Lecture 3 August 17, 2007 Physiology Mester 1.) Review of how salt and sugar dissolve in water. Hot vs. cold See Lecture 2. Hydrolysis and condensation (also called dehydration) Hydrolysis From Wikipedia, the free encyclopedia Jump to: navigation, search Not to be confused with electrolysis Hydrolysis is a chemical reaction or process in which a chemical compound reacts with water. This is the type of reaction that is used to break down polymers. Water is added in this reaction. In organic chemistry, hydrolysis can be considered as the reverse or opposite of condensation, a reaction in which two molecular fragments are joined for each water molecule produced. As hydrolysis may be a reversible reaction, condensation and hydrolysis can take place at the same time, with the position of equilibrium determining the amount of each product. In inorganic chemistry, the word is often applied to solutions of salts and the reactions by which they are converted to new ionic species or to precipitates (oxides, hydroxides, or salts). The addition of a molecule of water to a chemical compound, without forming any other products is usually known as hydration, rather than hydrolysis. http://en.wikipedia.org/wiki/Hydrolysis Condensation reaction From Wikipedia, the free encyclopedia Jump to: navigation, search A condensation reaction is a chemical reaction in which two molecules or moieties combine to form one single molecule, together with the loss of a small molecule. When this small molecule is water, it is known as a dehydration reaction; other possible small molecules lost are hydrogen chloride, methanol, or acetic acid. A condensation reaction may be considered as the opposite of a hydrolysis reaction (the cleavage of a chemical entity into two parts by the action of water). Hydrolysis = H2O = H+ + OH- (cut water, stick the two pieces onto two different molecules) Condensation = p 40 – hydrolysis and dehydrolysis terms. Look them up. I looked them up online, instead. It was a lot easier to understand. Thermal properties of water - It takes a lot of heat to change the temperature of water. It takes one calorie ( c )of energy to change one ml of water 1 degree C. Water has a high heat capacity. The calories in food are kilocalories. ( C ) one kilo calorie is 1000 calories. It takes much more heat to burn a kilo calorie. (100 X 1000 = 100,000 calories!) Water works as a lubricant. It is a major component of mucus. The difference between a solution, a suspension and a colloid is that a solution has individual ions or molecules. They will dissolve, but stay. A colloid is when we have small particle. Multiple molecules. They are really small, Brownian motion. This will stay suspended by it’s random motion. Best example is; when we do dishes, we use hot water and soap. Then we put in the dirty dishes. The water turns cloudy because the sopa is interacting with the fat and other particles. They are help in the solution. They are not just water, they reflect the light. Look this up. The same thing happens in our lymphatic system coming from our digestive tract. When we digest fats, we form triglycerides and are paired with proteins and are moved out of the cells of the villi and into the interstitial place. They are moved into the lactiel into the lymphatic fluid. These are myceles of fat. They will separate, but our body takes small portions of the fat, coats with protein which has 4 edges to make hydrogen bonds with the water. The fluid becomes opaque instead of clear. (Same a when doing the dishes.) A suspension – the particles are larger. Materials will fall out of suspension. You need agitation to maintain suspension. When you cook rice or potatoes or pasta, you start off with clear water. The water looks cloudy after cooking. If you let it sit for a while, it will still lok cloudy. Those are the colloids. What will settle to the bottom are the suspension particles that have fallen out of suspension. Solutions, Suspensions, Colloids, and Dispersions From Anne Marie Helmenstine, Ph.D., Your Guide to Chemistry. FREE Newsletter. Sign Up Now! Mixture Chemistry Solutions A solution is a homogeneous mixture of two or more components. The dissolving agent is the solvent. The substance which is dissolved is the solute. The components of a solution are atoms, ions, or molecules, which makes them 10-9 m or smaller in diameter. Example: Sugar and Water Suspensions The particles in suspensions are larger than those found in solutions. Components of a suspension can be evenly distributed by a mechanical means, like by shaking the contents, but the components will settle out. Example: Oil and Water Colloids Particles intermediate in size between those found in solutions and suspensions can be mixed such that they remain evenly distributed without settling out. These particles range in size from 10-8 to 10-6 m in size and are termed colloidal particles or colloids. The mixture they form is called a colloidal dispersion. A colloidal dispersion consists of colloids in a dispersing medium. Example: Milk More Dispersions Liquids, solids, and gases all may be mixed to form colloidal dispersions. Aerosols: solid or liquid particles in a gas. Examples: Smoke is a solid in a gas. Fog is a liquid in a gas. Sols: solid particles in a liquid. Example: Milk of Magnesia is a sol with solid magnesium hydroxide in water. Emulsions: liquid particles in liquid. Example: Mayonnaise is oil in water. Gels: liquids in solid. Examples: gelatin is protein in water. Quicksand is sand in water. Telling Them Apart You can tell suspensions from colloids and solutions because the components of suspensions will eventually separate. Colloids can be distinguished from solutions using the Tyndall effect. A beam of light passing through a true solution, such as air, is not visible. Light passing through a colloidal dispersion, such as smoky or foggy air, will be reflected by the larger particles and the light beam will be visible. http://chemistry.about.com/od/lecturenotesl3/a/colloids.htm When we are looking at concentrations, we are talking about moles/L. (6.02 X 10 to the 23rd) The molar weight of solar chloride is 33. something grams. Measure that amount out, dissolve it in water. Bring it up to 1 L volume, then you will have a molar solution. Table 2.3: Percentage and molarity Definition: Percentage (mass per volume) – Number of grams of a substance per 100 ml of a solution. Example: To make a 10% NaCl solution, take 10 gm of NaCl and add enough water to make a total of 100 ml of solution. Definition: Molarity = moles (mol) per liter – A 1 molar (1 M) solution = 1 mole of a solute in 1 L of solution. Example: To make a 1 molar ( M) solution of NaCl, dissolve 1 mole of NaCl (58.44 gm) in enough water to make a total of 1 L of solution. What is molar mass? Molar mass is the weight of one mole (or 6.02 x 1023 molecules) of any chemical compounds. Molar masses of common chemical compounds that you might find in the chemistry laboratory can range between 18 grams/mole for compounds like water to hundreds of grams per mole for more complex chemical compounds. The lightest possible chemical that one can have under normal conditions is hydrogen gas, or H2. There is no limit to how heavy a chemical compound can be - it is not uncommon for macromolecules (large organic or bioorganic compounds such as DNA) to weigh thousands of grams per mole. http://misterguch.brinkster.net/molarmass.html Some molecules will spontaneously dissociate. A part of them comes off….if you put them into a solvent. Salts will do this in water. Other things can also dissociate. CO2 dissolved in water will make carbonic acid. This is what gives the acidity to soft drinks, beer, champagne, etc. When it spontaneously disassociates, it releases a proton. This is acidic. HCL will dissociate to H+ + Cl- Each molecule has its own propensity to dissociate. A certain amount of the molecule will dissociate. The more portion of the molecule that will dissociate, the stronger the acid. NaOH becomes Na+ + OH- (in water) This is a base. If you take and acid and a base and put them together, the hydrogen ion and the hydroxyl ion will form water and the other molecules will create a salt. This is a neutral solution. HCL + NaOH will make H2O + NaCl Table 2.3, Figure 2-12 When a sufficiently energetic electron collides with a molecule, it can transfer some of its energy to the molecule to produce an electronically excited state. Very often the excited state will have a potential surface that is unbound along some coordinate, as shown here schematically for hexafluoroethane, and will dissociate to neutral fragments (radicals or atoms). Even if the excited state surface has a minimum, electron-impact excitation may lead to dissociation if the transition is to a point on the surface above the energy needed to dissociate. Water can spontaneously dissociate. H2O becomes H+ +OH- Pure water is not pure water. It is water + a little bit of protons and a little bit of hydroxyls. Neutral water has a pH of 7. As there are more protons released, the protons get smaller. pH is a logarithmic scale. Our stomach releases protons and chloride ions into the lumen of our stomach, lowering the pH. After we eat a meal, out pH of the stomach is somewhere between 1 and 3. People who have bulimia-binge and purge- the pH of what they are vomiting up erodes the teeth, the esophagus, etc. Only the stomach can handle this acidity. Basic is corrosive. Acids and bases react with eachother to form salts. Figure 2.13 (pH scale) Table 2.4 (pH scale) Discussing blood buffer system. Buffer o Substance that helps resist drastic changes in pH. o Converts strong acids or bases into weak acids or bases by accepting or donating H+. Stopping Point CO2 + H2O H2CO3 BASE H+ + HCO-3 H+ + CO+/-3 Stopping Point ACID Discussion of hyperventilation. Hyperventilation From Wikipedia, the free encyclopedia In medicine, hyperventilation (or overbreathing) is the state of breathing faster and/or deeper than necessary, thereby reducing the carbon dioxide concentration of the blood below normal. This is in contrast to hyperpnea, where the increased breathing is required to meet demand, as during and following exercise or when the body lacks oxygen (hypoxia), for instance in high altitude or as a result of anaemia. Hyperpnea may also occur as a result of sepsis, and is usually a sign of the beginning of refractory sepsis. Hyperventilation can, but does not necessarily cause symptoms such as numbness or tingling in the hands, feet and lips, lightheadedness, dizziness, headache, chest pain, slurred speech and sometimes fainting, particularly when accompanied by the Valsalva maneuver. Sometimes hyperventilation is induced for these same effects. Hyperventilation can sometimes be self induced for moments of needed focus and adrenaline. The related symptom tachypnea (or "tachypnoea") (Greek: "rapid breathing") is characterized by rapid breathing and is not identical with hyperventilation - tachypnea may be necessary for a sufficient gas-exchange of the body, for example after exercise, in which case it is not hyperventilation. http://en.wikipedia.org/wiki/Hyperventilation http://innovexpo.itee.uq.edu.au/2001/projects/s804156/image1.jpg Pancreatic juice From Wikipedia, the free encyclopedia Pancreatic juice is a juice produced by the pancreas. It contains a variety of enzymes. They include trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase, and amylase. Pancreatic juice is alkaline in nature due to the high concentration of bicarbonate ions. This is useful in neutralizing the acidic gastric acid, allowing for effective enzymic action. Pancreatic juice secretion is regulated by the hormone secretin, which is released by the duodenum upon detection of proteins and fats. Pancreatic secretion consists of an aqueous bicarbonate component from the duct cells and enzymatic component from the acinar cells. http://en.wikipedia.org/wiki/Pancreatic_juice Vaginal fluid is slightly acidic, which discourages the growth of certain bacteria. Semen is slightly basic to protect itself from the acidity of vaginal fluids. Composition The lubrication fluid contains water, pyridine, squalene, urea, acetic acid, lactic acid, complex alcohols and glycols, ketones, and aldehydes. The fluid is typically clear and more resembling of male pre-ejaculate than male ejaculate. It can vary in consistency, texture, color, and odor, depending on sexual arousal, the time of the menstrual cycle, the presence of an infection, and diet. Vaginal fluid is slightly acidic and can become more acidic with certain sexually transmitted diseases. The normal pH of vaginal fluid is between 4.5 and 6, whereas male semen is typically between 7.1 and 8 (a neutral substance has a pH of 7). http://en.wikipedia.org/wiki/Vaginal_fluid Semen has a very high buffering capacity, much higher than that of most other fluids in the body. Semen maintains its pH near neutral in the acidic vaginal environment, providing the sperm with the opportunity to enter the neutral pH cervical mucus. http://www.andrologyjournal.org/cgi/content/full/26/4/459 Table 2.5 lists the most common functional groups of organic molecules and describes some of their properties. We need to know this table. The following is the closest thing I found to the table: II. Functional Groups A. Functional groups also contribute to the molecular diversity of life Small characteristic groups of atoms (functional groups) are frequently bonded to the carbon skeleton of organic molecules. These functional groups: • Have specific chemical and physical properties. • Are the regions of organic molecules which are commonly chemically reactive. • Behave consistently from one organic molecule to another. • Depending upon their number and arrangement, determine unique chemical properties of organic molecules in which they occur. As with hydrocarbons, diverse organic molecules found in living organisms have carbon skeletons. In fact, these molecules can be viewed as hydrocarbon derivatives with functional groups in place of H, bonded to carbon at various sites along the molecule. 1. The hydroxyl group Hydroxyl group = A functional group that consists of a hydrogen atom bonded to an oxygen atom, which in turn is bonded to carbon (—OH). • Is a polar group; the bond between the oxygen and hydrogen is a polar covalent bond. • Makes the molecule to which it is attached water soluble. Polar water molecules are attracted to the polar hydroxyl group which can form hydrogen bonds. • Organic compounds with hydroxyl groups are called alcohols. 2. The carbonyl group Carbonyl group = Functional group that consists of a carbon atom double-bonded to oxygen (—CO). • Is a polar group. The oxygen can be involved in hydrogen bonding, and molecules with his functional group are water soluble. • Is a functional group found in sugars. • If the carbonyl is at the end off the carbon skeleton, the compound is an aldehyde. • If the carbonyl is at the end of the carbon skeleton, the compound is a ketone. 3. The carboxyl group Carboxyl group = Functional group that consists of a carbon atom which is both double- bonded to an oxygen and single-bonded to the oxygen of a hydroxyl group (- COOH). • Is a polar group and water soluble. The covalent bond between oxygen and hydrogen is so polar, that the hydrogen reversibly dissociates as H~. This polarity results from the combined effect of the two electronegative oxygen atoms bonded to the same carbon. • Since it donates protons, this group has acidic properties. Compounds with this functional group are called carboxylic acids. 4. The amino group Amino group = Functional group that consists of a nitrogen atom bonded to two hydrogens and to the carbon skeleton (—NH2). • Is a polar group and soluble in water. • Acts as a weak base. The unshared pair of electrons on the nitrogen can accept a proton, giving the amino group a +1 charge. http://www.nmc.edu/~koverbaugh/bio115/chap4.htm Major Functional Groups. The shape of a molecule is everything. The functional groups control the shape of the molecules. Look up the role of R-S-H with the amino acid cysteine. Cysteine From Wikipedia, the free encyclopedia Cysteine Systematic (IUPAC) name (2R)-2-amino-3-sulfanyl-propanoic acid Identifiers CAS number 52-90-4 PubChem 5862 Chemical data Formula C3H7NO2S Mol. weight 121.16 SMILES N[C@@H](S)C(O)=O Complete data Cysteine is a naturally occurring, sulfur-containing amino acid that is a building block to most proteins. Cysteine is unique among the twenty common amino acids because it contains a thiol group. Thiol groups can undergo oxidation; a pair of cysteine residues is oxidised, producing cystine, a disulfide-containing derivative. This reaction is reversible. The disulphide bonds of cystine are crucial to defining the structures of many proteins. Related to its redox behavoir, cysteine is incorporated into many proteins that are redox- active, such as the antioxidant glutathione. Cysteine is named after cystine, which comes from the Greek word kustis meaning bladder − cystine was first isolated from kidney stones. http://en.wikipedia.org/wiki/Cysteine Sulfhydryl (R-S-H) Similar term(s): thiol Definition: -SH, a sulfur atom (S) bonded to a hydrogen (H) atom is a sulfhydryl group. A sulfhydryl compound contains one or more sulfhydryl groups. Examples include vitamin B-1 and the amino acid cysteine. http://www.greenfacts.org/glossary/pqrs/sulfhydryl.htm What gives hair it’s curliness or straightness is in the amount of cysteines and how they are linked together. Perms are a way of breaking existing bonds and refix the bonds in a different shape. Look this up! Curly hair has more cysteine. Curly hair differs from straight hair in the number of disulfide bond cross-links between methionine and cysteine amino acid units in individual keratin protein molecules. I am not certain how much variability there is between people in the methionine+cysteine content of their keratin. Certainly you can increase the number of disulfide bonds - and hence the amount of curl - chemically; this is called a perma nent wave. http://www.madsci.org/posts/archives/oct98/908952105.An.r.html Fructose is a keytone, but glucose is an aldehyde. Carboxylic acids : proteins + base vs. proteins + acid. (different response) Discussing buffer systems, again. How a buffer works. We make buffers out of the phosphate groups. You can make different mixtures of the phosphates where if you add acid or base, the pH does not change. That is what a buffer does. These are commonly made with phosphates. You can make a specific buffer for a specific acid or base! Chemists are nerds. Discussing blood buffer system again. We have chemical procedures going on in our blood to resist the change of pH. The kidneys, lungs, etc have these blood buffer systems. We have to maintain blood pH to maintain homeostasis. ―What are those systems for resisting change?‖ ―What happens if we fail to buffer the change or resist the change of the pH?‖ Amino groups – 5 valence e- It has the potential to make a 4th covalent bond to create a + charge. (Look this up) Figure 2-14 Be able to draw a glucose molecule with and without all the atoms written out. Study the drawings. Figure 2-15 See if you can find the visual on the internet. It’s pretty cool. Learn it…to a point. 1 glucose + 1 fructose = sucrose When these are dry, (glucose/fructose) they are linear in shape. When they come together, they make very tight hydrogen bonds. (example: making hard rock candy) The following link shows some pretty cool movies, including glucose + fructose = sucrose! http://science.nhmccd.edu/BioL/dehydrat/dehydrat.html Table 2.6 _ Major Carbohydrate Groups Types of Carbohydrates: Monosaccharides, Disaccharides, Polysaccharides What they are: Put simply, these are sugars and starches. Body fuel. When runners bulk up on carbohydrates before a marathon, they know what they're doing. Our bodies run on carbs much the way cars run on gas. Complex carbohydrates (those in pasta, the runner's favorite, potatoes, rice, dried peas and beans, grains) are nothing more than fancy configurations of hundreds, often thousands of glucose (simple sugar) molecules. Our bodies don't break these down into usable form very fast, especially if fiber is also present. Nutritionally speaking, all carbohydrates fall into one of three basic groups: Monosaccharides (simple sugars): These include fructose (fruit sugar) and glucose, often called blood sugar because it's what all carbohydrates are broken down into in the body. Only glucose circulates in the blood, providing energy to organs, glands, muscles, indeed to every cell. Finally, there is galactose, which rarely stands alone but does combine with other simple sugars, notably with glucose to form lactose (milk sugar). Disaccharides (double sugars): Nothing more than bonded pairs of simple sugars. There is sucrose (table sugar), glucose plus fructose; lactose (milk sugar), glucose plus galactose; and maltose (malt sugar), two linked glucose molecules. Polysaccharides (complex carbohydrates): Elaborate chains of glucose molecules, which from a nutritional standpoint are far and away the most important because they digest more slowly than simple or double sugars. Found in peas, beans, grains, potatoes and other starchy plants, they come freighted dietery fiber, vitmains and minerals. As far as calories are concerned, however, all carbohydrates are created equal. The monosaccharides, disaccharides and polysaccharides all weigh in at 4 calories per gram. Still, for all their pluses, too many carbs, like too much fat or protein, will put on the pounds. Nutritionists commonly recommend 55 to 60 percent of your daily calories should come from carbohydrates but recent research indicates that diabetes, heart disease and a myriad of other chronic degenerative diseases can be greatly reduced by consuming a greater ratio of proteins and fats and lesser amounts of carbohydrates. http://www.becomehealthynow.com/article/carbs/7 Starch From Wikipedia, the free encyclopedia Starch (CAS# 9005-25-8) is a complex carbohydrate which is soluble in water; it is used by plants as a way to store excess glucose and can be used as a thickening agent when dissolved and heated. The word is derived from Middle English sterchen, meaning to stiffen. The formula for Starch is C6H10O5.  In terms of human nutrition, starch is by far the most important of the polysaccharides. It constitutes more than half the carbohydrates even in affluent diets, and much more in poorer diets. It is supplied by traditional staple foods such as cereals, roots and tubers. Starch (in particular cornstarch) is used in cooking for thickening foods such as sauce. In industry, it is used in the manufacturing of adhesives, paper, textiles and as a mold in the manufacture of sweets such as wine gums and jelly beans. It is a white powder, and depending on the source, may be tasteless and odourless. Starch contains a mixture of two molecules: amylose and amylopectin. Usually these are found in a ratio of 30:70 or 20:80, with amylopectin found in larger amounts than amylose. Starch is often found in the fruit, seeds, rhizomes or tubers of plants. The major resources for starch production and consumption worldwide are rice, wheat, corn, and potatoes. Cooked foods containing starches include boiled rice, various forms of bread and noodles (including pasta). As an additive for food processing, arrowroot and tapioca are commonly used as well. Commonly used starches around the world are: arracacha, buckwheat, banana, barley, cassava, kudzu, oca, sago, sorghum, sweet potato, taro and yams. Edible beans, such as favas, lentils and peas, are also rich in starch. When a starch is pre-cooked, it can then be used to thicken cold foods. This is referred to as a pregelatinized starch. Otherwise starch requires heat to thicken, or "gelatinize." The actual temperature depends on the type of starch. A modified food starch undergoes one or more chemical modifications that allow it to function properly under high heat and/or shear frequently encountered during food processing. Food starches are typically used as thickeners and stabilizers in foods such as puddings, custards, soups, sauces, gravies, pie fillings, and salad dressings, but have many other uses. Resistant starch is starch that escapes digestion in the small intestine of healthy individuals. http://en.wikipedia.org/wiki/Starch Cellulose From Wikipedia, the free encyclopedia Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose is an organic compound with the formula (C6H10O5)n. It is a structural polysaccharide derived from beta-glucose. Cellulose is the primary structural component of green plants. The primary cell wall of green plants is made of cellulose; acetic acid bacteria are also known to synthesize cellulose, as well as many forms of algae, and the oomycetes. Cellulose was discovered and isolated in the mid-nineteenth century by the French chemist Anselme Payen with an estimated annual production of 1.5x109 Tonnes. Some animals, particularly,, ruminants and termites, can digest cellulose with the help of symbiotic micro-organisms - see methanogen. Cellulose is not digestible by humans and is often referred to as 'dietary fiber' or 'roughage', acting as a hydrophilic bulking agent for feces. http://en.wikipedia.org/wiki/Cellulose Glycogen From Wikipedia, the free encyclopedia Glycogen is a polysaccharide of glucose (Glc) which functions as the primary short term energy store in animal cells. It is the analogue of starch, a less branched glucose polymer in plants, and is commonly referred to as animal starch, having a similar structure to amylopectin. Glycogen is found in the form of granules in the cytosol in many cell types, and plays an important role in the glucose cycle. Glycogen forms an energy reserve that can be quickly mobilized to meet a sudden need for glucose, but one that is less compact than the energy reserves of triglycerides (fat). Only the glycogen stored in the liver can be made accessible to other organs, and these hepatocytes have the highest concentration of it—up to 8% of the fresh weight in well fed state, or 100–120 g in an adult. In the muscles, glycogen is found in a much lower concentration (1% of the muscle mass), but the total amount exceeds that in liver. Small amounts of glycogen are found in the kidneys, and even smaller amounts in certain glial cells in the brain and white blood cells. http://en.wikipedia.org/wiki/Glycogen http://images.google.com/imgres?imgurl=http://www.elmhurst.edu/~chm/vchembook/im ages/547glycogen.gif&imgrefurl=http://www.elmhurst.edu/~chm/vchembook/547glycog en.html&h=372&w=552&sz=20&hl=en&start=20&um=1&tbnid=1fxrnxZjS2TgZM:&tb nh=90&tbnw=133&prev=/images%3Fq%3D%252B%2522glycogen%2522%26svnum% 3D10%26um%3D1%26hl%3Den%26sa%3DN Why we call sugars and starches carbohydrates. Because we water carbon! C6H12O6 in its lowest term is CH2O! This is the basic formula for carbohydrates. Each gm of carbs has ~ 4.5 kilo calories per gm.