 to 1897 was under-
taken after Euler-Chelpin received his doctorate in 1895 from
the University of Berlin.
The summer of 1897 was the first of several that Euler-
Chelpin spent in apprentice roles in Stockholm and in Berlin.
He served as an assistant to Svante Arrheniusin his laboratory
at the University of Stockholm, becoming a privatdocent
(unpaid tutor) there in 1899. Returning to Germany that sum-
mer, he studied with Eduard Buchner and Jacobus Van’t Hoff
in Berlin until 1900. His studies during this period centered on
physical chemistry, which was receiving a great deal of atten-
tion at that time in both Germany and Sweden. Recognition
came early to Euler-Chelpin for his work. He received the
Lindblom Prize from Germany in 1898.
It was evident during this time that there were new
opportunities in organic chemistry. The new equipment used
to measure properties could be applied to the complexities of
chemical changes that took place in organisms. Euler-
Chelpin’s interests, therefore, shifted to organic chemistry. He
visited the laboratories of others working in the field, such as
Arthur Hantzsch and Johannes Thiele in Germany and G.
Bertrand in Paris. These contacts contributed to his developing
interest in fermentation.
In 1902, Euler-Chelpin became a Swedish citizen and in
1906, he was appointed professor of general and organic
chemistry at the University of Stockholm, where he remained
until his retirement in 1941. By 1910, Euler-Chelpin was able
to present the fermentation process and enzyme chemistry into
a systematic relationship with existing chemical knowledge.
His book, The Chemistry of Enzymes,was first published in
1910 and again in several later editions.
In spite of being a Swedish citizen, Euler-Chelpin
served in the German army during World War I, fulfilling his
teaching obligations for six months of the year and military
service for the remaining six. In the winter of 1916–1917, he
took part in a mission to Turkey, a German ally during World
War I, to accelerate the production of munitions and alcohol.
He also commanded a bomber squadron at the end of the war.
After the war, Euler-Chelpin began his research into the
chemistry of enzymes, particularly in the role they played in
the fermentation process. This study was important because
enzymes are the catalysts for biochemical reactions in plant
and animal organisms. An integral aspect of Euler-Chelpin’s
work with enzymes was to identify each substrate (the mole-
cule upon which an enzyme acted) in the reaction. He suc-
ceeded in demonstrating that two fragments that split from the
sugar molecule were disparate in energy. He further illustrated
that the less energetic fragment, which is attached to the phos-
phate, is destroyed in the process. Apart from tracing the phos-
phate through the fermentation sequence, Euler-Chelpinwomi_E 5/6/03 2:13 PM Page 205