<p>Ch 2 - Chemistry Comes Alive </p><p>BASIC CHEMISTRY</p><p> MATTER - Solid, liquid, gaseous states – all found in the human body</p><p>. ENERGY</p><p>. Less tangible, (not mass, fills no space)</p><p>. Def: the capacity to do work; or put matter into motion.</p><p>. The greater the work done, the more energy used.</p><p>Type of Energy:</p><p> Kinetic - Energy in action/motion</p><p>. Potential</p><p>. Stored energy; inactive energy.</p><p>. When potential energy is released it becomes kinetic energy</p><p>Forms of Energy</p><p>. Chemical energy - ATP (Adenosine triphospate) </p><p>. ATP is needed for cellular metabolism in the human body</p><p>. Electrical energy </p><p>. Results from charged particles (ions). </p><p>. Nerve impulses in the nervous system are electrical currents that transmit messages from one part of the body to another.</p><p>. Mechanical energy </p><p>. Directly involved in moving matter. Like riding a bike or the Stomach’s mechanical digestion</p><p>. Radiant energy – electromagnetic - Energy that travels through waves</p><p>MOLECULES</p><p>. Atoms combined with other atoms</p><p>. Compound molecules – 2 or more different6 kinds of atoms bind. Mixtures: solutions, colloids, suspension</p><p>. Solution – homogenous mixture of compounds</p><p>. Solvent – substance present in greatest amount.</p><p>. Solute - the substance present in smallest amount</p><p>Colloids – emulsions; a heterogeneous mixture</p><p>. Solute particles are larger than those in a solution</p><p>. Particles do not settle out. Ex: Cytosol</p><p>Suspensions – heterogeneous mixtures with large visible solutes</p><p>. Solute particles settle out. Ex: blood & plasma</p><p>Chemical Bonds</p><p>. Ionic Bonds – form by transferring one or more electrons from one atom to the other.</p><p>. Changes the balance of + (cation) or - (anion) charges to form an ion</p><p>. Covalent bonds – share the outer electron with the bonded atoms</p><p>. Hydrogen bonds – attractions rather than bonds, weakest bond.</p><p>. Forms when a H atom (already linked with another atom; N, O2) is attracted by another electron-hungry atom and bridges between Ex: water molecules</p><p>Organic compounds - Contain carbon, are covalently bonded, and are often large</p><p>Inorganic compounds - Do not contain carbon. Ex: water, salts, and many acids and bases</p><p>Properties of Water:</p><p>. High heat capacity – absorbs and releases large amounts of heat before changing temperature</p><p>. High heat of vaporization – changing from a liquid to a gas requires large amounts of heat</p><p>. Polar solvent properties – dissolves ionic substances, forms hydration layers around large charged molecules, and serves as the body’s major transport medium</p><p>. Reactivity – important part in hydrolysis and dehydration synthesis reactions</p><p>. Cushioning – resilient cushion around certain body organs Characteristics of water polarity</p><p>1. Liquid – remains liquid in our bodies</p><p>2. Universal solvent – helps facilitate chemical reactions in/out of our bodies</p><p>3. Cohesive properties – helps water-base solutions fill blood vessels</p><p>Salts: Inorganic compounds</p><p>. Contain cations other than H+ and anions other than OH– </p><p>. Are electrolytes; they conduct electrical currents</p><p>Water and Living Things: Characteristics of water polarity</p><p> Ability to change temperature slowly – prevents drastic changes</p><p> Vaporization – keeping body temperature from overheating</p><p> Ability to freeze – becomes less dense and in weight.</p><p>Acid – Base </p><p>. Water breaks up (dissociates) equal number of hydrogen (H) and hydroxide (OH) ions</p><p>. Acid solutions – release H</p><p>. Tomato juice, coffee, vinegar</p><p>. Sharp, sour taste associated with indigestion</p><p>. Basic solutions – release OH and gain H</p><p>. MOM, ammonia, household cleaners & detergents</p><p>. Bitter taste, become slippery when wet</p><p>. Acid-Base Concentration (pH)</p><p>. Necessary to maintain homeostasis</p><p>. Acidic solutions have higher H+ concentration and therefore a lower pH</p><p>. Alkaline solutions have lower H+ concentration and therefore a higher pH</p><p>. Neutral solutions have equal H+ and OH– concentrations</p><p>. The pH scale Buffers:</p><p>. Are systems that resist abrupt and large swings in the pH of body fluids</p><p>. Carbonic acid-bicarbonate system</p><p>. Carbonic acid dissociates, reversibly releasing bicarbonate ions and protons</p><p>. The chemical equilibrium between carbonic acid and bicarbonate resists pH changes in the blood</p><p>. They combine with Hydrogen (H) ions or hydroxide ions (OH) to resist pH changes</p><p>. Bicarbonate ions</p><p>. Stabilize pH within normal limits</p><p>. Take up excess H or OH molecules to resist pH changes</p><p>. Ex: Bufferin, shampoos, deodorants</p><p>ORGANIC MOLECULES</p><p>. Organic Compounds</p><p>. Molecules unique to living systems contain carbon and hence are organic compounds</p><p>. They include: Carbohydrates; Lipids; Proteins and Nucleic Acids</p><p>Organic molecule Structure: The molecules of life always:</p><p>. Are important to living organisms</p><p>. Always contain carbon and hydrogen</p><p>. Macromolecules – a large molecule structure containing many molecules joined together (polymers)</p><p>. Simple organic molecule - subunit of a polymer (monomers)</p><p>Carbohydrates: functions of carbohydrates</p><p>. Principal energy source for cells</p><p>. First function for short term energy storage</p><p>. Structural components in some cells </p><p>. Cell to cell recognition- surface antigens Carbohydrates - Contain carbon, hydrogen, and oxygen</p><p>. Their major function is to supply a source of cellular food</p><p>. Examples: Monosaccharides or simple sugars; Disaccharides or double sugars; Polysaccharides or polymers of simple sugars</p><p>Organic molecules</p><p>. Synthesis and degradation reactions in macromolecules</p><p>. `Dehydration synthesis</p><p>. Links monomers together to form a polymer</p><p>. 2 hydrogens and an oxygen removed in the reaction and unite to form water</p><p>. Water is also always a byproduct</p><p>. Hydrolysis</p><p>. Polymer is broken down to monomers</p><p>. Water is required to replace 2 hydrogens and the oxygen </p><p>Lipids</p><p>. Contain C, H, and O, but the proportion of oxygen in lipids is less than in carbohydrates</p><p>. Examples:</p><p>. Neutral fats or triglycerides</p><p>. Phospholipids</p><p>. Steroids</p><p>. Eicosanoids </p><p>. General characteristics of lipids are extremely diverse group of organic molecules: </p><p> fats, oils, steroids, waxes, phospholipids</p><p>. Common characteristic - nonpolar molecules which are insoluble in water</p><p>. Contain more calories of energy per gram so are ideal energy storage molecules</p><p>. Also function as structural components, insulation, cushioning of organs, and hormones</p><p>. Neutral Fats (Triglycerides) . Composed of three fatty acids bonded to a glycerol molecule</p><p>. Other Lipids include: Phospholipids – modified triglycerides with two fatty acid groups and a phosphorus group</p><p>. Lipids are broken down by Emulsification. Bile is an emulsifier</p><p>Fats are nonpolar; they do not dissolve in water and tend to form “globules” (oil and vinegar dressing)</p><p>Emulsifier breaks down the globules of fat into smaller droplets</p><p>Emulsifiers have a nonpolar end which attaches to the fat, and a polar end which interacts with water molecules so that the droplets can disperse </p><p>Other Lipids: </p><p>. Steroids – flat molecules with four interlocking hydrocarbon rings</p><p>. Eicosanoids – 20-carbon fatty acids found in cell membranes</p><p>. Representative Lipids Found in the Body</p><p>. Neutral fats – found in subcutaneous tissue and around organs</p><p>. Phospholipids – chief component of cell membranes</p><p>. Steroids – cholesterol, bile salts, vitamin D, sex hormones, and adrenal cortical hormones</p><p>Representative Lipids Found in the Body</p><p>. Fat-soluble vitamins – vitamins A, E, and K</p><p>. Eicosanoids – prostaglandins, leukotrienes, and thromboxanes</p><p>. Lipoproteins – transport fatty acids and cholesterol in the bloodstream </p><p>Amino Acids</p><p>. Building blocks of protein, containing an amino group and a carboxyl group</p><p>. Amino group (NH2)) and Carboxyl groups COOH</p><p>Protein - are Macromolecules composed of combinations of 20 types of amino acids bound together with peptide bonds</p><p>. Structural Levels of Proteins</p><p>. Primary – amino acid sequence</p><p>. Secondary – alpha helices or beta pleated sheets . Tertiary – superimposed folding of secondary structures</p><p>. Quaternary – polypeptide chains linked together in a specific manner</p><p>The Structural Levels of Proteins are: Fibrous and Globular Proteins</p><p>. Fibrous proteins</p><p>. Extended and strand-like proteins </p><p>. Examples: keratin, elastin, collagen, and certain contractile fibers</p><p>. Globular proteins </p><p>. Compact, spherical proteins with tertiary and quaternary structures</p><p>. Examples: antibodies, hormones, and enzymes</p><p>. Functions of Protein: </p><p>. Keratin – builds hair, nails and collagen</p><p>. Hormones – cellular metabolism </p><p>. Actin & myosin – movement of cells and muscular contractility</p><p>. Hemoglobin – transports oxygen in blood</p><p>. Antibodies – bind foreign subtances to prevent the destruction of cells</p><p>. Enzymes – speed up chemical reactions in the body </p><p>Protein Denuaturation</p><p>. The final shape of a protein molecule is often critical to its function</p><p>. Extreme exposure of heat and pH can change the shape of the protein molecule.</p><p>. Denaturation = irreversible change in shape</p><p>. Reversible unfolding of proteins due to drops in pH and/or increased temperature</p><p>. Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature change</p><p>. Once protein loses its normal shape it become dysfunctional</p><p>Characteristics of Enzymes</p><p>. Most are globular proteins that act as biological catalysts . Holoenzymes consist of an apoenzyme (protein) and a cofactor (usually an ion)</p><p>. Enzymes are chemically specific</p><p>. Frequently named for the type of reaction they catalyze</p><p>. Enzyme names usually end in -ase</p><p>Nucleic Acids</p><p>. Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus</p><p>. Their structural unit, the nucleotide, is composed of N-containing base, a pentose sugar, and a phosphate group</p><p>. Five nitrogen bases contribute to nucleotide structure – adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U)</p><p>. Two major classes – DNA and RNA</p><p>Deoxyribonucleic Acid (DNA)</p><p>. Double-stranded helical molecule found in the nucleus of the cell</p><p>. Replicates itself before the cell divides, ensuring genetic continuity</p><p>. Provides instructions for protein synthesis</p><p>. Structure of DNA</p><p>. Ribonucleic Acid (RNA)</p><p>. Single-stranded molecule found in both the nucleus and the cytoplasm of a cell</p><p>. Uses the nitrogenous base uracil instead of thymine</p><p>. Three varieties of RNA: messenger RNA, transfer RNA, and ribosomal RNA</p><p>Adenosine Triphosphate (ATP)</p><p>. Source of immediately usable energy for the cell</p><p>. Adenine - containing RNA nucleotide with three phosphate groups</p>