Copyright © 2015 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 2 Chemistry, Matter, and Life

Copyright © 2015 Wolters Kluwer All Rights Reserved Key Terms acidchemistryionsalt amino acidcolloidisotopesolute anioncompoundlipidsolution aqueousdenaturationmoleculesolvent atomelectrolytenucleotidesteroid baseelectronneutronsubstrate bufferelementpHsuspension carbohydrateenzymeproteinvalence catalystglucoseproton cationglycogenradioactive

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemistry Science that deals with matter’s composition and properties Used to understand normal and abnormal body function

Copyright © 2015 Wolters Kluwer All Rights Reserved 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 © 2015 Wolters Kluwer All Rights Reserved Appendix 1 Periodic Table of the Elements What is the symbol and number for carbon? Elements (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Table 2-1 Some Common Elements NameSymbolFunction OxygenOPart of water; needed to metabolize nutrients for energy CarbonCBasis of all organic compounds; component of carbon dioxide, the gaseous byproduct of metabolism HydrogenHPart of water, participates in energy metabolism; determines the acidity of body fluids NitrogenNPresent in all proteins, ATP (the energy-storing compound), and nucleic acids (DNA and RNA) CalciumCaBuilds bones and teeth; needed for muscle contraction, nerve impulse conduction, and blood clotting PhosphorusPActive ingredient in ATP; builds bones and teeth; component of cell membranes and nucleic acids PotassiumKActive in nerve impulse conduction; muscle contraction SulfurSPart of many proteins SodiumNaActive in water balance, nerve impulse conduction, and muscle contraction IronFePart of hemoglobin, the compound that carries oxygen in red blood cells The elements are listed in decreasing order by weight in the body. Elements (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) Living matter contains 26 of 92 natural elements. 96% of body weight— four elements 4% of body weight— nine elements 0.1% of body weight—13 elements The body’s chemical composition by weight.

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) Atoms Smallest subunits of elements Cannot be broken down or changed by ordinary chemical and physical means

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) Atomic Structure Nucleus –At atom’s center –Composed of Protons; positively charged Neutrons; not charged Electrons –Negatively charged –Orbit in energy levels around the nucleus –Determine atom’s chemical reactivity

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-2 The oxygen atom. How does the proton number of this atom compare with the electron number? Elements (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) Atomic Number Equal to the number of protons in an atom’s nucleus. Also represents the number of electrons orbiting the nucleus. No two elements share the same atomic number. 8 Oxygen O Oxygen’s nucleus contains eight protons. Its atomic number is 8.

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) Energy Levels Regions around an atom’s nucleus where electrons orbit. 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.

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) 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. HydrogenCarbon Total number of electrons16 Number of electrons in first energy level12 Number of electrons in second energy level04

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) Energy Levels (cont.) An atom will form chemical bonds with other atoms to fill its outermost energy level. An atom will donate, accept, or share electrons to fill its outermost energy level.

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-3 Examples of atoms. How many electrons does oxygen need to complete its outermost energy level? How does magnesium achieve a stable outermost energy level? Elements (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) ? Pop Quiz 2.1Which element makes up the greatest percentage of body weight? A)Nitrogen B)Oxygen C)Potassium D)Sodium

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) ? Pop Quiz Answer 2.1Which element makes up the greatest percentage of body weight? A)Nitrogen B)Oxygen C)Potassium D)Sodium

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) ? Pop Quiz 2.2The atomic number of iron is 26. How many protons does iron have? A)13 B)26 C)39 D)52

Copyright © 2015 Wolters Kluwer All Rights Reserved Elements (cont.) ? Pop Quiz Answer 2.2The atomic number of iron is 26. How many protons does iron have? A)13 B)26 C)39 D)52

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) An atom forms chemical bonds with other atoms to fill its outermost energy level with electrons. –Electrons may be transferred between atoms. –Electrons may be shared between atoms.

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Valence The number of bonds an atom needs to fill its outermost energy level. Example A carbon atom has six electrons. Its outermost energy level contains four electrons. It needs four more electrons to fill its outermost energy level. Carbon’s valence is 4. 6 Carbon C 12.01

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Ionic Bonds Form when one atom transfers electrons to another atom –The atom that donates an electron becomes a positively charged cation. –The atom that accepts an electron becomes a negatively charged anion. –The ionic bond is the attraction between oppositely charged ions. Na + Cl – Na + Cl –

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-4 Ionic bonding. How many electrons are in the outermost energy level of a sodium atom? Of a chlorine atom? Chemical Bonds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Electrolytes Compounds that separate into ions in solution Term also used to refer to the ions themselves Example Sodium chloride (NaCl) is an electrolyte. When NaCl is added to water, it separates into Na + and Cl − ions. Both Na + and Cl − ions are electrolytes.

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Ions in the Body Ions play important physiologic roles in body fluid. Homeostasis maintains proper ion concentration. Examples IonFunctions Ca 2+ Blood clotting, muscle contraction HCO 3 − pH regulation

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Ions in the Body (cont.) Ions conduct electric currents in body fluid. Measurement of a tissue’s electrical activity is used to diagnose disease. Examples ElectrocardiogramA record of the heart’s electrical activity ElectroencephalogramA record of the brain’s electrical activity

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Covalent Bonds Form when two atoms share electrons The most common chemical bond in the body Types: –Nonpolar covalent bond Electrons are shared equally. –Polar covalent bond Electrons are shared unequally.

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-5 A nonpolar covalent bond. How many electrons are needed to complete the energy level of each hydrogen atom? Chemical Bonds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-6 Formation of water. How many hydrogen atoms bond with an oxygen atom to form water? Chemical Bonds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) Molecules Chemicals composed of two or more atoms held together with covalent bonds –Examples: O 2, H 2 O Compounds Chemicals composed of two or more different atoms held together by ionic or covalent bonds –Examples: NaCl, H 2 O, CO 2

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) ? Pop Quiz 2.3What bond forms between two atoms that share their electrons equally? A)Hydrogen bond B)Ionic bond C)Nonpolar bond D)Polar bond

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) ? Pop Quiz Answer 2.3What bond forms between two atoms that share their electrons equally? A)Hydrogen bond B)Ionic bond C)Nonpolar bond D)Polar bond

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) ? Pop Quiz 2.4Which term best describes the sodium ion (Na + )? A)Anion B)Atom C)Electrolyte D)Element

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) ? Pop Quiz Answer 2.4Which term best describes the sodium ion (Na + )? A)Anion B)Atom C)Electrolyte D)Element

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) ? Pop Quiz 2.5Which chemical is NOT a compound? A)CO 2 B)H 2 O C)NaCl D)O 2

Copyright © 2015 Wolters Kluwer All Rights Reserved Chemical Bonds (cont.) ? Pop Quiz Answer 2.5Which chemical is NOT a compound? A)CO 2 B)H 2 O C)NaCl D)O 2

Copyright © 2015 Wolters Kluwer All Rights Reserved Mixtures (cont.) Table 2-2 Mixtures TypeDefinitionExample SolutionHomogeneous mixture formed when one substance (solute) dissolves in another (solvent) Table salt (NaCl) dissolved in water; table sugar (sucrose) dissolved in water SuspensionHeterogeneous 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 ColloidHeterogeneous mixture in which the suspended particles remain evenly distributed based on the small size and opposing charges of the particles Blood plasma; cytosol

Copyright © 2015 Wolters Kluwer 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 © 2015 Wolters Kluwer All Rights Reserved Mixtures (cont.) ? Pop Quiz 2.6Which term describes a substance that dissolves another substance? A)Mixture B)Solute C)Solution D)Solvent

Copyright © 2015 Wolters Kluwer All Rights Reserved Mixtures (cont.) ? Pop Quiz Answer 2.6Which term describes a substance that dissolves another substance? A)Mixture B)Solute C)Solution D)Solvent

Copyright © 2015 Wolters Kluwer All Rights Reserved Mixtures (cont.) ? Pop Quiz 2.7Which substance is termed the universal solvent? A)An acid B)A base C)Carbon D)Water

Copyright © 2015 Wolters Kluwer All Rights Reserved Mixtures (cont.) ? Pop Quiz Answer 2.7Which substance is termed the universal solvent? A)An acid B)A base C)Carbon D)Water

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) Acid A substance that releases hydrogen ions Base A substance that releases hydroxide ions and accepts hydrogen ions Salt A substance formed by a reaction between an acid and a base HCl  H + + Cl − NaOH  Na + + OH − HCl + NaOH  NaCl + H 2 O

Copyright © 2015 Wolters Kluwer All Rights Reserved 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 –Acidosis: Body fluid pH less than 7.35 –Alkalosis: Body fluid pH greater than 7.45

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-7 The pH scale. What happens to the amount of hydroxide ion (OH – ) present in a solution when the amount of hydrogen ion (H + ) increases? Acids, Bases, and Salts (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) Buffers Chemicals that prevent sharp changes in H + concentration Are important in maintaining a relatively constant pH in body fluids

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) ? Pop Quiz 2.8Which substance always accepts hydrogen ions? A)An acid B)A base C)A buffer D)A salt

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) ? Pop Quiz Answer 2.8Which substance always accepts hydrogen ions? A)An acid B)A base C)A buffer D)A salt

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) ? Pop Quiz 2.9Which substance always has a pH below 7? A)An acid B)A base C)A buffer D)A salt

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) ? Pop Quiz Answer 2.9Which substance always has a pH below 7? A)An acid B)A base C)A buffer D)A salt

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) ? Pop Quiz 2.10Which substance is most important in maintaining a relatively constant pH in body fluids? A)An acid B)A base C)A buffer D)A salt

Copyright © 2015 Wolters Kluwer All Rights Reserved Acids, Bases, and Salts (cont.) ? Pop Quiz Answer 2.10Which substance is most important in maintaining a relatively constant pH in body fluids? A)An acid B)A base C)A buffer D)A salt

Copyright © 2015 Wolters Kluwer All Rights Reserved Isotopes and Radioactivity (cont.) 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) Examples Isotope Proton Number Neutron Number Atomic Weight Carbon Carbon Carbon

Copyright © 2015 Wolters Kluwer All Rights Reserved Isotopes and Radioactivity (cont.) Radioactivity Emission of atomic particles from an isotope Use of Radioactive Isotopes Used in the treatment of cancer –Radiation penetrates and destroys tumor cells. Used in diagnosis –Radioactive elements can be administered and detected internally to identify abnormalities—these are called tracers. Example: Radioactive iodine used to diagnose thyroid problems.

Copyright © 2015 Wolters Kluwer All Rights Reserved Isotopes and Radioactivity (cont.) ? Pop Quiz 2.11A form of an element that differs in its atomic weight from other forms of that same element is a(n) ____________. A)Compound B)Ion C)Isotope D)Molecule

Copyright © 2015 Wolters Kluwer All Rights Reserved Isotopes and Radioactivity (cont.) ? Pop Quiz Answer 2.11A form of an element that differs in its atomic weight from other forms of that same element is a(n) ____________. A)Compound B)Ion C)Isotope D)Molecule

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) Chemistry of Living Matter Hydrogen, oxygen, carbon, and nitrogen make up 96% of body weight. Organic Compounds Chemical compounds found in living things Built on the element carbon Main types –Carbohydrates –Lipids –Proteins

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) Carbohydrates Monosaccharides –Basic units of carbohydrates Disaccharides –Two monosaccharides linked together Polysaccharides –Many monosaccharides linked together CarbohydrateExamples MonosaccharideGlucose DisaccharideSucrose and lactose PolysaccharideGlycogen and starch

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-8 Examples of carbohydrates. What are the building blocks (monomers) of disaccharides and polysaccharides? Organic Compounds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) Lipids (Fats) Triglycerides –Simple fat composed of glycerol and three fatty acids Phospholipids –Complex lipid containing phosphorus Steroids –Contain rings of carbon atoms (e.g., cholesterol) LipidFunctions TriglycerideInsulates body, protects organs, stores energy PhospholipidMain component of cell membranes SteroidRegulate body function (e.g., cortisol, sex hormones)

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-9 Lipids. How many carbon atoms are in glycerol? Organic Compounds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) Proteins Contain nitrogen (and sometimes sulfur or phosphorus). Found as structural materials and metabolically active compounds. Composed of chains of amino acids held together by peptide bonds. The overall three-dimensional shape of a protein is caused by folding.

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-10 Proteins. What part of an amino acid contains nitrogen? Organic Compounds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) Enzymes Are proteins that speed up (catalyze) chemical reactions Work on specific substrates Are not used up or changed during a chemical reaction Work via the “lock-and-key” mechanism Denature in harsh conditions (e.g., extremes of temperature or pH)

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-11 Diagram of enzyme action. How does the shape of the enzyme before the reaction compare with its shape after the reaction? Organic Compounds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) Nucleotides Composed of: –A nitrogenous base –A sugar (usually ribose or deoxyribose) –A phosphate group Building blocks of DNA and RNA One type is a component of ATP

Copyright © 2015 Wolters Kluwer All Rights Reserved Figure 2-12 Nucleotides. What does the prefix tri- in adenosine triphosphate mean? Organic Compounds (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz 2.12Which element is the basis of organic chemistry? A)Carbon B)Hydrogen C)Nitrogen D)Oxygen

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz Answer 2.12Which element is the basis of organic chemistry? A)Carbon B)Hydrogen C)Nitrogen D)Oxygen

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz 2.13Which organic compound catalyzes metabolic reactions? A)Carbohydrate B)Enzyme C)Lipid D)Nucleotide

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz Answer 2.13Which organic compound catalyzes metabolic reactions? A)Carbohydrate B)Enzyme C)Lipid D)Nucleotide

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz 2.14Which organic compound is used to store genetic information? A)Carbohydrate B)Enzyme C)Lipid D)Nucleotide

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz Answer 2.14Which organic compound is used to store genetic information? A)Carbohydrate B)Enzyme C)Lipid D)Nucleotide

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz 2.15A substance that has a name ending in -ase is most likely a(n)? A)Carbohydrate B)Enzyme C)Lipid D)Nucleotide

Copyright © 2015 Wolters Kluwer All Rights Reserved Organic Compounds (cont.) ? Pop Quiz Answer 2.15A substance that has a name ending in -ase is most likely a(n)? A)Carbohydrate B)Enzyme C)Lipid D)Nucleotide

Copyright © 2015 Wolters Kluwer All Rights Reserved Case Study Learning Objective 15.Use the case study to discuss the importance of regulating body fluid quantity and composition.

Copyright © 2015 Wolters Kluwer All Rights Reserved Case Study (cont.) Margaret’s Case: Chemistry’s Role in Health Science Some terms that illustrate the importance of body fluid quantity and composition: –Dehydration –Hematocrit –Hypernatremia –Hypotension –Tachycardia

Copyright © 2015 Wolters Kluwer All Rights Reserved Word Anatomy Learning Objective 16.Show how word parts are used to build words related to chemistry, matter, and life.

Copyright © 2015 Wolters Kluwer All Rights Reserved Word Anatomy (cont.)

Copyright © 2015 Wolters Kluwer All Rights Reserved Word Anatomy (cont.)