Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. Chemically Chemistry is the science of matter and the changes it undergoes. The science of matter is also addressed by physics, but while physics takes a more general and fundamental approach, chemistry is more specialized, being concerned with the composition, behavior, structure, and properties of matter, as well as the changes it undergoes during chemical, fats are generally triesters Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group, and most commonly from carboxylic acids and alcohols. Basically, esters are of glycerol Glycerol is an organic compound, also called glycerin or glycerine. It is a colourless, odourless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol substructure is a central component of many and fatty acids In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. The most occurring natural fatty acids have an even number of carbon atoms because their biosynthesis involves acetyl-CoA, a coenzyme carrying a two-carbon-atom group (see fatty acid synthesis). Fats may be either solid Solid is one of the major states of matter. It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a gas does. The atoms in a solid are tightly bound to each other, or liquid Liquid is one of the three classical states of matter. Like a gas, a liquid is able to flow and take the shape of a container, but, like a solid, it resists compression. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, at room temperature Room temperature is a common term to denote a certain temperature within enclosed space to which humans are accustomed. Room temperature is thus often indicated by general human comfort, with the common range of 20 °C to 25 °C (77 °F), though climate may acclimatize people to higher or lower temperatures, depending on their structure and composition. Although the words "oils An oil is any substance that is liquid at ambient temperatures and is hydrophobic but soluble in organic solvents. Oils have a high carbon and hydrogen content and are nonpolar substances. The general definition above includes compound classes with, and uses, including vegetable oils, petrochemical oils, and volatile essential oils. All oils can", "fats", and "lipids Lipids are a broad group of naturally occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling molecules" are all used to refer to fats, "oils" is usually used to refer to fats that are liquids at normal room temperature, while "fats" is usually used to refer to fats that are solids at normal room temperature. "Lipids" is used to refer to both liquid and solid fats, along with other related substances. The word "oil" is used for any substance that does not mix with water and has a greasy feel, such as petroleum Petroleum or crude oil is a naturally occurring, toxic, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights, and other organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling. It is refined and separated, most easily by (or crude oil) and heating oil Heating oil, or oil heat, is a low viscosity, flammable liquid petroleum product used as a fuel for furnaces or boilers in buildings, regardless of its chemical structure.^[1]

Fats form a category of lipid Lipids are a broad group of naturally occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling molecules, distinguished from other lipids by their chemical structure A chemical structure includes molecular geometry, electronic structure and crystal structure of a chemical compound. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as diatomic oxygen or nitrogen molecules, to and physical properties. This category of molecules is important for many forms of life, serving both structural and metabolic functions. They are an important part of the diet In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management reasons . Although humans are omnivores, each culture of most heterotrophs A heterotroph is an organism that uses organic carbon for growth by consuming other organisms. This contrasts with autotrophs, such as plants, which can directly use sources of energy such as light to produce organic substrates from carbon dioxide (including humans). Fats or lipids are broken down in the body by enzymes called lipases A 'lipase' is a water-soluble enzyme that catalyzes the hydrolysis of ester chemical bonds in water-insoluble lipid substrates. Lipases thus comprises a subclass of the esterases produced in the pancreas The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as an exocrine gland, secreting pancreatic juice containing digestive enzymes that pass to the small intestine. These enzymes help to further.

Examples of edible animal fats are lard Lard is pig fat in both its rendered and unrendered forms. Lard was commonly used in many cuisines as a cooking fat or shortening, or as a spread similar to butter. Its use in contemporary cuisine has diminished because of health concerns posed by its saturated-fat content and its often negative image; however, many contemporary cooks and bakers (pig fat), fish oil Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid , and docosahexaenoic acid (DHA), precursors to eicosanoids that are known to reduce inflammation throughout the body, and have many health benefits. Fish do not actually produce omega-3 fatty acids, but instead accumulate them, and butter Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying. Butter consists of butterfat, water and milk proteins or ghee Ghee is a class of clarified butter that originated in South Asia, and is commonly used in South Asian (Indian, Bangladeshi and Pakistani), North African (Egyptian and Berber) and Horn African cuisine (Somali, Ethiopian and Eritrean). They are obtained from fats in the milk, meat and under the skin of the animal. Examples of edible plant fats are peanut, soya bean, sunflower, sesame, coconut, olive, and vegetable oils. Margarine Margarine , as a generic term, can indicate any of a wide range of butter substitutes. In many parts of the world, the market share of margarine and spreads has overtaken that of butter. Margarine is an ingredient in the preparation of many foods and, in recipes and colloquially, is sometimes called oleo, short for oleomargarine and vegetable shortening Shortening is a semisolid fat used in food preparation, especially baked goods, and is so called because it promotes a "short" or crumbly texture . Shortening is fat or lard from an animal or vegetable. The term "shortening" can be used more broadly to apply to any fat that is used for baking and which is solid at room, which can be derived from the above oils, are used mainly for baking. These examples of fats can be categorized into saturated fats Saturated fat is fat that consists of triglycerides containing only saturated fatty acid radicals. There are several kinds of naturally occurring saturated fatty acids, which differ by the number of carbon atoms, ranging from 3 carbons to 36 (Hexatriacontanoic acid). Saturated fatty acids have no double bonds between the carbon atoms of the fatty and unsaturated fats An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fat molecule is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. Where double bonds are formed, hydrogen atoms are eliminated. Thus, a saturated fat has no double bonds,.

Chemical structure

There are many different kinds of fats, but each is a variation on the same chemical structure. All fats consist of fatty acids In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. The most occurring natural fatty acids have an even number of carbon atoms because their biosynthesis involves acetyl-CoA, a coenzyme carrying a two-carbon-atom group (see fatty acid synthesis) (chains of carbon Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with 12C and 13C being stable, while 14C is radioactive, decaying with a half-life of and hydrogen Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of 1.00794 u (1.007825 u for Hydrogen-1), hydrogen is the lightest and most abundant chemical element, constituting roughly 75 % of the Universe's elemental mass. Stars in the main sequence are mainly composed of hydrogen in its atoms, with a carboxylic acid Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. A carboxyl group is a functional group consisting of a carbonyl and a hydroxyl, which has the formula -C(=O)OH, usually written -COOH or -CO2H. Carboxylic acids are Brønsted-Lowry acids — they are proton donors. Salts and anions of carboxylic acids group at one end) bonded to a backbone structure, often glycerol Glycerol is an organic compound, also called glycerin or glycerine. It is a colourless, odourless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydrophilic hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol substructure is a central component of many (a "backbone" of carbon, hydrogen, and oxygen). Chemically, this is a triester Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group, and most commonly from carboxylic acids and alcohols. Basically, esters are of glycerol, an ester being the molecule formed from the reaction of the carboxylic acid and an organic alcohol. As a simple visual illustration, if the kinks and angles Molecular geometry or molecular structure is the three-dimensional arrangement of the atoms that constitute a molecule. It determines several properties of a substance including its reactivity, polarity, phase of matter, color, magnetism, and biological activity of these chains were straightened out, the molecule would have the shape of a capital letter E. The fatty acids would each be a horizontal line; the glycerol "backbone" would be the vertical line that joins the horizontal lines. Fats therefore have "ester" bonds A chemical bond is an attraction between atoms or molecules and allows the formation of chemical compounds, which contain two or more atoms. A chemical bond is the attraction caused by the electromagnetic force between opposing charges, either between electrons and nuclei, or as the result of a dipole attraction. The strength of bonds varies.

The properties of any specific fat molecule depend on the particular fatty acids that constitute it. Different fatty acids are composed of different numbers of carbon and hydrogen atoms. The carbon atoms, each bonded to two neighboring carbon atoms, form a zigzagging chain; the more carbon atoms there are in any fatty acid, the longer its chain will be. Fatty acids with long chains are more susceptible to intermolecular forces of attraction (in this case, van der Waals forces In physical chemistry, the van der Waals force , named after Dutch scientist Johannes Diderik van der Waals, is the attractive or repulsive force between molecules (or between parts of the same molecule) other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral molecules. The term includes:), raising its melting point The melting point of a solid is the temperature at which the vapor pressure of the solid and the liquid are equal. At the melting point the solid and liquid phase exist in equilibrium. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point. Because of the ability of some substances to. Long chains also yield more energy In physics, energy is a quantity that is often understood as the ability to perform work. This quantity can be assigned to any particle, object, or system of objects as a consequence of its physical state per molecule when metabolized.

Saturated and unsaturated

A fat's constituent fatty acids may also differ in the number of hydrogen atoms that are bonded to the chain of carbon atoms. Each carbon atom is typically bonded to two hydrogen atoms. When a fatty acid has this typical arrangement, it is called "saturated" Saturated fat is fat that consists of triglycerides containing only saturated fatty acid radicals. There are several kinds of naturally occurring saturated fatty acids, which differ by the number of carbon atoms, ranging from 3 carbons to 36 (Hexatriacontanoic acid). Saturated fatty acids have no double bonds between the carbon atoms of the fatty, because the carbon atoms are saturated with hydrogen; meaning they are bonded A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, and other covalent bonds. In short, the attraction-to-repulsion stability that forms between atoms when they share electrons is known as covalent bonding to as many hydrogens as possible. In other fats, a carbon atom may instead bond to only one other hydrogen atom, and have a double bond A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, and other covalent bonds. In short, the attraction-to-repulsion stability that forms between atoms when they share electrons is known as covalent bonding to a neighboring carbon atom. This results in an "unsaturated" fatty acid. More specifically, it would be a monounsaturated fatty acid, whereas, a polyunsaturated fatty acid These fatty acids have 2 or more cis double bonds that are separated from each other by a single methylene group would be a fatty acid with more than one double bond. Saturated and unsaturated fats differ in their energy content and melting point. Since an unsaturated fat contains fewer carbon-hydrogen bonds than a saturated fat with the same number of carbon atoms, unsaturated fats will yield slightly less energy during metabolism than saturated fats with the same number of carbon atoms. Saturated fats can stack themselves in a closely packed arrangement, so they can freeze easily and are typically solid at room temperature. But the rigid double bond in an unsaturated fat fundamentally changes the chemistry of the fat.

Trans fatty acids

There are two ways the double bond may be arranged: the isomer with both parts of the chain on the same side of the double bond (the cis-isomer), or the isomer with the parts of the chain on opposite sides of the double bond (the trans In organic chemistry, cis-trans isomerism or geometric isomerism or configuration isomerism or E-Z isomerism is a form of stereoisomerism describing the orientation of functional groups within a molecule. In general, such isomers contain double bonds, which cannot rotate, but they can also arise from ring structures, wherein the rotation of bonds-isomer). Most trans-isomer fats (commonly called trans fats Trans fat is the common name for unsaturated fat with trans-isomer fatty acid. Trans fats may be monounsaturated or polyunsaturated but never saturated) are commercially produced rather than naturally occurring. The cis-isomer introduces a kink into the molecule that prevents the fats from stacking efficiently as in the case of fats with saturated chains. This decreases intermolecular forces between the fat molecules, making it more difficult for unsaturated cis-fats to freeze; they are typically liquid at room temperature. Trans fats may still stack like saturated fats, and are not as susceptible to metabolization as other fats.

Trans fats may significantly increase the risk of coronary heart disease Coronary disease refers to the failure of coronary circulation to supply adequate circulation to cardiac muscle and surrounding tissue. It is already the most common form of disease affecting the heart and an important cause of premature death in Europe, the Baltic states, Russia, North and South America, Australia and New Zealand. It has been.^[2]

Importance for living organisms

Vitamins A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on the circumstances and the particular organism. For A Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal. This molecule is absolutely necessary for both scotopic and color vision. In another version the vitamin is necessary for the function of the reproductive systems of both male and female mammals. Vitamin A also, D Vitamin D is a group of fat-soluble secosteroids, the two major physiologically relevant forms of which are vitamin D2 and vitamin D3 (cholecalciferol). Vitamin D without a subscript refers to either D2 or D3 or both. Vitamin D3 is produced in the skin of vertebrates after exposure to ultraviolet B light from the sun or artificial sources, and, E Vitamin E is a generic term for tocopherols and tocotrienols. Vitamin E is a family of α-, β-, γ-, and δ- tocopherols and corresponding four tocotrienols. Vitamin E is a fat-soluble antioxidant that stops the production of reactive oxygen species formed when fat undergoes oxidation. Of these, α-tocopherol (also written as alpha-tocopherol), and K Vitamin K denotes a group of lipophilic, hydrophobic vitamins that are needed for the posttranslational modification of certain proteins, mostly required for blood coagulation, but also a number of other proteins that chelate calcium ions and are involved in bone and other tissue metabolism. They are 2-methyl-1,4-naphthoquinone derivatives are fat-soluble, meaning they can only be digested, absorbed, and transported in conjunction with fats. Fats are also sources of essential fatty acids Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest for good health because the body requires them but can't make them from other food components. The term refers to fatty acids required for biological processes, and not those that only act as fuel, an important dietary requirement.

Fats play a vital role in maintaining healthy skin and hair, insulating body organs against shock, maintaining body temperature, and promoting healthy cell function.

Fats also serve as energy stores for the body, containing about 37.8 kilo joules (9 Calories) per gram of fat^[3]. They are broken down in the body to release glycerol and free fatty acids. The glycerol can be converted to glucose by the liver and thus used as a source of energy.

Fat also serves as a useful buffer towards a host of diseases. When a particular substance, whether chemical or biotic—reaches unsafe levels in the bloodstream, the body can effectively dilute—or at least maintain equilibrium of—the offending substances by storing it in new fat tissue. This helps to protect vital organs, until such time as the offending substances can be metabolized and/or removed from the body by such means as excretion, urination, accidental or intentional bloodletting, sebum excretion, and hair growth.

While it is nearly impossible to remove fat completely from the diet, it would be unhealthy to do so. Some fatty acids are essential nutrients, meaning that they can't be produced in the body from other compounds and need to be consumed in small amounts. All other fats required by the body are non-essential and can be produced in the body from other compounds.

Adipose tissue

In animals, adipose, or fatty tissue is the body's means of storing metabolic energy over extended periods of time. Depending on current physiological conditions, adipocytes store fat derived from the diet and liver metabolism or degrade stored fat to supply fatty acids and glycerol to the circulation. These metabolic activities are regulated by several hormones (i.e., insulin, glucagon and epinephrine). The location of the tissue determines its metabolic profile: "Visceral fat" is located within the abdominal wall (i.e., beneath the wall of abdominal muscle) whereas "subcutaneous fat" is located beneath the skin (and includes fat that is located in the abdominal area beneath the skin but above the abdominal muscle wall). Visceral fat was recently discovered to be a significant producer of signaling chemicals (i.e., hormones), among which are several which are involved in inflammatory tissue responses. One of these is resistin which has been linked to obesity, insulin resistance, and Type 2 diabetes. This latter result is currently controversial, and there have been reputable studies supporting all sides on the issue.

See also

References

1. ^ Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall. ISBN 0-13-981176-1. OCLC 32308337.
2. ^ Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC (13 April 2006). "Trans Fatty Acids and Cardiovascular Disease". New England Journal of Medicine 354 (15): 1601–1613. doi:10.1056/NEJMra054035. PMID 16611951. PMID 16611951
3. ^ NASA Energy

• Donatelle, Rebecca J. (2005). Health, the Basics (6th ed.). San Francisco: Pearson Education, Inc. ISBN 0131206877. OCLC 51801859.

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