Organic Chemistry PDF

Chapter 5 Organic Chemistry Online text: http://chemwiki.ucdavis.edu/ http://www.ochem4free.info/node/1  Natural source of Drug Molecules Organic chemistry is more than simply the study of carbon or the study of chemicals  What Is Organic...

Chapter 5 Organic Chemistry Online text: http://chemwiki.ucdavis.edu/ http://www.ochem4free.info/node/1  Natural source of Drug Molecules Organic chemistry is more than simply the study of carbon or the study of chemicals  What Is Organic Chemistry? Organic chemistry is the chemistry of carbon compounds present in living organisms. The study of molecules containing the carbon-hydrogen (Hydrocarbon, C-H) bond and their reactions. What Does an Organic Chemist Do? An organic chemist is a chemist with a college degree in chemistry, typically a doctorate or master's degree in organic chemistry, though a bachelor's degree in chemistry may be sufficient for some entry level positions. Organic chemists usually conduct research and development, in a laboratory setting. Pharmaceutical or chemical companies usually require the services of organic chemists, among others to: – develop a better painkilling drug. – formulate a shampoo that would result in silkier hair. – make a stain resistant carpet.  Why Is Organic Chemistry Important? It is the study of life and all of the chemical reactions related to life. Several careers apply an understanding of organic chemistry, such as doctors, veterinarians, dentists, pharmacologists, chemical engineers, and chemists. Organic chemistry plays a part in the development of common household chemicals, foods, plastics, drugs, fuels... really most of the chemicals part of daily life.  Natural Sources of Organic Compounds Carbohydrates/ Enzymes/Nucleic acids/ Proteins / Fats / Vitamins / Antibiotics/ Hormones are derived from Living things e.g. animals, plants etc. A variety of organic products obtained from living things  Natural Sources of Organic Compounds Crude oil or coal Fractional distillation/ destructive distillation A variety of useful products derived from crude oil and coal  Development of Organic Chemistry as a Science In the past------/ Organic compounds were originally obtained from living organisms Inorganic compounds acquired from non- living sources  Development of Organic Chemistry as a Science In 1828, Friedrich Wohler (a German chemist) disproved the natural origin of organic compounds. He prepared urea, a carbon compound in urine, in the laboratory from inorganic compound. Inorganic Organic Compoun Compoun d d Classification of Organic Compounds  Why carbon is very important. Carbon is unique because it can bond with itself to form single , double or triple bonds. Carbon can form long chain or ring-like structures Carbon can bond with many elements on the periodic table such as H, N, O, S, etc Carbon is tetravalent, that is it has maximum of four bonds. Organic chemistry is therefore the study of carbon and its compounds.  Organic compounds are classified by the presence of characteristic functional groups.  Classification of Organic Compounds (1) Example General Functional Family formula group Formula IUPAC name Alkane RH (Nil) CH3CH3 Ethane RCH = CH2 RCH = CHR Alkene CH2 = CH2 Ethene R2C = CHR Carbon-carbon R2C = CR2 double bond RC  CH –CC– Alkyne Carbon-carbon HC  CH Ethyne RC  CR triple bond Aromatic ArH Benzene hydrocarbon Phenyl group  Nomenclature of Functional Groups IUPAC – International Union of Pure and Applied Chemistry R is obtained from alkanes by removing one H from the end carbon of the corresponding alkanes. A different functional group is then created when this removed atom is replaced with an atom (like halogen- Group 7A) or a group of atoms as in the following examples. Haloalkanes: R-F, R-Cl, R-BR, R-I…CH3F – Fluoromethane , CH3CH2Cl- Chloroethane etc Alcohols: R-OH –CH3OH-Methanol, CH3CH2OH-Ethanol  Functional Group Ethers: R- O – R -----CH3 – O- CH3 --- Methoxymethane Aldehydes: R – CH = O ---CH3-CH=O ----Ethanal Ketones: R2 - C = O ---- (CH3)2-C= O ---Propanone Carboxylic Acids: R-COOH ---CH3-COOH---- Ethanoic acid Esters: R-COOR’ ---CH3-COOCH3-----Methyl ethanoate Amines: R-NH2 ----CH3NH2------Methanamine  Classification of Organic Compounds(2) Example General Functional Family formula group Formula IUPAC name Haloalkane RX ¾X CH3Cl Chloromethane halo group Alcohol ROH  OH CH3OH Methanol hydroxyl group Ether O CH3 - O - CH3 Methoxymethane RO  R oxy group Aldehyde Methanal carbonyl group  Classification of Organic Compounds (3) Example Family General Functional formula group Formula IUPAC name Ketone Propanone carbonyl group Carboxylic acid Ethanoic acid carboxyl group RNH2 Amine R2NH CH3NH2 Methylamine R 3N amino group CN Nitrile RCN CH3CN Ethanenitrile nitrile group  Classification of Organic Compounds (4) Example General Functional Family formula group Formula IUPAC name Methyl Ester ethanoate ester group Ethanoyl Acyl halide chloride acyl halide group Amide Ethanamide amide group  Classification of Organic Compounds (5) Example General Functional Family formula group Formula IUPAC name Acid Ethanoic anhydride anhydride acid anhydride group R = CnH2n+1 Functional Groups A functional group is defined as an atom or a group of atoms. Effectively determines the chemical properties of an organic compound.  Functional Groups and have similar chemical properties  they contain the same functional group –OH  they are classified into the same homologous series — alcohols  Homologous Series A homologous series is a series of compounds that have the same functional group, and each member differs from the next member by a – CH2 – unit in their formulae. CH4 C2H6 C3H8 C4H10 CH2 CH2 CH2  Number IUPAC Molecular Condensed Structural of carbon name formula structural formula atom(s) formula 1 Methane CH4 CH4 2 Ethane C2H6 CH3CH3 3 Propane C3H8 CH3CH2CH3 4 Butane C4H10 CH3CH2CH2CH3 The first four members of straight-chain alkanes  Number IUPAC Molecular Condensed Structural of carbon name formula structural formula atom(s) formula 1 Methanol CH3OH CH3OH 2 Ethanol C2H5OH CH3CH2OH 3 Propan-1- C3H7OH CH3CH2CH2OH ol 4 Butan-1- C4H9OH CH3CH2CH2CH2OH ol The first four members of straight-chain alcohols  Homologous Series Members in the same series can be represented by a general formula. e.g. alkanes: CnH2n+2 alkenes: CnH2n alkynes: CnH2n-2 Members of a homologous series have similar chemical properties Physical Properties of Homologous Series The physical properties change gradually along the homologous series e.g. the longer the carbon chain in the molecule ( or the greater the molecular mass) the greater the attractive force between molecules the higher the melting point, boiling point and density  Some physical properties of the first 20 members of straight-chain alkanes State (at Number room Density of of Molecular temperature Melting Boiling solid / liquid at carbon formula point (°C) point (°C) and 20°C (g cm–3) atom(s) pressure) CH4 1 Gas –183 –161 – C 2H 6 2 Gas –172 –89 – 3 C 3H 8 Gas –188 –42 – 4 C4H10 Gas –135 0 – 5 C5H12 Liquid –130 36 0.626 6 C6H14 Liquid –95 69 0.657 7 C7H16 Liquid –91 98 0.684 8 C8H18 Liquid –57 126 0.703 9 C9H20 Liquid –54 151 0.718 10 Liquid –30 174 0.730 C10H22  Some physical properties of the first 20 members of straight-chain alkanes (CONTD.) State (at Number room Density of of Molecular Melting Boiling temperature solid / liquid at carbon formula point (°C) point (°C) and 20°C (g cm–3) atom(s) pressure) C11H24 11 Liquid –26 196 0.740 C12H26 12 Liquid –10 216 0.749 13 C13H28 Liquid –7 233 0.753 14 C14H30 Liquid –3 260 0.761 15 C15H32 Liquid 10 271 0.769 16 C16H34 Liquid 18 287 0.773 17 C17H36 Liquid 22 302 0.778 18 C18H38 Solid 28 316 0.777 19 C19H40 Solid 32 330 0.777 20 Solid 37 344 0.785 C20H42  Hydrocarbons Hydrocarbons are the simplest organic compounds. Hydrocarbons contain only carbon (C) and hydrogen (H). For classification purposes, all other organic compounds are considered derivatives of hydrocarbons. They contain O, N, S, and halogen in addition to carbon (C). Hydrocarbons can be divided into aliphatic and aromatic hydrocarbons.  Classification of Hydrocarbons Saturated Unsaturated Hydrocarbons Hydrocarbons  Aliphatic Hydrocarbons Aliphatic hydrocarbons are hydrocarbons having no benzene rings. Aliphatic hydrocarbons can be divided into four major divisions: Alkanes Cycloalkanes Alkenes Alkynes  R- Alkyl Groups Alkane Formula Alkyl group Formula methane CH4 methyl group -CH3 ethane CH3CH3 ethyl group -CH2CH3 propane CH3CH2CH3 n-propyl group -CH2CH2CH3 -CH2CH2CH2CH3 butane CH3CH2CH2CH3 n-butyl group R is obtained by removing one H from each alkane.  Alkanes Alkanes are hydrocarbons that contain only single bonds. Alkanes are said to be saturated hydrocarbons Each carbon is bonded to the maximum number of hydrogen atoms Alkane general formula  CnH2n + 2 The names of alkanes all end in “-ane.” Methane  butane are gases Pentane  C17H36 are liquids The First Eight Members of the Alkane Series All satisfy the general formula CnH2n +2 Copyright © Houghton Mifflin Company. All rights reserved. Visualization of an Alkane’s Structure Structural formula – a graphical representation of the way atoms are connected Condensed structural formula – save time/space and are convenient Ball-and-Stick models – 3D models that can be built by students Chemical Names, Structural Formulas, Condensed Structural Formulas, and Ball-and-Stick Models of Methane, Ethane, and Pentane  MATCHING PROBLEMS ALKANES Draw the structural formula for 2,3-dimethylhexane. Note that the end name is hexane. Draw a continuous chain of six carbon (C) atoms, with four bonds around each. Draw a line down on carbon 2 and 3, then place CH3 on each of them (CH3- is methyl), di-means two methyl groups joined to C-2 and C-3. C–C– C– C– C– C l l CH3 CH3  HOMOLOGOUS SERIES State whether each of the following pairs of compounds belongs to the same homologous series. Explain your answer Section 14.3  IUPAC Names The IUPAC names for each of the structures in the previous slide are: A = Propanoic acid ( R-COOH) B = Methyl ethanoate (R-COOR) C = 1-Butanol (OH is on c-1) D = 2-Butanol (OH is on C-2) They are not homologous series.  Cycloalkanes Members of the cycloalkane group possess rings of carbon atoms. They have the general formula CnH2n. Each carbon atom can have a maximum of four bonds. Therefore one hydrogen atom must be removed from the end carbon atoms of alkane to make a loop (ring)  C3 - C6 Cycloalkanes Note that in the condensed structural formulas, there is a carbon atom at each corner and enough hydrogen atoms are assumed to be attached to give a total of four single bonds.  Alkenes Members of the alkene group have a double bond between two carbon atoms. One hydrogen atom has been removed from two adjacent carbon atoms, thereby allowing the two adjacent carbon atoms to form a double bond. General formula is CnH2n Begins with ethene (ethylene) C2H4 Some Members of the Alkene Series Copyright © Houghton Mifflin Company. All rights reserved.  Naming Alkenes “-ane” suffix for the corresponding alkane is changed to “-ene” for alkenes. A number preceding the name indicates the “C” atom on which the double bond starts. The carbons are numbered such that the double bond has the lowest number. For example, 1-butene and 2-butene Alkenes are very Reactive and are termed “unsaturated hydrocarbons” Alkenes will characteristically react with more hydrogen atoms to form the corresponding saturated hydrocarbon (alkane).  Alkynes Members of the alkyne group have a triple bond between two carbon atoms. Two hydrogen atoms have been removed from each of two adjacent carbon atoms from alkanes, thereby allowing the two adjacent carbon atoms to form a triple bond. General formula is CnH2n-2 Begins with ethyne (acetylene) C2H2 Alkynes are Unsaturated Hydrocarbons Due to the triple carbon bond, each alkyne molecule can react with two molecules of hydrogen. Some Members of the Alkyne Series Copyright © Houghton Mifflin Company. All rights reserved.  Synthetic Polymers The first synthetic polymer was prepared by Leo Baekeland in 1907. Commercially this substance was used as an electrical insulator, called Bakelite. Chemists soon discovered new substances with very different properties by only slight substitutions to a molecule. Plastics are probably the best known of this group of synthetic polymers.  SYNTHETIC POLYMERS The most important commercial reactions of alkenes are polymerizations, reactions in which small molecules, referred to in general as monomers (from the Greek monos, meaning “one,” and meros, meaning “parts”), are assembled into giant molecules referred to as polymers (from the Greek poly, meaning “many,” and meros, meaning “parts”). A polymer is as different from its monomer as a long strand of spaghetti is from a tiny speck of flour. For example, polyethylene, the familiar waxy material used to make plastic bags, is made from the monomer ethylene—a gas.  Synthetic Polymers There are two major types of polymers: Addition polymers, e.g. polyethylene, polyvinyl chloride, polytetrafluoroethylene (Teflon), polystyrene, polypropylene, etc. Condensation polymers, e.g. Nylon Two different monomers combine together to eliminate a molecule of H2O to form these polymers e.g.  POLYMERIZATION There are two methods of forming these polymers: 1) addition polymerization and 2) condensation polymerization. In addition polymerization, the monomers add to one another in such a way that the polymer contains all the atoms of the starting monomers. For example: Ethylene molecules are joined together in long chains. The polymerization can be represented by the reaction of a few monomer units. CH2=CH2 + CH2=CH2 + CH2=CH2  -CH2-CH2-CH2-CH2- CH2-CH2-  ABBREVIATED STRUCTURE OF POLYMERS The bond lines extending at the ends in the formula of the product indicate that the structure extends for many units in each direction. Notice that all the atoms—two carbon atoms and four hydrogen atoms—of each monomer molecule are incorporated into the polymer structure. Because displays such as the one above are cumbersome, the polymerization is often abbreviated as follows:  Some Commo n Addition Polymer s Copyright © Houghton Mifflin Company. All rights reserved.  Condensation Polymers-Nylon Condensation polymers are formed from molecules of two or more reactive groups. Water is the other product, hence the name condensation polymers. Nylon was first introduced to the public in 1939 at the New York World’s Fair. Nylon is formed from the polymerization of adipic acid and hexamethylenediamine.  Aromatic Hydrocarbons Aromatic hydrocarbons contain one or more benzene ring. Benzene (C6H6) is the most important aromatic hydrocarbon. It is a clear, colorless liquid with a distinct odor, and is a carcinogen (cancer-causing agent.) Traditional Lewis Structure  Benzene Structural Formulas and Short-hand Symbols The Lewis structure and the Kekulé symbol both indicate that the carbons in the ring have alternating double and single bonds. Copyright © Houghton Mifflin Company. All rights reserved. Other Aromatic Hydrocarbons Toluene is used in modeling glue. Naphthalene is use in mothballs, and Phenanthrene are used in the synthesis of dyes, explosives, and drugs. Copyright © Houghton Mifflin Company. All rights reserved.  FUNCTIONAL GROUPS R represents alkyl groups such as methyl, ethyl, propyl, isopropyl etc Alcohols: R-OH Ethers: R-O-R’ Aldehydes: R – C H=O Ketones : R-C(R) = O Carboxylic acids: RCOOH or RCO2H Esters: RCOOR’ Amines: R-NH2, R2NH, R3N Amides: RCONH2  Alcohols Alcohols are organic compounds containing the hydroxyl group, —OH, attached to an alkyl group. General formula is R—OH Their IUPAC (International Union of Pure and Applied Chemistry) names end in “-ol.” The most simple alcohol is methanol Also called methyl alcohol or wood alcohol. (poisonous)  Alcohols Another common alcohol is ethanol. (CH3CH2OH) Also known as ethyl alcohol or grain alcohol Least toxic and most important of the alcohols Ethanol is used in alcoholic beverages, perfumes, dyes, and varnishes. Other Alcohol Examples Rubbing alcohol isopropyl alcohol (2- hydroxypropane) Ethylene glycol is an alcohol used widely as an antifreeze and coolant.  Other Alcohols Glycerol CH2- CH - CH2 Trihydroxy alcohol I I I OH OH OH Phenol--- Benzene ring with OH OH  Naming Alkoxy Groups Alkyl Group Name Alkoxy Group Name CH3– Methyl CH3O– Methoxy CH3CH2– Ethyl CH3CH2O– Ethoxy (CH3)2CH– Isopropyl (CH3)2CHO– Isopropoxy (CH3)3C– tert-Butyl (CH3)3CO– tert-Butoxy C6H 5– Phenyl C6H5O– Phenoxy  Naming Ethers Ethers are compounds having two alkyl or aryl groups bonded to an oxygen atom, as in the formula R1–O–R2. The smaller, shorter alkyl group becomes the alkoxy substituent. The larger, longer alkyl group side becomes the alkane base name. Each alkyl group on each side of the oxygen is numbered separately. The numbering priority is given to the carbon closest to the oxygen. The alkoxy side (shorter side) has an "-oxy" ending with its corresponding alkyl group. 1. Aldehydes take their name from their parent alkane chains. The -e is removed from the end and is replaced with -al. 2. The aldehyde functional group is given the #1 numbering location and this number is not included in the name. 3. For the common name of aldehydes start with the common parent chain name and add the suffix -aldehyde. Substituent positions are shown with Greek letters. 4. When the -CHO functional group is attached to a ring the suffix -carbaldehyde is added, and the carbon attached to that group is C1. 1. Ketones take their name from their parent alkane chains. The ending -e is removed and replaced with -one. 2. The common name for ketones are simply the substituent groups listed alphabetically + ketone. 3. Some common ketones are known by their generic names. Such as the fact that propanone is commonly referred to as acetone. http://chemwiki.ucdavis.edu/?title=Organic_Chemistry/Aldehydes_and_Ketones/ Nomenclature_of_Aldehydes_%26_Ketones  Naming of Ether Group Because there are two R groups, we have two ways of naming them. Example: CH3 – O – CH3------Methoxymethane or Dimethyl ether CH3CH2- O – CH3-----Methoxyethane or Ethyl methyl ether CH3CH2 O CH3 – O – CH2CH3---Ethoxyethane or Diethyl ether Methoxycyclohexane  Naming of Aldehydes and Ketones CH3CH2CH2CHO Butanal CH3CH2CH2CH2CHO Pentanal CH3COCH2CH3 ---Butanone or Ethyl methyl ketone CH3CH2 CO CH2CH3 ----Pentanone or Diethyl ketone  Carboxylic Acids Carboxylic acids contain the carboxyl group (–COOH) They have the general formula RCOOH.  Carboxylic Acids Formic acid is the simplest carboxylic acid. (This is the substance that causes the painful Vinegar is a 5% sting of insect bites). solution of acetic acid.  Naming of Carboxylic Acids and Esters CH3CH2CH2CH2COOH ---Pentanoic acid CH3CH2CH2CH2CH2CH2COOH-----Heptanoic acid CH3CH2 COO CH2CH3 ------Ethyl propanoate CH3CH2CH2CH2 COO CH3---Methyl pentanoate  Esters Ester – a compound that has the following general In formula RCOOR’ the general formula for an ester the R and R’ can be any alkyl group. Although R and R’ can be identical, they are usually different. Contrary to amines, most esters have pleasant odors. Many flowers and ripe fruits have fragrances and tastes due to one or more  Formation of an Ester Ester formation – the reaction of a carboxylic acid and an alcohol give an ester and water Heat is required and sulfuric acid is a catalyst. Note, in this reaction that the –OH from the carboxylic acid unites with the H from the alcohol to form H2O.  Ester-Methyl Salicylate Natural flavors and odors are generally complex mixtures of esters and other constituents Ester-Acetylsalicylic Acid (ASPIRIN) RCOOH, RCOOCH3 ester  Not Ester-Tylenol para-acetylaminophenol Amide R-CO-N, alcohol- R-OH  Amines Organic compounds that contain nitrogen and are basic (alkaline) are called amines. General formula for an amine is R—NH2. One or two additional alkyl groups could be attached to the N atom, in place of H atoms. Examples are methylamine, dimethylamine, and trimethylamine.  Amines – Strong Odors Most simple amines have strong odors. The odor given off by raw fish is due to an amine that it contains. Two particularly foul smelling amines are formed by decaying flesh. Cadaverine (1,5-diaminopentane) Putresine (1,4-diaminobutane)  Amines - Medicinal Many amines have medicinal applications. Amphetamines raise the glucose level in the blood resulting in less fatigue and hunger. But can be addictive and lead to insomnia, excessive weight loss, and paranoia. Benzedrine is one type of amphetamine.  Amides Amides are nitrogen-containing organic compounds with the general formula RCONHR’.  Amide Formation Amide formation is similar to ester formation. A carboxylic acid reacts with an amine to form water and an amide, as shown below.  Carbohydrates Compounds that contain multiple hydroxyl groups in their molecular structure. Names end in “-ose” Sugars, starches, and cellulose are the most important carbohydrates. Carbohydrates must be broken down into glucose for circulation in the blood.  Carbohydrates Carbohydrates are the primary source of energy for the body and include both simple sugars and larger complex carbohydrates. Your body can use carbohydrates right away or convert them into a storage form called glycogen. Excess carbohydrates can also be converted to fat. General formula - Cm(H2O)n, where m and n could go from 6 to hundreds Simple sugars- Glucose, Fructose, Galactose and Ribose  Monosaccharides One common simple sugar is glucose, C6(H2O)6, and it is the sugar our bodies and brains use for energy every day. Glucose is called a monosaccharide, which means "single sugar." It is found in grapes, figs, flowers and honey. Others are fructose, galactose, and ribose. Fructose is found in fruits, vegetables, and honey; galactose is found in milk; and ribose is best known as a part of ribonucleic acid, which is a part of genetic transcription and is found in the cells in our bodies.  Structures of Glucose, Fructose, and Sucrose Glucose (C6H12O6) and fructose (C6H12O6) are important sugars. Glucose + Fructose Sucrose + H2O (Cane sugar) commons.wikimedia.org  Disaccharides Disaccharides, a term that means "two sugars." These sugars include: Lactose (milk sugar) is made up of glucose and galactose molecules. People who are "lactose intolerant" can't digest this sugar properly. Sucrose (table sugar) is composed of glucose and fructose molecules. That's the white powdery or granular substance we typically refer to as "sugar" when we are cooking or baking. Maltose (malt sugar) is produced during the malting of cereals such as barley.  Complex Carbohydrates - Polysaccharides Complex carbohydrates are long chains of single sugar units. For example, starch is a polymer of many glucose units (monomer). These complex carbohydrates can be in the form of long chains, or the chains can form branches. Starch, the energy storage form of carbohydrates found in plants, especially in the seeds and roots. Starch is made up of many glucose units linked together. Starchy food examples include rice, wheat, corn, carrots, and potatoes. Starches are not water-soluble like the simple sugars, and require digestive enzymes called amylases to break them apart.  Complex Carbohydrates Glycogen, the energy storage form of glucose found in the muscles and livers of animals. You don't consume any carbohydrates when you eat meats; however, the amount of glycogen in animal tissue at the time of slaughter does affect the pH of the meat. Cellulose, the structural component of plants. Cellulose helps plants keep their shape; so in a way, cellulose acts as a plant skeleton. We are unable to digest cellulose; however, cellulose is one of the principal components of dietary fiber, along with lignin, chitin, pectin, beta-glucan, inulin and oligosaccharides.  Carbohydrates - Cellulose Cellulose is also a polymer of glucose and has the general formula (C6H10O5)n. Slightly different structure with different properties than starches Cell walls of plants are dominantly composed of cellulose. Humans do not have the appropriate enzymes (called cellulases) to break cellulose down. Termites and many herbivores contain  LIPIDS Fats are a subgroup of compounds known as lipids that are found in the body and have the general property of being hydrophobic (meaning they are insoluble in water). Fats are also known as triglycerides, molecules made from the combination of one molecule of glycerol with three fatty acids. A fat molecule which is an ester of fatty acid and glycerol is shown in the next slide: Formation of Fat— R - C17H35 + 3H2O  Fats (alcohol & -COOH deriv.) Fats are a type of ester formed by the combination of the trialcohol named glycerol and fatty acids. Glycerol is CH2(OH)CH(OH)CH2(OH) Stearic Acid (C17H35COOH) is found in beef fat, and is a typical fatty Generally acid. fats from animals are solid at room temperature. Fats from plants and fish are generally liquid at room temperature. Liquid fats are referred to as oils.  Hydrogenation Hydrogenation is the process of adding H to the C atoms that have a double bond. The hydrocarbon chains become saturated or nearly saturated and the liquid fat is changed to a solid. An example is the hydrogenation of cottonseed oil (Liquid) to Margarine (Solid).  Soaps Soap – the sodium salts of fatty acids Soap is formed by reacting a fat with sodium hydroxide (NaOH, lye.) The ester bonds break giving rise to glycerol and sodium salts of the fatty acids. Sodium stearate is a typical soap made up of hydrophobic and hydrophilic parts. What is soap? What is a Detergent?  How Do Soaps Work? How do soaps and detergents “dissolve” non-polar substances such as fats, oils, and greases? Molecules of soaps and detergents contain a non-polar (hydrophobic) hydrocarbon end, and a polar (hydrophilic) end that is usually ionic. The non-polar ends of the molecule surround the tiny oil droplets and are partially dissolved in them (like dissolves like). The polar ends of the molecules, which are extremely soluble in water, solubilize or emulsify the entire droplet  Soap versus Detergent Soaps do not work well in hard water because the divalent cations of dissolved minerals (Ca+2, Mg+2, and Fe+2) form precipitates with the carboxylate (fatty acid) anions of soaps. Consequently, a scum of calcium stearate (and other salts) is found as a ring in the bathtub or as a dingy film on clothes, hair, and skin. On the other hand, the alkyl sulfate and alkyl sulfonate anions of detergents do not form precipitates with these cations, so they are quite effective in hard water.  Amino Acid Amino acids are organic compounds that contain both an amino and carboxyl group. Glycine and alanine are the simplest amino acids. Proteins are extremely long polyamides, formed by the condensation of amino acids. Proteins can range from a few thousand formula units (insulin) to several million formula units. Amino Acid Structure Other Amino Acids Formation of Protein (Linking of Amino Acid Molecules) Glycine and alanine react to form water and another amino acid. This process can be repeated, eventually forming a protein. Ribose and 2-Deoxyribose Nitrogenous Bases  DRUGS-ORGANIC COMPOUNDS Broadly speaking, there are two major classifications of drugs, ‘synthetic drugs’ and ‘plant-based’ (also ‘botanical’ or ‘natural’) drugs. The Drug Expiry Date-Science Based Medicine If your medicine has expired, it may not provide the treatment you need due to deteriorated active pharmaceutical ingredients (API). Prescription drugs typically have an expiration date of one to five years (Mercola.com, Oct 22, 2012), dependable on dosage forms. Liquid and injectable drugs usually expire earlier. free2beinamerica2.wordpress.com  Do they mean anything to you? The date at which the manufacturer can still guarantee the full potency and safety of the drug. Expiry dates are a conservative measure to make sure you’re using medication of the highest potency possible. At the request of military, FDA conducted some studies (