LIPID COMPOUNDS IN LIFE

Lipid is one of a group of organic compounds found in plants, animals, or humans and are very useful for human life. Lipid compounds do not have a formula similar structure or similar. Kimi properties and biological functions also vary.
Subcutaneous tissue around the abdomen, the fat tissue around the kidneys contain a lot of lipids, especially fatty approximately 90%, in brain tissue lipid atal the eggs are about the size of 7.5 to 30%.
Karakteriktik and Lipid Structure
 Physical Characteristics
The term lipids include fats, oils and related compounds are not soluble in water and oily to the touch. Some lipid foods, butter, margarine, or cooking oil can be easily identified as fat. Other foods that may seem to consist of mostly carbohydrates (bread types) or protein (cow pie) often contain a lot of fat. We refer to this as the hidden fat.

 Chemical Characteristics
Chemical name for fats and related compounds are fat lipids. Lipids are organic compounds consisting of a carbon chain as a "basic framework", with the hydrogen and oxygen atoms and other radicals or groups tertikat other elements. Fatty acids and related compounds are lipids that are important in human nutrition. Lipids have a general similarity with carbohydrates. Same chemical elements that make up carbohydrates - carbon, hydrogen, and oxygen - also form fatty acids. However, carbohydrates and lipids have two important differences as follows:
 Lipid more complex structure, with more carbon atoms (C) and hydrogen (H) and fewer oxygen atoms (O).
 structural units of lipids is common fatty acids, while the structural units of carbohydrates are simple sugars. First we will look at the typical characteristics of fatty acids - saturation, chain length, and essentiality - before focusing on the properties of lipid (triglycerides) are composed of fatty acids. (Junaidi, 2012)
 LIPID STRUCTURE
Lipid-based compound is defined as fatty acids or fatty acid-like molecules such as alcohol or spingosin.





Figure 1 Structure of Lipids
The structures of some common lipids. At the top is oleic acid and cholesterol. The structure of the center is composed of a chain triglycerides oleoil, stearoyl, and palmitoyl glycerol attached to the frame. At the bottom is the common phospholipid, fosfatidikolina. Characteristics that are common in all the lipid content of hydro-carbon is derived from acetate polymerization followed by reduction of the chain as soon as the chain is formed.
Lipid function is:
• As a structural constituent of cell membranes
• In this lipid acts as a barrier to cells and regulate the flow of materials
• As a backup energy
• Lipids are stored as adipose tissue
• As hormaon and vitamin
• Hormone regulate communication between cells, while vitamin helps the regulation of biological processes.
 Gliserolipid
Gliserolipid is a lipid-containing glycerol in which the hydroxyl groups have been substituted. Gliserolipid are the most abundant lipids in animals. Gliserolipid substitutes composed of glycerol mono-, di-, and tri-, the most famous are the fatty acid esters of glycerol (triacylglycerol), also known as triglycerides. Within these compounds, the three hydroxyl groups esterified glycerol respectively, usually by different fatty acids. Because it serves as food reserves, lipid is present in most of the fat reserves in animal tissues. Triacylglycerol hydrolysis of the ester bond and release of glycerol and fatty acids from adipose tissue are called "fat mobilization."
Another gliserolipid glikosilgliserol Subclass, which is characterized by the presence of one or more monosaccharide residues attached to glycerol via a glycosidic bond. Examples of structures in this category are digalaktosildiasilgliserol were found in the membrane of plant and seminolipid of mammalian sperm cells.
Glycerides are esters of fatty acids and alcohols with similar functional tigagugus called glycerol (IUPAC name, 1,2,3-propantriol). Since glycerol has three functional groups alcohols, fatty acids will react to make three ester groups at once. Glycerides with three fatty acid ester group called triglycerides. Types of fatty acids attached to the third group often did not come from the same class of fatty acids.

 Phospholipids
(Glisero) phospholipids (English: phospholipids, phosphoglycerides, glycerophospholipid) is very similar to triglycerides with some exceptions. Phospholipids are formed from glycerol (IUPAC name, 1,2,3-propantriol) with two alcohol groups that form the fatty acid ester group (can be from different classes), and an alcohol group to form phosphoric acid ester group.
Gliserofosfolipid, also referred to as phospholipids, there are quite a lot in nature and are key components dwilapis lipd cells, and are involved in the metabolism and signal communication between cells. Neural tissue including the brain, contains enough gliserofosfolipid. Changes in the composition of these substances can result in various neurological disorders.
Examples gliserofosfolipid found in biological membranes are fosfatidilkolina (also known as PC, GPCho, or lecithin), fosfatidiletanolamina (PE or GPEtn), and fosfatidilserina (PS or GPSer). In addition to acting as the primary component of cell membranes and a commitment to the protein intra-and antarseluler, some gliserofosfolipid in eukaryotic cells, such as phosphatidylinositol and fosfatidat acid is a precursor, or second messenger itself is derived from the membrane. Typically, one or both of these hydroxyl groups acylated with long-chain fatty acids, meskit gliserofosfolipid there are bound to alkyl and 1Z-alkenyl (plasmalogen). There are also variants dialkileter on arkaebakteria.
Gliserofosfolipid can be divided according to the nature of the polar head groups at the sn-3 position of the glycerol backbone in eukaryotes and eubakteria, or sn-1 position in the case of archaea.
Because the phosphoric acid ester group still has a free valence bond, usually with alcohol to form the ester group, such as amino alcohols kolina, ethanolamine and serine. Phospholipids are the major component of the cell membrane layer of fat. Phospholipids are commonly encountered are:
 Lecithin containing amino alcohol type kolina
 Kepalin containing amino alcohol type serine or ethanolamine.
The nature of the character depends phospholipid fatty acids and amino alcohols were tied.
 Sfingolipid

Sfingolipid is a complex family of compounds that share the same structural features, the basic framework sfingoid bases are synthesized de novo from amino acids serine and long-chain fatty acyl CoA, which is then converted into ceramides, fosfosfingolipid, glisosfingolipid, and compounds other.
Sfingolipid name is taken from Greek mythology, Spinx, half woman and half lion destroy anyone who is not able to answer the riddle. Sfingolipid discovered by Johann Thudichum in 1874 as a puzzle that is very complex from brain tissue.
Sfingolipid second type of fat is found in the cell membranes, especially in nerve cells and brain tissue. They do not mengandunggliserol, but can hold two alcohol groups at the center of the frame amines.
The main Fosfosfingolipid in mammals is sphingomyelin (ceramides fosfokolina), while the insects mainly contain ceramides fosfoetanolamina and fungi have fitoseramida fosfoinositol and mannose-containing head groups.
Basa main sfingoid mammals commonly referred to as sfingosina. Ceramides (Tongue N-acyl-sfingoid) is the main subclass sfingoid base derivatives with fatty acids attached to the amide. Fatty acid is usually mono-unsaturated or saturated with chain length of 16 carbon atoms to 26 carbon atoms.
Glikosfingolipid is a diverse group of molecules that are composed of one or more sugar residues linked to alkaline sfingoid via a glycosidic bond.
 Lipid sterol
Sterol lipids, such as cholesterol and its derivatives, is an important component of membrane lipids, along with gliserofosfolipid and sphingomyelin. Steroids, all derived from the four-ring core structure melting of the same, has a varied biological roles as hormones danmolekul signaling. Steroid 18-carbon (C18) include the estrogen family, while the C19 steroids comprise the androgens such as testosterone danandrosteron. C21 subclass includes progestagen, as well as glucocorticoids and mineral okortikoid. Sekosteroid, consists of a wide range of bentukvitamin D, characterized by cleavage of the B ring of the core structure. Other examples of fatty acids and bile sterols are conjugate-conjugate, which in mammals are oxidized derivatives of cholesterol and are synthesized in the liver. In plants, the equivalent is a phytosterol compounds, such as beta-sitosterol, stigmasterol, and brasikasterol; latter compounds are also used as the growth of algae. Predominant sterol in fungal cell membranes is ergosterol.
 Lipid prenol
Lipid prenol synthesized from 5-carbon precursors isopentenyl pyrophosphate pyrophosphate dandimetilalil mostly generated through the passage mevalonic acid (MVA). Simple isoprenoids (linear alcohols, diphosphates, etc.) are formed from the addition of C5 units are continuous, and are classified according to the number of these terpene units. Structures containing more than 40 carbon known as polyterpenes. Carotenoids are important simple isoprenoids that function as antioxidants and as precursors of vitamin A. Example of an important class of biological molecules is another quinone and hydroquinone containing isoprenoid tail attached to the core kuinonoid which is not derived from isoprenoid. Vitamin E and vitamin K, as well ubikuinon, is an example of this class. Prokaryotes synthesize poliprenol (called baktoprenol) the terminal isoprenoid unit attached to oxygen remains unsaturated, whereas in animal poliprenol (dolikol) the terminal isoprenoid been reduced.
 Sakarolipid
Structure sakarolipid Kdo2-Lipid A. Glucosamine residues blue, red KDO residues, acyl chains in black and phosphate groups in green.
Sakarolipid (English: saccharolipid, glucolipid) is a fatty acid molecule attached directly with glucose to form membrane structures in accordance with dwilapis. In sakarolipid, monosakari and replacing ties glycerol with fatty acids, as occurs in gliserolipid and gliserofosfolipid.
Sakarolipid the best known are the acylated glucosamine precursors of the lipid A component of lipopolysaccharide on gram-negative bacteria. Lipid-A molecule is a disaccharide of glucosamine general, derived seven-fatty acyl chains. Minimal lipopolysaccharide required for growth of E. coli is Kdo2-Lipid A, which is a disaccharide of glucosamine-acyl berheksa that diglikosilasikan acid residues with two 3-deoxy-D-mano-oktulosonat (KDO).