Biology: The Study of Life
Biology is a discipline that belongs to the Natural Sciences. Its main objective is to study the origin, evolution and properties possessed by all living things. The word biology comes from Greek and means “study of life” (bios, life and logos, study or treaty).
Science: A method for obtaining knowledge about nature.
Technology: In biology, the application of scientific knowledge of engineering to solve biological problems.
Scientific method: way of gathering information and testing ideas. It consists of 4 steps:
– Observation – Hypothesis
– Experimentation – Conclusion
Note: In addition to being accurate, should consist of a record, whether written or a movie, or any other form, as this is the experiment data.
Hypothesis: Possible answer to a question about the nature or some other phenomenon, based on observations, readings, and knowledge of a scientist.
Experimentation: Scientific evidence of the hypothesis, this generally included two groups: “control” group and the group “experimental”, differences in behavior or condition of these, known as “variable factor.
Conclusion: it is not known whether the hypothesis is or is not correct. If the experiment supports the hypothesis, it is correct, and vice versa.
Apart from the scientific method, there are older methods, and others that are commonly used by us in everyday life.
Empirical Method:
The method is used because the observation, we formulate a hypothesis, is experienced, and come to a conclusion, it is used every day to find the answer to the phenomena before us, so it is based on the experience of a person.
Deductive Method:
This part of general knowledge, to find the answer to particular facts.
Inductive Method:
Part of particular knowledge to account for general facts.
Biology often relies on other sciences, like mathematics in statistics, geography for the study of habitats and areas inhabited by living things, in chemistry to know its composition, etc …
Biology depart branches, which specialize in a particular phenomenon or study, including:
Taxonomy: Sort and classify living things according to their kinship.
Cytology studies the cells.
Parasitology: Study parasites.
Embryology: Investigates the development of the new being from conception to adulthood.
Anatomy: Study the structures that make up living things.
Physiology: Study the functioning of organisms.
Histology: Study of tissues.
Anthropology: Study the man physically and morally.
Ornithology: Study the birds.
Bacteriology: Study the bacteria.
Virology: Examines the virus.
Biophysics: Study the behavior of matter in the biological environment.
Biotechnology: Study of biology with technology applications.
Ecology: Study the relationships established between living organisms and their environment.
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1. Why do we eat?
Thinking about everything we do during the day (walking, running, jumping, think ….) and what makes our body (breathing, hear, see …) while the blood circulates through the body performing functions very important; understand that our body runs continuously, even when we sleep. For this man, like all living things, need food to:
Replace losses of material consumed by living organism activity.
Produce substances necessary for the formation of new tissues, encouraging growth.
Transforming the energy contained in food into heat, motion and work.
Classification of food by their origin:
Foods are classified by their origin into three groups:
The vegetable: vegetables, fruits, cereals.
The animal origin: meat, milk, eggs.
The mineral origin: water and salt minerals.
Each of these foods give our body substances that are essential to its operation and development.
These substances are:
The hydrates of carbon (bread, flour, sugar, pasta), high value energy.
The proteins (meats, eggs, dairy, legumes) necessary for growth and tissue formation.
The lipids (fats and oils) energy producers.
Water and minerals in proportions variables for the balance of body functions.
The vitamins, complex chemicals in small quantities, but essential to the smoothstate of the organism.
Classification of food by its description
Dairy foods (milk, casein, cream, butter, cheese)
Carnea and related foods (meat, eggs)
Starchy foods (cereals, flour)
Plant foods (vegetables and fruits)
Sugary foods (sugars, honey)
Fatty foods (oils, fats, margarine)
Beverages (alcoholic beverages, or no alcohol, syrups, vegetable juices, fermented beverages, wines and products related spirits)
And fruitive stimulants (cocoa and chocolate, coffee and substitutes, tea, yerba mate)
Corrective and interveners (spices and vegetable seasonings, mushrooms edible yeast, yeasts and derivatives, salt and compound salts, sauces, dressings or dressings, vinegars)
A good diet should be balanced and complete, ie must be present all the mentioned groups and cover all the needs of the individual.
2. What are nutrients?
The nutrients or principles are all chemicals eating normal food members, such as starch, vegetables, milk fat, etc..
Essential nutrients are nutrients or early members of the body, the absence of the regime or decrease below a threshold, leads after a time variable a deficiency disease. Example of essential nutrients are: some amino acids, vitamin A, iron, calcium, and so on.
Pyramid power:
To stay healthy, people need to eat different foods and liquids. The basic food pyramid describes the quality and quantity of food daily need for nutrients.
Basic Food Pyramid Servings per day
Bread, Cereal, Rice, Pasta
6-11 servings
3. Types of food
Food can be classified into breads and cereals, legumes or vegetables, tubers and rhizomes, fruits and vegetables, meat, fish, eggs, milk and dairy products, fats and oils and sugars, jams and syrups.
The group of breads and cereals including wheat, rice, maize and millet. They are rich in starch and are an easy and direct source of supply of calories. Although the protein is not abundant in cereals integral, The large quantity consumed significant amounts, which, however, be complemented with other protein foods to get all the essential amino acids. The white flour and polished rice are low in nutrients, but, like all whole grains that contain the germ and the outer layer of the seed, wheat and rice provide fiber to the body: the B vitamins thiamin, niacin and riboflavin and the minerals zinc, copper, manganese and molybdenum.
Legumes or pulses cover a wide variety of beans or beans, peas, peas, lentils and beans and even peanuts. They are rich in starch, but they provide far more protein than cereals or tubers. The scale and nature of amino acids in legumes is similar to meat. Their chains of amino acids are often complementary to those of rice, maize and wheat, which are the staple foods in many countries.
The tubers and rhizomes include various types of potato, cassava and taro. They are rich in starch and relatively low in protein, but provide a variety of vitamins and minerals.
Fruits and vegetables are a direct source of many minerals and vitamins that are lacking in the diets of cereals, especially vitamin C of citrus fruits and vitamin A from the carotene in carrots and leafy. Are present in vegetables sodium, cobalt, chlorine, copper, magnesium, manganese, phosphorus and potassium. The cellulose from vegetables, almost impossible to digest, provides the necessary support to pass the food through the digestive tract. Many of the most fragile-soluble vitamins found in fruits and vegetables, but are very easily destroyed by excessive cooking.
Meat, fish and eggs provide all the essential amino acids the body needs to assemble its own proteins. The meat contains 20% protein, 20% fat and 60% water. The viscera are sources rich in vitamins and minerals. All fish contain a high percentage of protein, and oils from some of them are rich in vitamins D and A. Egg white is the most concentrated form of protein that exists.
The milk and dairy products include whole milk, cheese, yogurt and ice cream, all known for its abundance of protein, phosphorus and calcium in particular. Milk is also rich in vitamins but no iron and, if pasteurized, no vitamin C. Although milk is essential for children, excessive consumption by adults can produce acids, unsaturated fatty acids that accumulate in the system circulation.
Fats and oils include butter, lard, tallow and vegetable oils. All are high in calories, but apart from butter and some vegetable oils like palm, contain few nutrients.
The sugars, jams and syrups are consumed in large quantities in some countries where they constitute a large proportion of carbohydrate intake. Honey or maple syrup are composed of more than 75% of sugar and contain few nutrients. Excessive consumption of sugar causes cavities.
Dietary Directions
In general, scientists recommend the following: eating a variety of foods, maintaining ideal weight, avoiding excess fats and oils, saturated fat and cholesterol, eat foods with adequate starch and fiber, avoiding excess sugar and sodium, and in If drinking alcohol, do so moderately.
Essential Nutrients
Nutrients are classified into five major groups: proteins, carbohydrates, fats, vitamins and minerals. These groups comprise a total of approximately 45 to 50 substances that scientists believe are essential to maintaining health and normal growth. Apart from water and oxygen, amino acids also include about eight blocks of proteins, four and ten water-soluble fat-soluble vitamins, minerals ten and three electrolytes. Although carbohydrates are an energy source, are not considered essential, since for this purpose can transform proteins.
Calorie
The amount of heat needed to raise the temperature of 1 gram of water from 14.5 to 15.5 ° C. At other times specified temperature range. The usual definition is that 1 thermochemical calorie equals 4.1840 joules (J).
In engineering uses a somewhat different calorie, calorie international equivalent to 1 / 860 watt-hour (4.1868 J). A large calorie or kilocalorie (Cal), often also called calorie equals 1,000 calories a gram, and is used to indicate dietary energy value of food.
In the metabolism of energy, the unit used is usually the kilocalorie, which is the amount of energy required to raise by 1 degree Celsius temperature of 1 kg of water. Carbohydrates have an average content of 4.1 kilocalories (17 joules) per gram, protein 4.2 (17.5 joules), and fat of 9.3 kcal (39 joules).
Carbohydrates are the most abundant food type in the world, while fats are the fuel more concentrated and easier to store. If the body depletes its reserves of fats and carbohydrates, can be directly used dietary protein or protein tissue break down its own fuel to generate. Alcohol is also a source of energy that produces calories per gram. The cells of the body can not oxidize the alcohol, so the liver has to process to become fat, which is then stored in the same liver or adipose tissue.
Protein
The function of the protein is essential to produce body tissue and synthesize enzymes, somehormones such as insulin, that regulate the communication between organs and cells, and other complex substances, which govern the processes of the body. Proteins animals and plants are not used in the same way they are eaten, but digestive enzymes must break them down into amino acids that contain nitrogen. Readily available animal protein or vegetable. Of the 20 amino acids that make proteins, eight are considered essential (leucine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.) Ready to be taken through food. If these essential amino acids are not present at the same time and in specific proportions, the other amino acids, all or in part, can not be used to build human proteins. Therefore, to maintain health and growth is very important to a diet containing essential amino acids. When there is a lack of any of them, the other amino acids are converted into energy-producing compounds and their nitrogen is excreted. When ingested in excess protein, which is common in countries with diets rich in meat, extra protein is broken down into energy producing compounds. Because proteins are scarce rather than carbohydrates but also produce 4 calories per gram, meat eating in excess, when there is demand for reconstruction of tissues in the body, it is an inefficient way to procure energy. The animal foods contain complete proteins because they contain all essential amino acids. In most diets is recommended to combine animal protein with vegetable protein. It is estimated that 0.8 grams per kilo of weight is healthy daily dose for normal adults.
Apart from intervening in the growth and maintenance cell, proteins are responsible for muscle contraction. Digestive enzymes are proteins, like insulin and most other hormones, immune system antibodies and hemoglobin, which transports oxygen in the blood. The chromosomes, which transmit hereditary characteristics in the form of genes, are composed of nucleic acids and proteins.
Many diseases and infections cause a continued loss of nitrogen in the body. This problem must be compensated by higher consumption of dietary protein. Moreover, children also need more protein per kilogram of body weight. A protein deficiency accompanied by lack of energy gives rise to a form of protein-energy malnutrition known of stagnation, characterized by loss of body fat and worn muscles.
Minerals
Inorganic minerals are needed for structural reconstruction of body tissues as well as participating in processes such asaction of systems enzyme, muscle contraction, nerve reactions and blood clotting. These mineral nutrients, which must be supplied in the diet, are divided into two classes: macro, such as calcium, phosphorus, magnesium, sodium, iron, iodine and potassium and trace elements such as copper, cobalt, manganese, fluorine and zinc .
Calcium is needed to develop the bones and maintain its stiffness. Milk and its derivatives are the main source of calcium.
Phosphorus was also present in many foods and especially in milk, is combined with calcium in bones and teeth. It plays an important role in energy metabolism in cells, affecting carbohydrate, lipid and protein.
Magnesium, present in most foods, is essential to human metabolism and very important to maintain the electrical potential of nerve and muscle cells.
Sodium is present in small amounts in most natural products and foods rich in processed and salty foods. It is also present in the extracellular fluid, where it has a regulatory role. Too much sodium causes edema, which is a superacumulación extracellular fluid. Currently there evidence that excess salt in the diet contributes to high blood pressure.
Iron is necessary for the formation of hemoglobin, the pigment of red blood cells responsible for transporting oxygen. However, this mineral is not easily absorbed by the digestive system. In men found in sufficient quantities, but women of menstrual age, which need nearly twice as much iron due to the loss that occurs during menstruation, usually have deficiencies and should take iron easy to assimilate.
Iodine is essential for the synthesis of thyroid hormones. Deficiency causes goiter, a swelling of this gland in the lower neck. Insufficient iodine intake during pregnancy can lead to cretinism or mental retardation in children.
The trace elements are inorganic substances that appear in the body in minute quantities but are essential for good health. Little is known of its operation, and almost everything that is known of these relates to the manner in which his absence, especially in animals, affects health. Microcells appear in sufficient quantities in almost all foods.
Among the most important trace elements copper is present in many enzymes and proteins, which contains copper, blood, brain and liver. The copper deficiency is associated with the inability to use the iron to form hemoglobin. Zinc is also important for the formation of enzymes. It is believed that zinc deficiency prevents normal growth and, in extreme cases, causes dwarfism. It has been found that fluoride, which is deposited mostly in bones and teeth, is a necessary element for growth in animals. Among the other trace elements can include chromium, molybdenum and selenium.
Vitamins
Any of the organic compounds that the body needs for metabolism, to protect health and to ensure proper growth in children. Vitamins are also involved in the formation of hormones, blood cells, nervous system chemicals and genetic material. The various vitamins are not chemically related, and most of them has a different physiological action. Usually act as catalysts, combining with proteins to create metabolically active enzymes that in turn produce important chemical reactions throughout the body. Without vitamins many of these reactions would take place more or cease altogether. However, much remains to have a clear understanding of the intricate ways in which vitamins act on the body.
The 13 vitamins identified are classified according to their ability to dissolve in fat or water. Fat-soluble vitamins A, D, E and K, are consumed together with foods that contain fat and, because they can be stored in body fat, you do not take them every day. Water-soluble vitamins, eight from group B and vitamin C, can not be stored and therefore must be consumed frequently, preferably every day (except for some B vitamins, as we shall see later).
The body can make vitamin D, all others must be ingested through the diet. The lack gives rise to a wide range of metabolic disorders and others. A well-balanced diet contains all the necessary vitamins, and most people who follow such a diet can correct any previous deficiency of vitamins. However, people who follow special diets, suffering from intestinal disorders that prevent normal absorption of nutrients, or who are pregnant or breast-feeding their children, may need special supplements of vitamins to sustain its metabolism. Apart from these real needs, there is also a popular belief that vitamins provide a remedy for many diseases, from colds to cancer, but in fact the body quickly eliminates most of these preparations without absorbing them. In addition, fat-soluble vitamins can block the effect of other vitamins and even cause serious poisoning if taken in excess.
Vitamin A
Vitamin A is a primary alcohol color pale yellow derived from carotene. Subsequent to the formation and maintenance of the skin, mucous membranes, bones and teeth, in the light and the reproduction. An early failure symptoms is night blindness (difficulty in adapting to darkness). Other symptoms are excessive dry skin, lack of secretion of the mucous membrane, causing susceptibility to bacterial invasion, and dry eyes due to malfunction of the tear, a major cause of blindness in children in underdeveloped countries.
The body gets vitamin A in two ways. One is manufactured from carotene, a vitamin precursor found in vegetables such as carrots, broccoli, pumpkin, spinach, cabbage and sweet potato. The other is absorbing and list of organisms that feed on plants. Vitamin A is found in milk, butter, cheese, egg yolk, liver andfish liver oil. Excess vitamin A can interfere with growth, stop menstruation, damage red blood cells from the blood and cause skin rashes, headaches, nausea and jaundice.
Vitamins B
Also known by the name B-complex vitamins, are fragile substances, soluble in water, several of which are especially important to metabolize carbohydrates.
B1
Thiamine or vitamin B1, a colorless crystalline substance, acts as a catalyst in the metabolism of carbohydrates, allowing acid metabolism piru vico and making carbohydrates release their energy. Thiamine is also involved in the synthesis of substances that regulate the nervous system. The lack of thiamine causes beriberi, characterized by muscle weakness, inflammation of the heart and leg cramps and in severe cases, heart attack and even death. Many foods contain thiamine, but few bring in substantial amounts. Foods richest in thiamine are pork, organ meats (liver, heart and kidneys), yeast of beer, lean meats, eggs, green leafy vegetables, whole grains or enriched, wheat germ, berries, nuts and vegetables. When they were grinding grain removes most of the grain is rich in thiamine, hence the probability that white flour and refined white rice lacks this vitamin. The practice, fairly widespread, to enrich flour and cereals has partly removed the risk of a lack of thiamine, but still occurs in alcoholics who suffer from deficiencies in nutrition.
B2
Riboflavin or vitamin B2, like thiamine, it acts as a coenzyme, ie, must be combined with a portion of another enzyme to be effective in the metabolism of carbohydrates, fats and especially in the metabolism of proteins involved in the transport of oxygen. It also acts in the maintenance of mucous membranes. The insufficiency of riboflavin could be complicated if there is lack of other B vitamins Its symptoms, not as defined as the lack of thiamine, are skin lesions, especially near the lips and noses, and sensitivity to light. The best sources of riboflavin are liver, milk, meat, dark green vegetables, whole grains and enriched pasta, bread and mushrooms.
B3
Nicotinamide or vitamin B3, vitamin B complex whose structure reflects the amide of nicotinic acid or niacin, acts as coenzyme to release energy from nutrients. Also known as vitamin PP. The lack of niacin or nicotinic acid produces pellagra, whose first symptom is a rash resembling a sunburn wherever skin is exposed to sunlight Other symptoms arered and swollen tongue, diarrhea, mental confusion, irritability, and where the affected nervous system central depression and mental disorders. The best sources of niacin are liver, poultry, meat, canned salmon and tuna, whole or enriched cereals, peas (peas), dried beans and nuts. The body also makes niacin from the amino acid tryptophan. Have been used experimentally overdose of niacin in the treatment of schizophrenia, although no evidence has proven its effectiveness. In large amounts it reduces levels of blood cholesterol and has been widely used in the prevention and treatment of atherosclerosis. Large doses over prolonged periods can be harmful to the liver.
B6
Pyridoxine or vitamin B6 is necessary for the absorption and metabolism of amino acids. It also acts in the use of body fat and red blood cell formation. The failure of pyridoxine is characterized by abnormalities in skin, cracks in the corner of the lips, thicken tongue, convulsions, dizziness, nausea, anemia and kidney stones. The best sources of pyridoxine are whole grains (not enriched), cereals, bread, liver, avocado, spinach, green beans (green beans) and plantains. The amount of pyridoxine needed is proportional to the amount of protein consumed.
B12
Cobalamin or vitamin B12 is also known as cyanocobalamin, one of the most recently isolated vitamins and is necessary in minute quantities for the formation of nucleoproteins, proteins and red blood cells and nervous system function. The cobalamin deficiency is often due to the inability of the stomach to produce a glycoprotein (intrinsic factor) that helps absorb the vitamin. The result is pernicious anemia, with characteristic symptoms of poor production of red blood cells, defective synthesis of myelin (nerve sheath) and loss of epithelium (membranous cover) of the intestinal tract. Cobalamin is obtained only from animal sources: liver, kidney, meat, fish, eggs and milk. For the vegetarians are advised to take supplements of vitamin B12.
Other B vitamins
Folic acid or folacin, is a coenzyme necessary for the formation of structural proteins and hemoglobin, its failure in humans is very rare. Folic acid is effective in the treatment of certain anemias and psilosis. It is found in the viscera of animals, green leafy vegetables, legumes, nuts, whole grains and brewer’s yeast. Folic acid is lost in preserved foods at room atmosphere and during cooking. Unlike other water-soluble vitamins, folic acid is stored in the liver and need not ingest daily.
Pantothenic acid, another B vitamin, plays a yet undefined role in metabolism of protein, carbohydrates and fats. It abounds in many foods and is manufactured byintestinal bacteria.
Biotin, another B vitamin that is also synthesized by intestinal bacteria and is widely used in food, involved in fatty acid formation and release of energy from carbohydrates. Its failure is unknown in humans.
Vitamin C (ascorbic acid)
Vitamin C is important in the formation and maintenance of collagen, the protein that supports many structures and body that represents a very important role in building bones and teeth. It also promotes the absorption of iron from foods of plant origin. Scurvy is the classic manifestation of severe ascorbic acid. Your symptoms are due to the loss of the cementing action of collagen, and among them are bleeding, tooth loss and cellular changes in the bones of children. The claim that massive doses of ascorbic acid prevent colds and flu has not been obtained from carefully controlled experiments. However, other experiments have shown that ascorbic acid prevents the formation of nitrosamines, compounds that have caused tumors in animals of laboratory and perhaps occur in humans. Although unused ascorbic acid is rapidly eliminated in the urine, long and protracted doses can lead to the formation of bladder stones and kidney, interference with the effects of anticoagulants, destruction of vitamin B12 and calcium loss in bones. Sources of vitamin C include citrus fruits, fresh strawberries, grapefruit (grapefruit), pineapple and guava. Good vegetable sources are broccoli, Brussels sprouts, tomatoes, spinach, cabbage, green peppers, cabbage and turnips.
Vitamin D
It is necessary for normal bone formation and retention of calcium and phosphorus in the body. It also protects the teeth and bones against the effects of low calcium intake by making more effective use of calcium and phosphorus. Also called ‘solar vitamin’, vitamin D is obtained from egg yolk, liver, tuna and milk fortified with vitamin D. It is also manufactured in the body when sterols, found in many foods, traveling to the skin and receive the radiation of the sun for vitamin D insufficiency, or rickets, occurs rarely in tropical climates where there are abundant rays, but there was a time that was common among children in cities little sun before you start using this vitamin-enriched milk. Rickets is characterized by deformity of the rib cage and skull and bowed legs, all caused by poor absorption of calcium and phosphorus in the body. Because vitamin D is fat soluble and stored in the body, excessive drinking can cause vitamin poisoning, kidney damage, lethargy and loss of appetite.
Vitamin E
The role of vitamin E in the human body has not yet been clearly established, but is known to be an essential nutrient in over twenty vertebrate species. This vitamin is involved in the formation of red blood cells, muscles and other tissues and in preventing the oxidation of vitamin A and fats. It is found in vegetable oils, wheat germ, liver and green leafy vegetables. Although vitamin E is advisable popular for a variety of diseases, there is no substantial evidence to support these assertions. While stored in the body, it seems that the overdose of vitamin E have fewer toxic effects than other fat-soluble vitamins.
Vitamin K
Vitamin K is needed primarily for blood clotting. Supports the formation of prothrombin, an enzyme required for the production of fibrin in clotting. The richest sources of vitamin K are alfalfa and liver of fish, which are used to make preparations with concentrations of this vitamin. Dietary sources include all leafy green vegetables, egg yolk oil, soy or soy and liver. For a healthy adult, a normal diet and bacterial synthesis in the intestine is usually sufficient to supply the body of vitamin K and prothrombin. Digestive disturbances can cause poor absorption of vitamin K, and hence deficiencies in blood clotting.
Carbohydrates
The group of carbohydrate consists mainly of sugar, starch, dextrin, cellulose and glycogen, substances that form an important part of the diet of humans and many animals. The simplest are the simple sugars or monosaccharides, which contain an aldehyde or ketone group, the most important is glucose. Two monosaccharide molecules linked by an atom of oxygen, with the elimination of a water molecule, producing a disaccharide, the most important sucrose, lactose and maltose.
The starch and pectin, a cuajante agent, used in the preparation of food for man and livestock. Gum arabic is used in medicines demulcent. Agar, a component of some laxatives, finds use as a thickener in foods and as a medium for bacterial culture, and also in the preparation of materials adhesives, glue and emulsions. The hemicellulose is used to modify the paper during its manufacture. The dextran is a polysaccharide used in medicine as expanded volume of blood plasma to counteract acute shocks. Another carbohydrate, heparin sulfate, is a blood anticoagulant.
They bring a lot of energy in most human diets. Are burned during metabolism to produce energy, releasing carbon dioxide and water.
There are two types of carbohydrates: starches, which are mainly found in cereals, legumes and tubers, and sugars, which are present in vegetables and fruits. Carbohydrates are used by cells as glucose, the body’s main fuel.
The carbohydrates found in most of the nutrients are called complex carbohydrates such as unrefined cereals, tubers, fruits and vegetables, which also provide protein, vitamins, minerals and fats.
Fats
Fats are important in the diet as an energy source because they produce 9 kcal per gram. In developed countries, 40% or more of total energy consumption is typically from fat. It’s a higher percentage than what is considered desirable for health, excessive consumption of fat is associated with theobesity, heart disease and gall bladder and some cancers. Nutritional lines, therefore, recommend eating no more than 30% of energy through fat. In less developed countries, fat may contribute less than 15% of energy consumption level where it is difficult to eat enough to meet energy needs. Fat is also important for the absorption of fat soluble vitamins A, D, E and K. Much of the flavor of food is fat content.
To help people reduce fat intake, has created a variety of low fat products for partial or total replacement for butter and margarine (containing 80-82% fat) diet. Spreadable products are made with melted cream and vegetable oil and contain 72-75% fat, while the same low-fat products are mainly vegetable oils containing 60-70% fat, and can be used for kitchen like butter or margarine. Low (37-40%) and very low in fat (20-25%) contain milk fat and vegetable oils, and are not suitable for cooking. Those who have a very low fat content (5%) are produced using a substitute for fat as Simplesse, a modified protein, or Olestra (both are trademarks registered), a sugar polyester that is not digested.
Fats are divided into saturated and unsaturated, depending on whether the chemical bonds between carbon atoms of the molecules containing all atoms of hydrogen which can have (saturated) or have capacity for more atoms (unsaturated), due to the presence of double or triple bonds. Generally, saturated fats are solid at room temperature, unsaturated and polyunsaturated fats are liquid. Unsaturated fats can be converted into saturated fats by adding hydrogen atoms.
When added to the saturated solid fat diet increases the amount of cholesterol in the blood, but if the solid fats are replaced by fat or liquid unsaturated oils (in particular the polyunsaturated type), the amount of cholesterol decreases.
Although rarer than carbohydrates, fats produce more than twice the power. As a fuel
compact, fats are stored very well for use later in case of reduced intake of carbohydrates.
Avitaminosis
Lack of all vitamins.
This brings strong impact on enzyme activity, is particularly noticeable in the time of renutrición when demand suddenly exalted.
Particularly noteworthy is the lack of retinol, whose contribution remains to be the low protein intake. The provision of carotene, however, not offset, because the gut becomes little retinol, and hence falls crepuscular vision (less rhodopsin) recognizes the wrong colors, there Bitot’s spots and xerophthalmia (conjunctival atrophy dry eye ). In our environment, however, are not frequent the keratomalacia and corneal ulcer. As retinoic acid is also less, are less mucus to sebaceous secretions and reduces local skin immunity, that is exacerbated by the epithelial cell atrophy and increased keratinization, which occludes the hair follicles.
In theprimary malnutrition lack of thiamine blocks the conversion of pyruvic acid. In developing countries the most obvious manifestation is beriberi. Thiamine is also required to metabolize branched aminoáicidos.
The lack of riboflavin flavoprotein affecting synthesis necessary for the deamlnación, fatty acid oxidation and respiratory chain. This is compounded by the lack of input njacina also acts as electron carrier and can not be offset by metaboljsmo tryptophan as an essential amino acid and its contribution is diminished. Lack of pyridoxine compromise the functioning of a large number of enzymatic reactions. In contrast is very common folate deficiency, which are essential for the synthesis of the nuclei of all cells, which can be witnessed to by the diagnosis of macrocytic anemia. CobaIamina deficiency is compensated by strong hepatic reserves by diffusion and absorption by the low contribution of intrinsic factor.
Menadione deficiency is compensated by the intestinal bacterial synthesis, but in the newborn there is little contribution to lactation failure that maternal flora and there is a tendency to bleed.
One hypothesis to explain the action of tocopherols postulates that interacts with the phytyl chain unsaturated fatty acid membranes.
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Ecology-science studia k l ecosistma. / / Ecosistma – You dntro natural biome dl l k-space includes physical and physical fctors kl ls cractrizan (biotope) and the living creatures cnjunt d ls mong rlacions stablcidas ells (biocnosis) / / fcotrs abiotic – ks cnjunt d fctores place in a life ecosistma k d l ls prmitn agencies – climate – characterized the state of the atmosphere on a punt d dtrminado the land suprficie dl (T ª, humdad, precipitation, wind, light) / / soil factors – prmitn dscribir ls dl cractristicas sbre infrmacion soil and its structura prprcionan and cmposicion (texture, development – not evolucionads (single parent rock), evolved: distinguished layers or horiznts: Hd-rock mother, Hc-altered bedrock, Ha-saline od prcipitacion, Ha-x frmad living dscomposicion d (H arable) and HA0) composition hydrogen-No: acid 7, neutral = 7, color –k degree of organic matter has the floor (white = muxas salts, organic matter = mxa dark), porosity = a more porous mayr dsarrollan vegetals s) / / water / fctors k factors characterize the aquatic environment: T ª, O2, salinity, pressure light / / adaptcions the MDIO acuatico – 1-locomotion (frma hydrodynamics, rspiracion cutaneous or gill), 2 – light, 3 – humdad.: ind xerophytic (ind. looking for scarce humdad k), mesophiles (k ind humdad buska media) hydrophilic (bskan mxa humdad k ind) / / adaptcions the ground – you dsarrollan ls arthropods, molluscs not. ks mobile ground-cap ncuentra more secluded in the lithosphere, ecological succession – succession d living in one of the LGAR and trnfrmacion means k can sbrevivir / / adptacions the air – alas, poko weight / / Biotic – fctoresk cndicionan ecosystem related stan k k ls beings living in: intraspecific relations – relations of cooperation sn: R.familiares (maintaining specie = playback), R. gregarious (migration) R.sociales (mntnimint d 1 d group ind mdiant work put one rparticion dl) and R. Colonial (dfens dl group, no dl rprticion work. xa ind join dfnsa stablish a barrier d); relacions interspecificas-antagonistic – rlaciones d 2 in the k 1 ind out prjudicada specie (dpredacion – reguln the poblcions, parasitism — ay a parasite and a host-and competition-when 2 different species cnvivn in 1 spot), symbiosis (2 mong rlacion ls lk sp 2 species get 1 benefit-if not die-junts stn), mutualism (2 sp rlacion mong if one does not die another dsaparece l), commensalism (2 sp rlcion etween k 1 ls feeds aya k dl another without prejudice or other benefit xa ind), InKiLiNo (sn ls akells in kuala 1 single, gets the bneficio mientrs another is indifrnte. rlacion sta sta bsada in the utilization d una structura created another specie x) tanatrocresis (frgments d ind muerts used his abitaculo xa) and Foresi (relation etween 1 sp vegtal and other animals. vgtal l used the animal sp xa trnsprtar pollen or fruit) / /biomes – large xtiend xa ks ecosistma physical spacing dtrminado x 1as cndicions mdioambientles specifica. ay 3 types: trrestre (the 1st distribution is living dpndiendo d ls d ls climatic cndicions altitude, a point dstncia d rspecto dl level sea, latitude, distncia d 1 point rspecto to Ecuador. cndcions climticas: T ª, prcipitcion, grade d evapracion.) marine (depth (pressure, light, T th), sixth salinity and marine corrients. divrsidad implies 1 large) and freshwater (k trreno x the water runs, dixibia the trreno and has its characteristics, high current (low Cudal, high vlocidd (erosion and high O2)) middle (high flow, average speed, bends), low current (high flow, low vlocidad). has low diversity. / / types biomes – d as a function of latitude: polar (in high latituds: T ª cold in ls limits 2 stacion: cold or very cold winter and summer “soft”) high mntaña areas (cract. similars to znas number of exemplary ratings: 2 divisions: tundra (d thawing top layer and a new formation d layer (permafrost) veg: mosses, likened, in herbacieos cn root hair; animals flies moskits, migratory birds, mammals (adaptations to low T th)) and Taiga (T º floor and snow in abundance, veg: conifers; animals: mammals (wolf, lynx …) kaducifolio Bosk (rain tdo stacions year and 2 marked (warm and cold) veg: arbls deciduous; animals: avs migratory mammals (bear, squirrel, fox …) laurel (T º tdo tmplada or warm year, regular rainfall, high mean humdad k), desert (very skas rains and T ª very XTREME cmo pka animal life both plant trees absence d), savanna (rainfall Scase and T º high vgtals: herbaceous and shrub disprsos: animals: large abundncia d animls corrdores) Prads and Stepan (rain Scase and T ª Xtreme, at least k aunk dsiert, vegetals: herbs, animals: herbivores) bske mditerraneo (Scase and irrgulars rain, 4 and stacions cn verans calursos secs, invierns suavs, veg: arbles and evergreen shrubs and hard; animals: conejs, squirrels, lagarts …) jungle (abudnts rains, high Durnten T tdo th year, veg: evergreen plants, animals: large divrsidad) / / marine biome – is dividn into 3 groups: benthic (bottom and puedn sr ndadors, xcavadrs, fixed and rptants), Plankton (flotna in water and can mvr horizntalmnt x ls vrticlmnt and marine corrients. frman plankton, cmpuesto x fitoplncton and zooplankton.) and nekton (s dsplazan x water x environment is, tman mayr k sn ls d above) / /ls d ls ecosistmas dynamic changes in dl ecosistmas s BSAN ls dl matter cycles and energy flow d (n is maintained in the ecosistma). dl discurrn to TRVS ecosistma x ls cDNA web. They will provide the stage ecosistma d llgand a climax (stable stage), if destroyed s produces a sequence (trnsformcion d 1 ecosistma) / / food web – series living ks d d other almintan us. / / Food web – series d chains between rlacionan k if H productivdad-1 ecosistma s + quant + biomass tnga effective and less time to produce it later
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Gastrointestinal: Salmonella, Escherichia coli, Shigella, Giardia and feared the amoebas. . Respiratory: influenza, asthma, bronchitis, pharyngitis, pneumonia. Fungal. These are diseases caused by fungi, which occur in waste, and affect the skin, hair and nails. Nerve. These diseases are mainly at people who are frequently exposed to noise,