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I.P.S.I.A. “L. Zanussi”di
Pordenone
Clil project
Alunne: L.Contino; T. De Nardi
Classe: IIC IAM
Disciplina: Scienze
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The nutrition groups are:
• Carbohydrates
• Proteins
• Fat
• Vitamins
• Minerals
• Fibre
• Water
A balanced diet is made up of all the above nutriens.
There are chemical tests for carboydrates, proteins
and fats.
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Carbohydrates consist of starch and types of sugar,
e.g. glucose (the sugar our bodies use for respiration)
and lactose (the sugar in milk).
We need carbohydrates to give us energy.
Starch is made up of smaller glucose molecules joined
together. Plants store glucose as starch.
Glycogen is also a carbohydrate. Animals store
glucose as glycogen. These foods contain a lot of
carbohydrates.
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Add two drops of yellow iodine
solution to food solution.
Solution will turn blue/black if starch is present.
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Add a few drops of Benedict’s solution to food
solution.
Heat in a water bath until it boils.
If glucose is present, an orange precipitate will
form.
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Fats are made fatty acid and glycerol.
We need fat for o store of energy, to make
cell membranes and for warmth
(insulation).
Fat can also be bad for us. Cholesterol is a
fatty deposit that can narrow arteries and
contribute to heart disease.
This food contains a lot of fat:
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•Add 2cm3 of ethanol to the food solution in the
test tube and shake.
•Add 2cm3 of water to the test tube and sake
again.
•Fat is present if the solution turns cloudy white.
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Water makes up approximately 65% of your body
weight. Water is important because:
•Our blood plasma is mainly water.
•Water is sweat that cools us down.
•Chemical reactions in our cells take place in water.
•Waste products are removed from our bodies in water.
•Food and drink contain water.
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We only need these in small amounts, but they
are essential for good health. Vitamins and
minerals are found in fruit, vegetables and
cereals.
Deficiency diseases are caused by a lack of
vitamins and minerals.
Vitamin C keeps the skin strong and supple
without it the skin cracks and the gums bleed.
Vitamin D helps the bones harden in children;
without it the bones stay soft (a disease
called rickets).
We need the mineral iron for making
haemoglobin and the mineral calcium for
healthy bones and teeth.
Deficiency
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Your body cells are mostly made of protein.
Proteins are made up of lots of amino acids.
We need protein to repair and replace
damaged cells or to make new cells during
growth.
These foods contain a lot of protein:
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•Fibre, or roughage, comes from plants.
•Fibre is not actually digested; it just keeps food
moving smoothly through your system.
•Fibre provides something for your gut muscles
to push against. It is a bit like squeezing
toothpaste through a tube.
•It prevents constipation.
These are foods containing a lot of fibre:
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QUICK TEST
•What do we use carbohydrates
for?
•Name the two main carbohydrates.
•What is the chemical test for
starch?
•What is the chemical test for
glucose?
•What do our bodies need fat for?
•How would you test for fat?
•Why is protein important to our
cells?
•What is the chemical test for
protein?
•Why is fibre important?
•What are deficiency diseases
caused by?
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SOLUTIONS
•Energy
•Starch and glucose
•Iodine; a blue/black colour means
starch is present
•Benedict’s solution and heat; an
orange precipitate means glucose is
present
•Store energy, make cell membranes
and insulation
•Ethanol and water; cloudy means fat
is present
•Repair and replace cells, and make
new cells for growth
•Biuret test; if solution turns purple,
protein is present
•It helps food move through your
system and prevents constipation
•Lack of vitamins and minerals
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