VEGA MÁRQUEZ GARCÍA 3DS
FOOD AND NUTRITION
FOOD AND NUTRITION
One of the most important activities people do is eating. It depends on factors like: economic, cultural, climatic, etc.
Food supplies the body with nutrients needed to create new structures and mantain the existing ones, as well as the energy neccesary to carry out life functions.
In nutrition, nutrients enter in the cells to be used in different metabolic processes. As different from eating, nutrition is an involutary process. There are four systems involved: digestive, respiratory, circulatory and excretory systems.
NUTRIENTS CAN BE CLASSIFIED INTO TWO GROUPS: INORGANIC AND ORGANIC NUTRIENTS
INORGANIC NUTRIENTS
WATER:
The human body at birth contains 75% of water and in adulthood 60%.
Its principal functions are: solvent (almost all substances dissolve in water), tranport substances, chemical reactions and it regulates the body temperature.
We get water by drinking, eating food that contain water and by metabolic processes (metabolic water).
We expel water by sweat, faeces and urine.
MINERAL SALTS:
They make up aproximately a 4% of body weight. They are essential.
Its functions are to regulate functions for muscle contraction, nerve transmission, etc. And building functions for bones and teeth, also formation of parts of structures such as cell membranes or formation of proteins such us haemogoblin.
We get mineral salts by being dissolved in water, as part of food or added to food, such as salt.
Vegetables and fruit are examples of foods that contain lots of mineral salts.
ORGANIC NUTRIENTS
These are biomolecules found only in food from organic sources, animals and plants.
They are glucids, lipids, proteins and vitamins.
GLUCIDS:
They provide most of the energy.
Monosaccharides (glucose) are the fuel for our cells.
Disaccharides (sucrose, maltose) are digested quickly.
Glycogen: complex carbohydrate.
They come from plant sources (cereals) and from products made with them (sugar).
LIPIDS:
They provide energy or turn into fat that is stored in adipocytes, these cells form adipose tissue.
They come from plant sources (margarine) and animal sources (bacon).
Their functions are: structural, regulatory and they also reserve energy.
PROTEINS:
They are the most important building nutrients and form part of many tissues and organs. They also carry out important functions such us defence of the body and carrying oxygen in the blood.
They come from animal sources (milk) or plant sources (pulses).
VITAMINS:
They must be obtain from the food we eat because human can not synthesize it. Depending on their composition, they can be lipids or proteins. They are very important for growth and many organic processes.
Vitamin in excess can cause disease.
They are found in fresh produce (fruits), they are also in milk eggs, fish, etc.