Nutrition is the strategy adopted by an organism to obtain the chemicals it needs to live, grow, and reproduce. The term is also applied to the science of food, and its effect on human and animal life, health, and disease.
Nutrition involves the study of the basic nutrients required to sustain life, their bio-availability in foods and overall diet, and the effects upon them of cooking and storage. It is also concerned with dietary deficiency diseases. There are six classes of nutrients: water, carbohydrates, proteins, fats, vitamins, and minerals. Water is involved in nearly every body process. Animals and humans will succumb to water deprivation sooner than to starvation. Carbohydrates are composed of carbon, hydrogen and oxygen. The major groups are starches, sugars, and cellulose and related material (or ' roughage'). The prime function of the carbohydrates is to provide energy for the body; they also serve as efficient sources of glucose, which the body requires for brain functioning, utilisation of foods, maintenance of body temperature. Roughage includes the stiff structural materials of vegetables, fruits, and cereal products. Proteins are made up of smaller units, amino acids. The primary function of dietary protein is to provide the amino acids
required for growth and maintenance of body tissues. Both vegetable and animal foods are protein sources. Fats serve as concentrated sources of energy, and protect vital organs such as the kidneys and skeleton. Saturated fats derive primarily from animal sources; unsaturated fats from vegetable sources such as nuts and seeds. Vitamins are essential for normal growth, and are either fat-soluble or water-soluble. Fat-soluble vitamins include A, essential to the maintenance of mucous membranes, particularly the conjunctiva of the eyes; D, important to the absorption of calcium; E, an antioxidant; and K, which aids blood clotting. Water-soluble vitamins are the B complex, essential to metabolic reactions, and C, for maintaining connective tissue and cell functioning. Minerals are vital to normal development; calcium and iron are particularly important as they are required in relatively large amounts. Minerals required by the body in trace amounts include chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc. Research Nutrition
Budding yeasts are true fungi of the phylum Ascomycetes, class Hemiascomycetes. The true yeasts comprise the family Saccharomycetes, which has but one genusSaccharomyces, but includes at least ten species. The classification of yeasts is a specialized field using cell, ascospore, and colony characteristics for distinguishing genera, and physiological characteristics - particularly the ability to ferment individual sugars - to identify species. Yeasts are heterotrophic, lack chlorophyll, and are characterized by a wide dispersion of natural habitats. Common on plant leaves and flowers, yeasts are also found on the skin surfaces and in the intestinal tracts of warm-blooded animals, where they may live symbiotically or as parasites. In women, who are pregnant or taking antibiotics, an infection of the vagina and vulva caused by a yeast like fungus Candida albicans, is common. Yeasts are also found in soil and saltwater, where they contribute to the decomposition of plant and algal matter.
Yeasts multiply as single cells that divide by budding or direct division, or they may grow as simple irregular filaments. In sexual reproduction most yeasts form asci, which contain up to eight haploid ascospores. These ascospores may fuse with adjoining nuclei and multiply through vegetative division or, as with certain yeasts, fuse with other ascospores. The most well-known and commercially significant yeasts are the related species and strains of Saccharomyces cerevisiae. These organisms have long been utilized to ferment the sugars of rice, wheat, barley, and corn to produce alcoholic beverages and in the baking industry to expand, or raise, dough. Saccharomyces cerevisiae is commonly used as baker's yeast and for some types of fermentation. Yeast is often taken as a vitamin supplement because it is 50 percent protein and is a rich source of B vitamins, niacin, and folic acid. The yeast's function in baking is to ferment sugarspresent in the flour or added to the dough. This fermentation gives off carbon dioxide and ethanol. The carbon dioxide is trapped within tiny bubbles and results in the dough expanding, or rising. Research Yeast
Haemolymph is the circulatory fluid of those molluscs and insects that have an 'open' circulatory system.
Haemolymph contains water, amino acids, sugars, salts, and white cells like those of blood. The fluid is circulated by a pulsating heart. Its main functions are to transport digestive and excretory products around the body. In molluscs, it also transports oxygen and carbon dioxide. Research Haemolymph
Plasma, made of about 92% water, is the blood's solvent. It is the liquid part of the blood, or blood minus cells, containing proteins, minerals, and salts. Its main components are the three proteins: albumin, globulins, and fibrinogen, all of which are manufactured by the liver. These three proteins circulate in plasma and act as carriers for small molecules. Salts, minerals, sugars, fats, and proteins, all important nutrients, are transported through plasma. All of the chemicals needed by cells to stay alive are brought to them by the blood. At the same time, bicarbonates in the plasma act as a filter to remove poisonous waste to the kidneys. Albumin, the most plentiful, is similar to egg whites and gives blood its gummy texture. The globulins, three in number: alpha, beta, and gamma, transport certain proteins. They number half the albumin proteins found in plasma. Gamma globulins are the antibodies of the blood, giving immunity to disease. Only 3% of plasma is made up of fibrinogen. It is an important link in the chain of reactions that leads to blood clotting. It forms a web of fine protein fibres that bindblood cells together, creating a bridge over which injured tissue can rebuild itself while blood continues to flow underneath. Research Plasma
Absolute configuration is a way of denoting the absolute structure of an optical isomer. Two conventions are in use: The D-L convention relates the structure of the molecule to some reference molecule. In the case of sugars and similar compounds, the dextrorotatory form of glyceraldehyde was used. The rule is as follows. Write the structure of this molecule down with the asymmetric carbon in the centre, the -CHO group at the top, the -OH on the right, the -CH2OH at the bottom, and the -H on the left. Now imagine that the central carbonatom is at the centre of a tetrahedron with the four groups at the corners and that the -H and -OH come out of the paper and the -CHO and -CH2OH groups go into the paper. The resulting three-dimensional structure was taken to be that of d-glyceraldehyde and called D-glyceraldehyde. Any compound that contains an asymmetric carbonatom having this configuration belongs to the D-series. One having the opposite configuration belongs to the L-series. It is important to note that the prefixes D- and L- do not stand for dextrorotatory and laevorotatory (they are not the same as d- and l-).
In fact the arbitrary configuration assigned to D-glyceraldehyde is now known to be the correct one for the dextrorotatory form, although this was not known at the time. However, all D-compounds are not dextrorotatory. For instance, the acid obtained by oxidizing the -CHO group of glyceraldehyde is glyceric acid (1,2-dihydroxypropanoic acid). By convention, this belongs to the D-series, but it is in fact laevorotatory; i.e. its name can be written as D-glyceric acid or l-glyceric acid. To avoid confusion it is better to use + (for dextrorotatory) and - (for laevorotatory), as in D-(+)-glyceraldehyde and D-(-)-glyceric acid. The D-L convention can also be used with alpha amino acids. In this case the molecule is imagined as being viewed along the H-C bond between the hydrogen and the asymmetric carbonatom. If the clockwise order of the other three groups is -COOH, -R, -NH2, the amino acid belongs to the D-series; otherwise it belongs to the L-series. This is known as the CORN rule.
The R-S convention is a convention based on priority of groups attached to the chiral carbonatom. The order of priority is I, Br, Cl, SO3H, OCOCH3, OCH3, OH, NO2, NH2, COOCH3, CONH2, COCH3, CHO, CH2OH, C6H5, C2H5, CH3, H, with hydrogen being the lowest. The molecule is viewed with the group of lowest priority behind the chiral atom. If the clockwise arrangement of the other three groups is in descending priority, the compound belongs to the R-series; if the descending order is anticlockwise it is in the S-series. D-(+)-glyceraldehyde is R-(+)-glyceraldehyde. Research Absolute Configuration
Animal Chemistry is the department of organicchemistry which investigates the composition of the fluids and the solids of animals, and the chemical action that takes place in animal bodies. There are four elements, sometimes distinctively named organic elements, which are invariably found in living bodies, that is carbon, hydrogen, oxygen, and nitrogen. To these may be added, as frequent constituents of the human body, sulphur, phosphorus, lime, sodium, potassium, chlorine, and iron.
The four organic elements are found in all the fluids and solids of the body. Sulphur occurs in blood and in many of the secretions. Phosphorus is also common, being found in nerves, in the teeth, and in fluids. Chlorine occurs almost universally throughout the body; lime is found in bone, in the teeth, and in the secretions; iron occurs in the blood, in urine, and in bile; and sodium, like chlorine, is of almost universal occurrence. Potassium occurs in muscles, in nerves, and in the blood-corpuscles. Minute quantities of copper, silicon, manganese, lead, and lithium are also found in the human body.
The compounds formed in the human organism are divisible into the organic and inorganic. The most frequent of the latter is water, of which two-thirds (by weight) of the body are composed. The organic compounds may, like the foods from which they are formed, be divided into the nitrogenous and non-nitrogenous. Of the former the chief are albumen (found in blood, lymph, and chyle), casein (found in milk), myosin (in muscle), gelatin (obtained from bone), and others. The non-nitrogeneous compounds are represented by organic acids, such as formic, acetic, butyric, stearic, etc by animal starches, sugars; and by fats and oils, as stearin and olein. Research Animal Chemistry
Carbohydrate is one of the three main classes of foods and a source of energy.
Carbohydrates are mainly sugars and starches that the body breaks down into glucose. The body also uses carbohydrates to make the substance glycogen that is stored in the liver and muscles for future use. If the body does not have enough insulin or cannot use the insulin it has, then the body will not be able to use carbohydrates for energy the way it should. This condition is called diabetes. Research Carbohydrate
Cellulose is a generic name for substances of which the cell-membranes of plants are composed. They are carbohydrates allied to starch, and when heated with dilate acid yield sugars. Ordinary cellulose has been found in a few invertebrate animals. Wood-pulp for paper making mostly consists of cellulose, so also does gun-cotton. Research Cellulose
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Research Nutrition
