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Your 3 week old patient had a heel stick for blood work and has a Potassium level of 6.8meq (normal 3.5-5 meq). The infant is cooing at mom and drinking a bottle. The nurse should? 1. Ignore it 2. Have MD order more potassium 3. Give them a dose of magnesium sulfate STAT 4. Repeat the test Copyright ©2014 by Elsevier Inc. All rights reserved. Chapter 02 Chemistry of Life Copyright ©2014 by Elsevier Inc. All rights reserved. Lesson 2.1 Levels of Chemical Organization and Chemical Bonding Define the term and describe the structure of an atom. 2. Define the terms element, molecule, and compound. 3. Compare and contrast the major types of chemical bonding. 1. Copyright ©2014 by Elsevier Inc. All rights reserved. 3 Elements (cont.) Matter The substances from which the universe is made Elements All of the different types of matter Identified by names or chemical symbols Also identified by number Described and organized in the periodic table 11 Sodium Na 22.99 Copyright ©2014 by Elsevier Inc. All rights reserved. What is the symbol and number for carbon? Copyright ©2014 by Elsevier Inc. All rights reserved. Elements (cont.) Living matter contains 26 of 92 natural elements. The body’s chemical composition by weight. 96% of body weight— four elements 4% of body weight— nine elements 0.1% of body weight— 13 elements Copyright ©2014 by Elsevier Inc. All rights reserved. Levels of Chemical Organization Atom—smallest unit of matter Nucleus—central core of atom Proton—positively charged particle in nucleus Neutron—uncharged particle in nucleus Atomic number—number of protons in nucleus Atomic mass—number of protons and neutrons combined From Sugimoto Y et al: Chemical identification of individual surface atoms by atomic force microscopy, Nature 446:64-67, 2007. Copyright ©2014 by Elsevier Inc. All rights reserved. 7 Atoms Energy levels—orbital regions surrounding atomic nucleus that contain electrons Electron—negatively charged particle Each region has space for a specific number of electrons. The first energy level has room for two electrons. The second energy level has room for eight electrons. • • An atom is most stable when its energy levels are filled with electrons. Energy level increases the farther away it is from the nucleus Copyright ©2014 by Elsevier Inc. All rights reserved. 8 Models of the Atom Copyright ©2014 by Elsevier Inc. All rights reserved. 9 Elements (cont.) Hydrogen Carbon Total number of electrons 1 6 Number of electrons in first energy level 1 2 Number of electrons in second energy level 0 4 Energy Levels (cont.) Hydrogen has only one energy level with room for one more electron. Carbon’s first energy level is full. Carbon’s second energy level has room for four more electrons. Copyright ©2014 by Elsevier Inc. All rights reserved. Isotopes and Radioactivity (cont.) Examples Proton Number Neutron Number Atomic Weight Carbon-12 6 6 12 Carbon-13 6 7 13 Carbon-14 6 8 14 Isotope Isotopes Forms of an element that have the same atomic number but different atomic weight Different atomic weight because of a different number of neutrons May be stable or unstable (radioactive) Copyright ©2014 by Elsevier Inc. All rights reserved. Elements, Molecules, and Compounds Element—a pure substance; made up of only one kind of atom Molecule—a group of atoms bound together in a group Compound—substances whose molecules have more than one kind of atom Copyright ©2014 by Elsevier Inc. All rights reserved. 12 Name Oxygen Symbol O Function Part of water; needed to metabolize nutrients for energy Carbon C Basis of all organic compounds; component of carbon dioxide, the gaseous byproduct of metabolism Hydrogen H Part of water, participates in energy metabolism; determines the acidity of body fluids Nitrogen N Present in all proteins, ATP (the energystoring compound), and nucleic acids (DNA and RNA) Calcium Ca Builds bones and teeth; needed for muscle contraction, nerve impulse conduction, and blood clotting Phosphorus P Active ingredient in ATP; builds bones and teeth; component of cell membranes and nucleic acids Potassium K Active in nerve impulse conduction; muscle contraction Sulfur Sodium S Na Part of many proteins Active in water balance, nerve impulse conduction, and muscle contraction Iron Fe Part of hemoglobin, the compound that carries oxygen in red blood cells The elements are listed in decreasing order by weight ©2014 in the by body. Copyright Elsevier Inc. All rights reserved. Chemical Bonding Chemical bonds form to make atoms more stable. Atoms react with one another in ways that make their outermost energy level full. Atoms may share electrons or donate or borrow them to become stable. Copyright ©2014 by Elsevier Inc. All rights reserved. 14 Ionic Bonds Ions form when an atom gains or loses electrons in its outer energy level to become stable Positive ion—has lost electrons; indicated by superscript positive sign(s), as in Na+ or Ca++ Negative ion—has gained electrons; indicated by superscript negative sign(s), as in Cl– Copyright ©2014 by Elsevier Inc. All rights reserved. 15 Ionic Bonds Ionic bonds form when positive and negative (oppositely charged) ions attract each other Electrolyte—molecule that dissociates (breaks apart) in water to form individual ions; an ionic compound Copyright ©2014 by Elsevier Inc. All rights reserved. 16 Ionic Bonding Copyright ©2014 by Elsevier Inc. All rights reserved. 17 Covalent Bonds Covalent bonds form when atoms share their outer energy ions to complete the energy level and thus become stable. Covalent bonds do not ordinarily easily dissociate in water. Covalent bonding is used to form all of the major organic compounds found in the body. Copyright ©2014 by Elsevier Inc. All rights reserved. 18 Covalent Bonding Copyright ©2014 by Elsevier Inc. All rights reserved. 19 Hydrogen Bonds Hydrogen bonds do not create new molecules. Hydrogen bonds weakly bond to neighboring molecules. Hydrogen bonds are present in water, DNA, and proteins. Copyright ©2014 by Elsevier Inc. All rights reserved. 20 Hydrogen Bonds Copyright ©2014 by Elsevier Inc. All rights reserved. 21 Lesson 2.2 Inorganic and Organic Chemistry 4. Distinguish between organic and inorganic chemical compounds. 5. Discuss the chemical characteristics of water. 6. Explain the concept of pH. 7. Discuss the structure and function of the following types of organic molecules: carbohydrate, lipid, protein, and nucleic acid. Copyright ©2014 by Elsevier Inc. All rights reserved. 22 Inorganic Chemistry Organic molecules contain carbon-carbon covalent bonds and/or carbon-hydrogen covalent bonds; inorganic molecules do not. Organic molecules are generally larger and more complex than inorganic molecules. Copyright ©2014 by Elsevier Inc. All rights reserved. 23 Water Water is an inorganic compound essential to life. Water is a solvent (liquid into which solutes are dissolved), forming aqueous solutions in the body. Copyright ©2014 by Elsevier Inc. All rights reserved. 24 Mixtures Table 2-2 Mixtures Type Definition Example Solution Homogeneous mixture formed when one substance (solute) dissolves in another (solvent) Table salt (NaCl) dissolved in water; table sugar (sucrose) dissolved in water Suspension Heterogeneous mixture in which one substance is dispersed in another but will settle out unless constantly mixed Red blood cells in blood plasma; milk of magnesia Colloid Heterogeneous mixture in which the suspended particles remain evenly distributed based on the small size and opposing charges of the particles Blood plasma; cytosol Copyright ©2014 by Elsevier Inc. All rights reserved. Mixtures (cont.) The Importance of Water Most abundant compound in body Critical in all physiologic processes Deficiency (dehydration) threatens health Universal solvent Stable liquid at ordinary temperatures Participates in body’s chemical reactions Copyright ©2014 by Elsevier Inc. All rights reserved. Water Water is involved in chemical reactions: Dehydration synthesis Hydrolysis Chemical reactions always involve energy transfers, as when energy is used to build ATP molecules Chemical equations show how reactants interact to form products; arrows separate the reactants from the products Copyright ©2014 by Elsevier Inc. All rights reserved. 27 Acids, Bases, and Salts Acid A substance that releases hydrogen ions HCl H+ + Cl− Base A substance that releases hydroxide ions and accepts hydrogen ions NaOH Na+ + OH− Salt A substance formed by a reaction between an acid and a base HCl + NaOH NaCl + H2O Copyright ©2014 by Elsevier Inc. All rights reserved. Water-based Chemistry Copyright ©2014 by Elsevier Inc. All rights reserved. 29 Acids, Bases, and Salts Water molecules dissociate to form equal amounts of H+ (hydrogen ion) and OH– (hydroxide ion) Acid—substance that shifts the H+/OH– balance in favor of H+; opposite of base Base—substance that shifts the H+/OH– balance against H+; also known as an alkaline; opposite of acid Copyright ©2014 by Elsevier Inc. All rights reserved. 30 Acids, Bases, and Salts (cont.) The pH Scale Measures the relative concentrations of hydrogen and hydroxide ions in a solution. Scale from 0 (most acidic) to 14 (most basic). Each unit represents a 10-fold change. Normal body fluid pH range is between 7.35 and 7.45. Acidosis: Body fluid pH less than 7.35 Alkalosis: Body fluid pH greater than 7.45 Copyright ©2014 by Elsevier Inc. All rights reserved. pH pH—Mathematical expression of relative H+ concentration in an aqueous solution 7 is neutral (neither acid nor base) pH values above 7 are basic; pH values below 7 are acidic Copyright ©2014 by Elsevier Inc. All rights reserved. 32 pH Neutralization occurs when acids and bases mix and form salts. Buffers form chemical systems that absorb excess acids or bases and thus maintain a relatively stable pH. (proteins, Bicarbonate, or hemeoglobin) Copyright ©2014 by Elsevier Inc. All rights reserved. 33 Organic Chemistry Carbohydrates—sugars and complex carbohydrates Contain carbon (C), hydrogen (H), and oxygen (O) Monosaccharides—basic unit of carbohydrate molecules (for example, glucose) Disaccharide—double sugar made up of two monosaccharide units (for example, sucrose, lactose) Polysaccharide—complex carbohydrate made up of many monosaccharide units (for example, glycogen; stored by the body) Copyright ©2014 by Elsevier Inc. All rights reserved. 34 Carbohydrates Copyright ©2014 by Elsevier Inc. All rights reserved. 35 Lipids—Fats and Oils Triglycerides Formed by a glycerol unit and joined to three fatty acids Store energy for later use Copyright ©2014 by Elsevier Inc. All rights reserved. 36 Phospholipids Similar to triglyceride structure, but have phosphorus-containing units—each with a head and two tails The head attracts water and the double tail does not, thus forming stable double layers (bilayers) in water Form membranes of cells Copyright ©2014 by Elsevier Inc. All rights reserved. 37 Phospholipids Copyright ©2014 by Elsevier Inc. All rights reserved. 38 Cholesterol Molecules have a steroid structure made up of multiple rings Stabilizes the phospholipid tails in cellular membranes Also converted into steroid hormones by the body Copyright ©2014 by Elsevier Inc. All rights reserved. 39 Proteins Very large molecules made up of amino acids held together in long, folded chains by peptide bonds Structural proteins Form essential structures of the body Collagen is a fibrous protein that holds many tissues together Keratin forms tough, waterproof fibers in the outer layer of the skin Copyright ©2014 by Elsevier Inc. All rights reserved. 40 Protein Copyright ©2014 by Elsevier Inc. All rights reserved. 41 Functional Proteins Participate in chemical processes of the body Examples include hormones, cell membrane channels and receptors, and enzymes Enzymes—chemical catalysts Help chemical reactions occur Enzyme action sometimes called lock-and-key model Copyright ©2014 by Elsevier Inc. All rights reserved. 42 Enzyme Action Copyright ©2014 by Elsevier Inc. All rights reserved. 43 Nucleic Acids Made up of nucleotides A phosphate unit A sugar (ribose or deoxyribose) A nitrogen base (adenine, thymine or uracil, guanine, cytosine) Copyright ©2014 by Elsevier Inc. All rights reserved. 44 DNA (Deoxyribonucleic Acid) Used as the cell’s “master code” for assembling proteins Uses deoxyribose as the sugar and A, T (not U), C, and G as bases Forms a double helix shape Copyright ©2014 by Elsevier Inc. All rights reserved. 45 DNA Copyright ©2014 by Elsevier Inc. All rights reserved. 46 RNA (Ribonucleic Acid) Used as a temporary “working copy” of a gene (portion of the DNA code) Uses ribose as the sugar and A, U (not T), C, and G as bases Copyright ©2014 by Elsevier Inc. All rights reserved. 47 ATP (Adenosine Triphosphate) Copyright ©2014 by Elsevier Inc. All rights reserved. 48 Key Terms acid chemistry ion salt amino acid colloid isotope solute anion compound lipid solution aqueous denaturation molecule solvent atom electrolyte nucleotide steroid base electron neutron substrate buffer element pH suspension carbohydrate enzyme protein valence catalyst glucose proton cation glycogen radioactive Copyright ©2014 by Elsevier Inc. All rights reserved. Word Anatomy (cont.) Word Part Meaning Example Chemical Bonds co- together Covalent bonds form when atoms share electrons. Solutions and Suspensions aqu/e water In an aqueous solution, water is solvent. heter/o- different Heterogeneous solutions are different (not uniform) throughout. hom/o- same Homogeneous mixtures are the same throughout. hydr/o water Dehydration is a deficiency of water. phil to like Hydrophilic substances “like” water—they mix with or dissolve it. phobia to fear Hydrophobic substances “fear” water—they repel and do not dissolve it. Copyright ©2014 by Elsevier Inc. All rights reserved. Word Anatomy (cont.) Word Part Meaning Example Organic Compounds -ase suffix used in naming enzymes A lipase is an enzyme that acts on lipids. de- remove Denaturation of a protein removes its ability to function (changes its nature). di- twice, double A disaccharide consists of two simple sugars. glyc/o- glucose, sweet Glycogen is a storage form of glucose. It breaks down to release glucose. mon/o- one In a monosaccharide, “mono-” refers to one. poly- many A polysaccharide consists of many simple sugars. sacchar/o sugar A monosaccharide consists of one simple sugar. tri- three Triglycerides have one fatty acid attached to each of three carbon atoms. Copyright ©2014 by Elsevier Inc. All rights reserved.