1. Unit 2 Food and nutrition

2. Types of Nutrients
• INORGANIC NUTRIENTS
– Water
– Minerals
• ORGANIC NUTRIENTS
– Carbohydrates
– Lipids
– Proteins
– Vitamins

3. Carbohydrates
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They are one of the main dietary components.
Classification:
Monosaccharides.
Disaccharides
Polysaccharides

4. Monosaccharides.
• Formed of a single molecule. They are used
directly by cells.
– Glucose
– Fructose: Fructose is known popularly as fruit's
sugar.
– Galactose
– Ribose.

5. Disaccharides
• They are formed by two monosaccharides.
– Lactose: It´s formed by glucose and galactose. We
can find lactose in the milk.
– Sucrose: It is formed by glucose and fructose. We
can find sucrose in honey. (it is the sugar we use
to cook)
•

6. Polysaccharides
• They are formed by three or more
monosaccharides.
– Glycogen. It is the storage polysaccharide in animals.
Humans can use Glycogen as an energy source by
hydrolysis of the polymer using specific enzymes
– Starch. It is a storage polysaccharide in plant cells, we
can obtain it from potatoes.
– Cellulose. It is the constituent of the cell walls in cell
plants.We can not digest cellulose, because we lack
the specific enzimes that can hydrolize it.

7. • Monosaccharides can be directly absorbed in the
intestine, they dont need digestion.
• Disaccharides and polysaccharides can´t be direclty
absorbed, they must be digested until we obtain from
them monosaccharides.
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If we have high levels of glucose in the blood, part of
it turns into glycogen. Glycogen is accumulated in the
liver and inside the muscles.
• On the opposite if there are low levels of glucose in the
blood glycogen is broken into molecules of glucose.
•

8. Can you think examples of food rich in
carbohydrates?
• Cereals, fruit, vegetables, honey, sweets,
chocolate, sugar, potatoes, pasta, bread, rice.
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• If we eat a lot of carbohydrates our body turns
them into lipids (fat)
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9. Lipids
• They have bigger energetic value but it is
more difficult to absorb them. They can be
stored in the body.
• What types of lipids are there?
• Fats: Saturated and unsaturated.
• Membrane lipids
• Regulatory lipids

10. Saturated fats
• They don´t have double bonds between the
carbon atoms.
• Solid at environment temperature.
• We find them in animal and plant food. A lot of
these fats are bad for our health, specially trans
fats..
• E.g: palm oil, coconut oil.
• We can find them in whole milk, butter, ham, pig
meat, chocolates, pastries and processed foods
made with trans fat from partially hydrogenated
oil, yolk.

11. Unsaturated fats
• They have double bonds between the carbon
atoms.
• In vegetables and sea animals.
• They are usually liquid at environment
temperature.
• They are healthier than saturated fats.
• E.g: Olive oil, dried fruits(avellanas,
almendras, pistachos), sunflower oil, blue fish
(omega3, omega6)

12. Other lipids
• Cholesterol Types???
• ( “bad cholesterol or LDL, good cholesterol or
HDL). Cholesterol can´t move on its own in the
body. It combines with a protein, and a
lipoprotein is formed.
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• Fosfolipids. They form part of the cell
membranes of the cells.
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13. Essential fatty acids
• What are they?
• Fatty acids that can´t be synthesized in the
body and must be obtained from food.
• Their names?
• Linoleic and linoleic acid. These basic fats are
used to build specialized fats called:
– Omega-3
– Omega-6
• Why are they important?
– They are important in the normal functioning of

14. Sources of Omega-3 and Omega-6
• Omega-3
– Salmon, Trout
– Seafood
– Walnuts
• Omega-6
– Sunflower seeds
– Walnuts
– Soya bean
– Corn
– vegetable oils (corn, safflower, soybean,

15. Proteins
• They are made of basic units called amino
acids.
• There are 20 different types of amino acids.
• There are 8 esential amino acids that our body
can not synthetise and therefore we have to
add them in the diet.
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16. • In our diet we can have animal or plant
proteins. The animal proteins have a higher
nutritive value for us.
• Think examples of food rich in:
• Animal proteins:
– meat, fish, cheese, eggs, milk.
• Plant proteins:
– leguminous plants (beans, green beans, peas),
cereals, bread.

17. Homework
• Look info about this minerals, function, food
rich in them, and illnesses due to its lack.
• Calcium
• Magnesium
• Iron
• Iodine

18. • Page 21 activities 3 and 9
• Listen to cd activities 3 and 5
• Page 34 activity 2. Listen to it.

19. Unit 2 Review
• Why do we need to eat and drink?
• What type of nutrients are there?
– INORGANIC AND ORGANIC
• Can you give examples of carbohydrates?
• What polisacharide is known as the energy
store substance in plants?
– STARCH
• What about animals? What is our main energy
store polisacharide?
– GLYCOGEN

20. • What is fibre?
• Can we digest fibre?
• Give examples of food rich in fibre:
– Cereals, corn, wheat, rice, nuts, orange,
mushrooms
• What about proteins? What can you tell us
about them?
– Structure
– Can we make all the amino acids?

21. • How much water do you drink daily?
• How much should you drink?
• Why is water necessary?

22. Tell us THINGS about VITAMINS!
• Give examples of sources of vitamins.
• Can any of the vitamins be made by the
intestinal bacteria?
• If you have high amounts of vitamin C, can
your body get rid of it ? How?
• What about vitamin A? What is its function?
• Vitamins E, K or D?
• Vitamin B12?

23. Do we use energy when we sleep?
• We need energy to maintain
the vital functions.

25. What is this?

28. Check homework
• Page 25- activity 24
• Page 27- activity 26
• Read page 26.
• Do for next week:
• Page 27 activity 35
• Make a list of items that must be included in a
food label.