You lipids,also known as fats, are a class of biological molecules formed by fatty acids and alcohol. In general, they present a whitish or yellowish color and stand out because they are not soluble in water, but dissolve in organic solvents such as ether and benzene. They are found abundantly in animal and plant organisms and act, among other functions, as an energy reserve and structural components.
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Lipid classification
We can classify the lipids into three groups:simple, compounds and derivatives. You simple lipids are those that, when they undergo hydrolysis (breakdown of a molecule by the Water) total, give rise only to fatty acids and alcohols. Examples are fats, oils and waxes.
You compound lipids are those that have, in addition to fatty acids and alcohols, other additional substances. This group includes, for example, phospholipids, which also contain phosphoric acid and a nitrogenous compound. Finally, we have the
derived lipids, which can be defined as substances obtained by hydrolysis of other lipid groups. As an example of derived lipids, we have fatty acids, fat-soluble vitamins, hydrocarbons and pigments.Fats and Oils
Fats and oils are lipids of similar chemical structure, being formed by three fatty acid molecules bonded to a glycerol molecule. The difference between fat and oil refers to the physical state of the lipid. While fats are generally solid at room temperature, oils are usually liquid.
Phospholipids
Phospholipids are extremely important lipids for all living things. without them, none cell would exist, since phospholipids are essential components of cell membranes. THE plasma membrane and the membranes of cell organelles are formed by a bilayer of phospholipids with several proteins inserted.
Read more: Cells animatethere and vegetable - main characteristics and differences
steroids
Steroids are a very important group of lipids, being the cholesterol one of the best known. Unlike what many people think, cholesterol is essential for our body, being a component of cell membranes and precursor of other steroids, such as sex hormones. In humans, cholesterol is obtained through food and is also synthesized in the liver. It is noteworthy that, despite its importance, problems in cholesterol metabolism can trigger diseases cardiovascular, such as atherosclerosis.
“Good cholesterol" and "bad cholesterol"
HDL and LDL are lipoproteins that ensure the transport of cholesterol in our blood. O HDL (High Density Lipoproteins or High Density Lipoproteins) works by removing the excess cholesterol present in the tissues, taking it to the liver, where it will be degraded. HDL is also known as “good cholesterol”.
O LDL (Low Density Lipoproteins or Low Density Lipoproteins), in turn, acts by transporting cholesterol to cells, being called "bad cholesterol". The high concentration of LDL in the blood plasma it is considered a risk factor for the development of cardiovascular disease. To learn more about the topic of this topic, read: HDL and LDL.
Importance of lipids
Lipids are an extremely important class of molecules, displaying a number of biological functions. We can highlight the functions of lipids:
Power supply.
Insulator that guarantees the conduction of the nerve impulse.
Protects against heat loss.
Protects against mechanical shock.
Acts in the absorption of vitamins.
Waterproofs surfaces subject to dehydration, such as the surface of fruits.
Participates in the composition of biomembranes.
Participates in the formation of hormones.
Helps in the absorption and transport of fat-soluble vitamins.
Lipid-rich foods
Many people see lipids as villains in food, however, all nutrients must be ingested to ensure a healthy diet. It is important, however, do not over-consume this nutrient, because its consumption in large quantities is related, for example, with the development of cardiovascular problems and obesity.
the lipids are found both in plant foods. and in foods of animal origin. As an example of foods rich in lipids, we have: avocados, nuts, almonds, fatty red meats, eggs, butter, yellowish cheeses, margarine, olive oil, fish, chocolates, among others.
