Science center experiments
On Wednesday 25th of April we visited the science center in
Gymnasium Havlíčkův Brod. We saw many interesting
experiments including food and chemical substances. There were
three stages: biochemical laboratory, IR spectrometer and
microscope.
Mrs. Marie Vlková, chemistry
and biology teacher, introduced us
to the experiment.
food we had to mix with watter and
then we put it into the tubes.
We proved the presence
using biuret test. We add sodium
hydroxide and copper sulphate to
every tube. If proteins are present
in the food, the substance turned
violet. We found out that
everything except starch include
proteins. We moved back to the
sugars. Every tube turned black or
formed a silver mirror so we knew
that every food we used contains
sugar, even the olive oil.
Biochemical
laboratory
We did substance analysis.
We wanted to prove the presence of
sugars and proteins in various
food. For sugar proof we had
honey, milk, grapes, apples, olive
oil and oranges. We extracted juice
from fruit and poured it into tubes
separatelly.
We did the same thing with
milk, olive oil and honey. Then we
added Tollen’s reagent, which
contains silver. We mixed it and
shook the tubes. We put them into
hot watter and moved to next
experiment with proteins. There
we had milk, starch, egg white,
cheese, youghurt, soya milk,
protein and chicken meat. Some
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