Presentation on theme: "Organic Chemistry Unit 3"— Presentation transcript:
1 Organic Chemistry Unit 3 Objectives:Identify the monomers that form each of the major macromolecules.Compare and contrast dehydration synthesis (or a condensationreaction) to hydrolysis.Investigate (research) and explain the role of nutrients in health.Differentiate between the major types of organic compounds.Describe Carbon’s unique qualities and bonding patterns.Describe the types, purpose and function of carbohydrates, lipids,proteins, and nucleic acids in the bodyExplain how organic substances are namedResearch and report on various amino acids, etc.Explain how heat, pH, etc. can affect the structure and function ofproteins.Evaluate the benefits/risks of various nutrients or their deficienciesCompare/contrast hydrocarbons with carbohydrates
3 A whole area of scientific study surrounds the study of carbon. Carbon is unique in that it has 4 valence electrons that allow it to bondsingly with 4 other elements or form DOUBLE or even TRIPLE bonds. Although many molecules are bent, like the approx degreebend of a water molecule, carbon compounds can form chains,branched chains, or even carbon rings.Carbon can be surrounded by 4 hydrogen atoms to form methane.Two carbons singly bonded together and surrounded by hydrogenatoms form ethane. Notice the “- ane” ending? This signifies that onlySINGLE bonding is occurring between carbon atoms. When ANYdouble bond occurs anywhere between carbons in a carbon compound,an “- ene” suffix is usually added. Triple bonded compounds receive a“- yne” suffix.Common prefixes by number of carbons in a compound:meth -eth -prop -but -
4 Carbohydrates, lipids, proteins, etc. often have specific carbon combinations referred to as “R”-groups. These “R”-groups are alsoknown as “functional groups” or reactive groups. The differences in thevarious “R”-groups is often what makes one carbon compound differentfrom the next. Note: “R” groups are not always carbon combinations.Some “hints” are given as to what is present in an organic compoundby its name.For example:If “NH2” is present, it’s an amine. If “OH” is bonded to C, it’s an alcohol.If there is a double bonded “O” and an “OH” bonded to a C, it’s acarboxylic acid. (Amino acids have an amine and a carboxylic acid.)Amides have a dbl. bonded O and NH2 bound to a C.If there is a benzene ring (a 6 carbon ring with every other carbon in adouble bond to the next), it’s a phenyl group.If a group 7 halogen (F, Cl, Br, I), replaces an “H”, it’s an alkyl halide.An “O” between 2 “C”s is an ether.A single “C” with a dbl. bonded “O” and an “H” is an aldehyde. It’s aketone if the C has a double bonded “O” and joins to 2 other “C”s.Esters have a C with a single bond to 1 “O” and a dbl. bond to another
5 “Organic” refers to something living or once living (“organisms”). Although, in everyday life, “organic” can mean “grown naturally”, withoutsynthetic (man-made) chemicals. “Inorganic” refers to a never livingsubstance, like a mineral or a synthetic substance.Because living things are made primarily of compounds containingcarbon, organic chemistry is also referred to as the chemistry of carbonThe 4 major organic compounds are:CarbohydratesLipidsProteinsNucleic AcidsEach of these has single units, or building blocks, called monomers.Monomers may link to form more complex polymers (many units).
6 Carbohydrates:Carbohydrates get their name from the fact that they are composedof Carbon, Hydrogen, and Oxygen. These usually exist in a 1:2:1 ratio,also written as CnH2nOn or Cx(H2O)y. On the other hand, things madeprimarily of just hydrogen and carbon are called hydrocarbons. Ex:petroleum oil, natural gas, and coal (All of these developed afterorganic materials were subjected to heat and pressure for long timeperiods so they lost most of their oxygen atoms.)The monomer of a carbohydrate is a monosaccharide. (“Saccharum”means “sweet” in Latin.) These units usually consist of 3 to 7 carbons.These are often referred to as “simple sugars’.There are 3 monosaccharide isomers with the formula C6H12O6.They are: glucose (blood sugar, etc.), fructose (fruit sugar), andgalactose.
7 Glucose: Fructose: Galactose: Simple carbohydrates, such as these, are usually referred to asSugars or saccharides. Notice that most sugars have an “-ose” endingto their names.Two monosaccharides can join to form disaccharides via a dehydrationreaction (water is removed, an “H” from 1 monosaccharide joins with an “OH” ofanother). If 2 to 10 monosaccharides join, they are often referred to asoligosaccharides. More than 10 monosaccharides join to formpolysaccharides.Hydrolysis (breaking of water) can add a water molecule to a disaccharide orlarger group to split off a monosaccharide.
8 Maltose (grain sugar) and sucrose (table sugar) are both disaccharides. Hydrolysis breaks maltose into 2 glucose monomers and sucroseinto glucose and fructose.Animals produce the disaccharide, lactose, in their milk. The enzymelactase allows us to digest milk. However, if the tips of intestinal villihave been irritated or damaged, the cells that make lactase may notfunction. This frequently happens with hidden food allergies, likegluten intolerance. Occasionally, if the hidden allergen is strictlyavoided, these cells heal and milk can be better tolerated in the diet.Polysaccharides are often used to store carbohydrates for later energyuse. Starch (a glucose polymer) is an energy storage form for plants.Glycogen, in our muscles and liver, is a storage form of carbohydratesused by animals. (Anything with a “glyco-” means the substancecontains sugars/carbohydrates.)
9 Cellulose is a polysaccharide that forms the cell walls of plants but is not used for energy. It is part of wood, paper, cotton, etc. Cows andtermites can digest cellulose due to bacteria specific to their intestines,we cannot. Cellulose acts as roughage, or fiber, in our diets.In general, carbohydrates are the most abundant organiccomponents of plants. And plants, at least indirectly, are the mainsource of carbohydrates in our diets.Carbohydrates can form complexes with proteins, such asglucosamine, which is needed for joint health and is a component ofheparin, which prevents blood from clotting.Carbohydrates can form complexes with lipids. Glycolipids, alongwith glycoproteins, are associated with the cell membrane and its abilityto interact with other cells and invading viruses or bacteria. Theseglycolipids and glycoproteins are part of the cell determinants that giveyou your “A”, “B”, “AB”, or “O” blood type.
10 Some antibiotics (anti - against, bio - life), such as streptomycin, neomycin, and gentamicin are amino (protein related) sugars thatusually work even against bacteria resistant to penicillin.It is also interesting that the commercial synthesis of vitamin C startswith a sugar, L- sorbose (L and R are used to indicate left and right“handed” or “rotary” molecules). Vitamin C appears very similar toglucose. In fact, restricting carbohydrates in cancer patients’ dietswhile administering high doses of vitamin C can trick cancer cells intoabsorbing vitamin C instead of glucose. Cancer feeds on glucose butcan not use vitamin C which then helps destroy these cells. (Note:Cancer cells have 24x more glucose receptors than normal cells.)Vitamin C also blocks an enzyme from turning glucose into sorbitol inthe body. Sorbitol is also in many diet foods. It accumulates in thenerves, eyes, and kidneys possibly causing the damage found there indiabetics. Many disorders can occur if the body does not regulatesugar properly. These include diabetes (high blood sugar) andhypoglycemia (low blood sugar), also referred to as hyperinsulinemia
11 Lipids:Lipids (Greek “lipos” means fat) are very similar to carbohydrates buttend to have fewer oxygen molecules in proportion to carbon and hydrogenmolecules. This is also why fats tend to release 9 Kilocalories per gram ofenergy versus 4 Kcal per gram from carbohydrates. (Fats are more energydense.) While simple sugars usually dissolve readily in water, complexcarbohydrates and most fats do not.Fatty acids are “sort of” the monomers for lipids. Fatty acids can have 100%single bonds between carbons to form saturated fats. If there are any doublebonds, the fat is unsaturated. A single double-bonded fat is sometimes calledmonounsaturated (“mono-” = one). Whereas fats with more than 1 double bondare called polyunsaturated (poly = many). Double bonds usually only occurafter the 9th C.Saturated fats tend to be solids at room temperature (Ex: butter).Polyunsaturated fats tend to be liquid at room temperature. (Ex: vegetable oils)Hydrogenated fats, or trans fats, are polyunsaturated fats that areheated to high temperatures and forced to link to hydrogens to saturatethem to a point that they are usually semisolid or solid at room temperature.
12 An example of a hydrogenated fat is margarine, made from corn oil. Unfortunately, forced hydrogenation changes cis - form double bondsto an unnatural trans – form (hence “trans” fats) in those double bondsthat did not react during the hydrogenation process. (Only partialhydrogenation is performed because total hydrogenation makes foodshard and brittle.) These are suspected culprits in cell membrane(bi-lipid layer) problems and heart disease (carbohydrates are alsosuspect).So why are partially hydrogenated oils used? Becausepolyunsaturated oils tend to oxidize easily which makes them go bad(they become rancid).Remember:“LEO the lion says GERrrrrrr.”(Loss of electrons is oxidation and Gain of electrons is reduction)“Oil Rig”(Oxidation is loss and reduction is gain of an electron)
13 Omega-3 fatty acids have a double bond at the third to last Carbon. They are found in cold water fish and certain plants. These arebelieved to be important for heart health, autoimmune diseases, skindisorders, attention deficit disorder, and rheumatoid arthritis.DHA (docosahexaenoic acid) is an omega-3 fatty acid EXTREMELYimportant to brain health. It is part of the gray matter of the brain andretinal tissue of the eye. It is found in breast milk but was only fairlyrecently added to baby formulas when it was found that breast-fedbabies tended to have higher IQs than bottle-fed babies.Omega-6 fatty acids are also important to life but are usually in toohigh of a ratio to omega-3’s in the American diet. Many commonvegetable oils contain omega-6’s. Corn oil is an excellent example. Itis pervasive in processed food.
15 Triglycerides, more recently referred to as triacylglycerols, consist of a 3 carbon alcohol (an alcohol is an “OH” group), known as glycerol,with 3 long chain fatty acids attached. Triglycerides are a naturalpart of our body’s chemistry, but like cholesterol, people worry abouttheir heart health when they get to too high of levels. Although theseare fats, their blood levels seem to rise more when our diets are highin carbohydrates rather than fats. Decreasing carbohydrates seems toreduce triglyceride levels.Sterols (the “-ol” suffix indicates an alcohol is present) have 4 linkedcarbon rings. These include some very important biologicalsubstances, such as: Vitamin D (essential to bone development andmaintenance), cortisol (our body’s natural pain killer, but harmful athigh levels for longer periods of time), bile acids, and cholesterol.Cholesterol isn’t such a bad guy. It is needed to producetestosterone, estrogen, etc. It acts as a band-aid when tiny tears occurin blood vessels. So why the bad reputation?
16 (low density lipoproteins) and VLDL (very low density lipoproteins). High cholesterol has been linked to arteriosclerosis (hardening of the arteries)and atherosclerosis (plaque build-up) and to heart attacks and strokes whenbuild-ups of cholesterol (plaque) break away and plug a blood vessel to theheart or head. Gallstones can also form due to cholesterol deposits in the liverand gall bladder. Our liver makes cholesterol but we also eat it in our diets.Cholesterol is often referred to as HDL (high density lipoproteins), LDL,(low density lipoproteins) and VLDL (very low density lipoproteins).HDL is considered “good” cholesterol because it carries lipids from thetissues to the liver where it is excreted from the body. LDL (badcholesterol) has large and small molecules. We now know only one ofthese tends to carry lipids from the liver to the tissues or blood vesselswhere it can be deposited. The other is more like HDL. High blood sugar bindsto LDL and prevents it from binding to liver sites that would normally shut downcholesterol production (biofeedback)2. VLDL is considered “bad”.Although high cholesterol levels can be associated with heartattacks, many studies now show that LOW cholesterol may be a moreserious health problem. And, C– reactive protein and homocysteine(take B6, B12, and folic acid) are better indicators of impending heartattack or stroke.2 Energy Times, July/Aug. 2006, p.34 “Trouble From Head to Toe”, by Karyn Maier
17 It makes sense that if CRP (C – reactive protein) is high, cholesterol (our plaque forming band-aid) will also be high. Cholesterol is part ofour body’s response to inflammation and/or illness. CRP indicatesinflammation is in the body. The cause of high cholesterol is NOT adeficiency of lipitor or other cholesterol drugs (which carry warningsthat they may cause liver problems – the very organ that needs to be ingood health in order to properly control cholesterol). So, we need tolook for the cause of inflammation in the body or poor function of theliver.Other Lipids:Waxes are fatty acids that form a relatively hard, water repellantcovering on feathers, leaves, skin, etc.Prostaglandins are a group of lipids that can affect: heart rate, bloodpressure and clotting, allergic responses, fertility, fever, inflammation.While some prostaglandins reduce inflammation, others cause it.Aspirin blocks the formation of pain inducing prostaglandins fromarachidonic acid (some foods are high in this). This is probably how italso reduces fever.
18 Phospholipids, or phosphatides, include lecithin (important for cholesterol control due to its choline content and for blood sugar controldue to its inositol content), phosphatidylserine (needed for brainhealth/memory), and cephalins. Phospholipids are an extremelyimportant part of cell membranes (the lipid bi-layers). (Note: saturatedfat is low in choline which allows an increase in fat in the liver.Increasing choline helps the liver.)Soaps, ironically, are fat based. But “like dissolves like”, so a non-polar substance is needed to dissolve fats, which are non-polar.Extremely low fat diets can be dangerous. Fat is required in the dietto absorb vitamins A (skin and eye health), D (bone and teeth health),E (great anti-oxidant), and K (important for normal blood clotting). Fatmakes up the myelin sheath around our nerves. Disorders such asmultiple sclerosis occur if myelin is damaged or destroyed. Too littlefat in the diet of very restricted caloric diets can also affect the femalehormonal cycles. And, don’t forget, our brains are mostly fat!
19 Certain fatty acids, like caprylic acid and lauric acid (coconut oil) have anti-fungal (Candida) properties. Linoleic and linolenic acids areneeded to prevent scaliness of the skin.You are what you eat. The types of fat in our diets affect how suppleour cell membranes are, how healthy our brain is, and even our fatstores (adipose) themselves. For example, the melting point of dog fat(pretty gross, isn’t it) can be raised from 20 degrees Celsius to 40 deg. C.by feeding them mutton tallow or it can be lowered from 20 degreesCelsius to 0 deg. C. by feeding them linseed oil. Hog producers don’tlike to feed the swine too much liquid fat (oil) because their fat becomestoo soft to make lard. But beware! “A diet high in carbohydrate has a‘hardening’ effect… 1 ” forming fats with a higher melting point. Thiscan have the same impact as large amounts of “bad” fats with theadditional side effect of higher insulin levels disturbing our health.Carbs. are readily converted to fat in the body. Think: triglycerol)People storing fat in their mid-section tend to have high insulin levelsdue to higher carb. intake.1 Practical Physiological Chemistry by Hawk and Bergeim, eleventh addition, p.783
20 Protein:The monomers of proteins are amino acids. Like carbohydrates andlipids, they are primarily composed of C. H. O, but also contain nitrogenand occasionally sulfur.Amino acids link via dehydration synthesis (removal of 2 H’s and anOxygen) a.k.a. a condensation reaction to form dipeptides (2 aminoacids) or polypeptides. Proteins consist of 1 or more polypeptides.The bonds between amino acids are called peptide bonds.There are 20 amino acids used in protein synthesis, each with thecharacteristic amine group (NH2) on one end and a carboxyl group(COOH, a carboxylic acid) on the other. Of these 20 amino acids, somecan be made by the body and are considered “nonessential” in the diet,but the rest are “essential” and must be gotten from our food.While most of the amino acids are neutral, some are charged. It isthe sequence of amino acids that makes each protein unique. And it isthe proteins we make that give us our characteristics.
21 Proteins fold into specific shapes called conformations. The protein must be in its correct shape in order to function properly in the body. Aprotein can be unfolded, or denatured by temperature changes (Ex:excess heat), pH changes, or certain chemical treatments (such asformaldehyde). A protein can also take on the wrong shape if anincorrect amino acid is substituted. In sickle cell anemia, a chargedamino acid is substituted for a neutral a.a. and this causes the proteinto fold incorrectly on itself. This “sickles” the cells which then get stuckin blood vessels/capillaries in the organs. Areas suffer from lack ofoxygen and that causes damage, pain, and a shorter life span.Proteins not only form most of the structures of the body, but alsoform hair, nails, antibodies for our immune system, etc. They also formenzymes of many types (enzyme names usually have an –ase ending),hormones, and catalysts (enzymes that speed up or lower the energyneeded for a reaction without becoming part of the reaction itself).Again, pH (acidity) and temp. can affect the function of enzymes.
22 Essential Amino Acids include: Isoleucine, leucine, lysine (this has a positively charged R group),methionine, phenylalanine, threonine, tryptophan, and valine(Children also require arginine and histidine)“Nonessential” Amino Acids include:Alanine, arginine (positive charge), asparagine, aspartic acid(negative charge), cysteine, glutamine, glutamic acid (negative charge),glycine, histidine (positive charge), proline, serine, tyrosineGlycine is the most fundamental in structure:H The “H” on the left is replaced by different “R” groups for other amino acids. On dietaryH – C – COO – proteins, “complete” means all amino acidsare present. Note: positive a.a.’s are bases.NH3+
23 Nucleic Acids:There are 2 types of nucleic acids:Deoxyribonucleic acid (DNA)Ribonucleic acid (RNA)These are polymers of nucleotide monomers.Nucleotides consist of:a 5 carbon sugar (ribose or deoxyribose)at least one phosphate group (PO4)a nitrogenous base (cytosine, guanine, adenine, thymine OR uracil)DNA forms a double helix with hydrogen bonds holding bases together(C to G and A to T) as the “rungs” of the twisted ladder. Deoxyriboseand phosphate make the “ladder” rails. Nucleotide triplets code foramino acids. A sequence coding for a polypeptide is a gene.RNA is single stranded, uses ribose as its sugar, and comes in severalshapes and forms. RNA can even act as an enzyme.