Science center
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.
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 food we had to mix with
watter and then we put it into the tubes.
Biochemical laboratory
Mrs. Marie Vlková, chemistry and
biology teacher, introduced us to the
experiment.
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 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.
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
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