BIOCHEMICAL PATHWAYS: Moris
Friedkin and Albert Lehninger
By: Isabella Boushey, Camille
Santos, & Ingrid Harb
Albert Lehninger
• American biochemist born on February
17th, 1917 in Bridgeport, Connecticut.
• Attended Wesleyan University as an
English major
• Went to the University of Wisconsin where
he studied biochemistry and received his
Ph.D in 1942
• Received several faculty positions at the
University of Chicago and University of
Wisconsin
• Went to the John Hopkins University
School of Medicine
• Author of several classical texts such as
Biochemistry, The Mitochondrion, and
Bioenergetics.
Morris E. Friedkin
• Born on December 30th, 1918 in Kansas City,
Missouri.
• Attended Kansas City Junior College from where he
received an A.A. in chemistry
• Continued his studies at Iowa State College from
where he received a B.S. in chemistry and an M.S. in
analytical chemistry
• Enrolled in the doctorate program at the University
of Chicago where he became one of the graduate
students of Albert Lehninger
• Received his Ph.D in 1948
• Received different faculty jobs at different places
• Devoted the rest of his life to teaching and research
• Research focused on folic acid metabolism, the
biochemical basis of the cell cycle and cell growth,
the use of radioactively labeled molecules in
biochemical research, molecular pharmacology, etc..
Timeline
• 0. Eduard Buchner and Hans Buchner – discovers cell- free
fermentation
• 1. Arthur Harden and William Young - in 1929, discovered ATP
• 2. Gustav Embden - first to discover and link together all the steps
involved in the conversion of glycogen to lactic acid
• 3. Otto Meyerhof & Jakub Parnas – known for The most common
type of glycolysis is the Embden-Meyerhof-Parnas (EMP pathway)
• 4. Otto Heinrich Warburg – 1931, his research into cellular
respiration showed that cancer thrives in anaerobic (without oxygen)
or acidic conditions.
• 5. Albert Szent-Györgyi - was the first to isolate vitamin C, and his
research on biological oxidation provided the basis for Krebs' citric
acid cycle
• 6. Hans Adolf Kreb - 1937 Identification of citric acid cycle or "Krebs
Cycle"
Experiments and Findings
• First started working with and studying fatty
acids and how they work in the body
• Expanded interest to studying whole cell extracts
• Aim was to isolate a specific set of enzymes that
catalyzed fat metabolism
• Separated the mitochondria through using dense
sugar solution without damaging other
organelles
Experiments and Findings
• Set up a chilled centrifuge in a refrigerator
• Found that the isolated mitochondria could break
down fatty acid chains, while the remaining parts of
the cell could not
• The mitochondria also contained the enzymes for
the citric acid cycle, as well as for the production of
ATP
• It could not begin the breakdown of glucose
• Lehninger identified the location of nearly all the
major energy reactions in the cell
Centrifuge
Experiments and Findings
• Lehninger's findings became
very important in cell biology
• It was the first time that a
specific function of a cell’s
organelle had been proven
• This discovery showed that all
functions of the cell were
separated into different
organelles that could be
studied individually
Experiments and Findings
• Had been concluded that for each oxygen the cell consumes three ATP
molecules are produced
• Lehninger showed with the help of his student Morris Friedkin, “the
suspected role of electron transport through the cytochrome system.”
Experiments and Findings
• Deduced that ATP was
produced from high energy
electrons that are produced
from NADH which is produced
during the Kreb’s Cycle
• Able to show how NADH could
be produced by using βhydroxybutyrate
• He measured the oxygen
consumption during this
process using a classic
apparatus designed by Warburg
Experiments and Findings
• Made important conclusions on how ion
concentrations affected reaction rates
• Shown through the synthesis of ATP through the
ETC when there is a high concentration of
protons on the intermembrane space, which
leads to protons diffusing from a high
concentrated area to a lower concentrated area.
This happens when the protons pass through the
ATP synthase and trigger the reaction of the
production of ATP.
References:
• "Albert L. Lehninger." Medical Archives of The Johns Hopkins Medical
Institutions. N.p., n.d. Web. 17 Oct. 2012.
<http://www.medicalarchives.jhmi.edu/sgml/lehninger.html>.
• "forthcoming in New Dictionary of Scientific Biography." forthcoming in
New Dictionary of Scientific Biography. N.p., n.d. Web. 17 Oct. 2012.
<http://www.tc.umn.edu/~allch001/papers/lehninger.pdf>.
• "Friedkin, Morris. []." SNAC. N.p., n.d. Web. 17 Oct. 2012.
<http://socialarchive.iath.virginia.edu/xtf/view?docId=friedkin-morriscr.xml>.
• "Mitochondria: A Historical Review." Mitochondria: A Historical Review.
N.p., n.d. Web. 17 Oct. 2012.
<http://jcb.rupress.org/content/91/3/227s.full.pdf>.
• "The ATP Requirement for Fatty Acid Oxidation: the Early Work of Albert
L. Lehninger." THE JOURNAL OF BIOLOGICAL CHEMISTRY. N.p., n.d.
Web. 17 Oct. 2012. <http://www.jbc.org/content/280/14/e11.full.pdf>.