Arthur Harden and William
Young
THE Fermentation’s wiz!!
By: Sara B and Ylvie N
Wait … But Who Are They ??
• Arthur Harden is a British biochemist born
on October 12th 1865 . In 1929, he won a
Nobel prize for his work on fermentation
and fermentative enzymes.
• For one of his experiment, he worked with
another English biochemist called William
Young.
How Did They Come Up With This
Experiment??
• Allan Macfadyen, Arthur’s professor,
attempted to make up an anti-zymase. IN
order to do this, he injected a yeast juice in
some animals. From MacFadyen’s results
of this experiment, Harden and Young
knew that phosphates was important in
alcohol fermentation . What they did not
know was How Is phosphate Important…
Okay… Now They Know This!!
What’s Next???
• In order to study the effect of phosphate on the
injected animals, these scientists studied regular
serum in comparison to the effect of the infected
serum on the yeast juice. They were able to
observe 2 things : for one , in the presence of
the serum, the catalyzing capability of Yeast
Juice were greatly diminished. Also, they were
able to observe that the rate of fermentation and
the total amount of products it yielded increased
significantly.
Did They Have a Hypothesis?
• Facing all this experiments, the pair
thought that it might have been due to the
presence of the products proteolysis
(breakdown of proteins or peptides with
amino acids) might exert in antiproteolytic.
3 Types of Fermentation
Continuation…
• A fairly rapid fermentation (Curve 1) where sugar is decomposed
into CO2 and alcohol, and once the inorganic phosphate is
converted into ester or sugar that builds up. When the sugar of the
inorganic molecule stops, the rate of fermentation falls and the build
of ester also stops and the fermentation passes to Type 2 of
fermentation.
• A slow fermentation (Curve 2) in which the rate at which
fermentation occurs is controlled by the rate at which inorganic
phosphate is complete by the hydrolysis (breakdown of compound
due to water) of the phosphoric esters present in the system. The
inorganic phosphate is then reconverted into a sugar-phosphoric
ester enlightened by hydrolysis, then the fermentation proceeds at a
steady rate. This type of fermentation which goes on when sugar is
added from an active yeast and the process is allowed to proceed at
a steady rate.
Continuation….
• Now in the fermentation mixture in which
Type 2 fermentation is introduced of
phosphatase, capable of hydrolysing the
sugar-phosphoric ester therefore the
increasing the rate of supply of inorganic
phosphate. The fermentation also rises.
But this is from Harden and Macfarlane
with unpublished results.
• http://adb.anu.edu.au/biography/youngwilliam-john-9220
• http://humantouchofchemistry.com/arthurharden.htm
• http://www.nobelprize.org/nobel_prizes/ch
emistry/laureates/1929/harden-lecture.pdf