Human Anatomy and Physiology Eleventh Edition (Chapter 02A) PDF

Human Anatomy and Physiology Eleventh Edition Chapter 02 Part A Chemistry Comes Alive Nursing video https://mediaplayer.pearso...

Human Anatomy and Physiology Eleventh Edition Chapter 02 Part A Chemistry Comes Alive Nursing video https://mediaplayer.pearsoncm g.com/assets/Yde4USMB5tBZP6AuZoscpCM U23Z89oKE PowerPoint® Lectures Slides prepared by Karen Dunbar Kareiva, Ivy Tech Community College Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Chemistry and Physiological Reactions Body is made up of many chemicals Chemistry underlies all physiological reactions: – Movement, digestion, pumping of heart, nervous system Chemistry can be broken down into: – Basic chemistry – Biochemistry Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Basic Chemistry Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 2.1 Matter and Energy Matter Matter is anything that has mass and occupies space Matter can be seen, smelled, and/or felt Matter is composed of elements with certain chemical properties. CNHOPS Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Matter States of matter – Matter can exist in three possible states:  Solid: definite shape and volume  Liquid: changeable shape; definite volume  Gas: changeable shape and volume Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved  2.2 Atoms and Elements All matter is composed of elements – Elements are substances that cannot be broken down into simpler substances by ordinary chemical methods Four elements make up 96% of body: – , Hydrogen, Carbon, Nitrogen and Oxygen Periodic table lists all known elements Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 2.2 Atoms and Elements (2 of 3) All elements are made up of atoms, which are: – Unique building blocks for each element – Smallest particles of an element with properties of that element – What give each element its particular physical & chemical properties Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 2.2 Atoms and Elements Atomic symbol – One- or two-letter chemical shorthand for each element  Example: “O” for oxygen, “C” for carbon  Some symbols come from Latin names: “Na” (natrium) is sodium; “K” (kalium) is potassium Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Table 2.1-1 Bulk Elements Composing the Human Body Table 2.1-1 Common Elements Composing the Human Body Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Table 2.1-2 Trace Elements Composing the Human Body Table 2.1-2 Common Elements Composing the Human Body Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Structure of Atoms Atoms are composed of three subatomic particles: Protons Carry a positive charge (+) Neutrons Have no electrical charge (0) Electrons Carry a negative charge () Nucleus composed of Protons and Neutrons Electrons move around the nucleus Atoms are electrically neutral when the number of protons and electrons are equal Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Identifying Elements Different elements contain different numbers of subatomic particles – Hydrogen has 1 proton, 0 neutrons, and 1 electron – Helium has 2 protons, 2 neutrons, and 2 electrons – Lithium has 3 protons, 4 neutrons, and 3 electrons Identifying facts about an element include its atomic number, mass number, isotopes, and atomic weight Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Identifying Elements Atomic number – Number of protons in nucleus – Written as subscript to left of atomic symbol  Example: 3Li  the number of protons is always equal to number of electrons Mass number – Total number of protons and neutrons in nucleus  Total mass of atom – Written as superscript to left of atomic symbol  Example: 7Li Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Identifying Elements Isotopes – Structural variations of same element – Atoms contain same number of protons but differ in the number of neutrons they contain  Atomic numbers are same, but mass numbers different Atomic weight – The number of protons plus the number of neutrons in an atom Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Isotopes of hydrogen Figure 2.3 Isotopes of hydrogen. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Identifying Identifying facts about an element include atomic number mass number Isotopes atomic weight Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Radioisotopes (1 of 2) Radioisotopes are isotopes that decompose to more stable forms – Atom loses various subatomic particles  Sometimes loss results in an isotope becoming a different element – As isotope decays, subatomic particles that are being given off release a little energy  This energy is referred to as radioactivity  Can be detected and measured with scanners Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Radioisotopes (2 of 2) Radioisotopes are a valuable tool for biological research and medicine – used for diagnosis of disease – Carbon dating All radioactivity can damage living tissue – Some types can be used to destroy localized cancers – Some types cause cancer  Radon from uranium decay causes lung cancer Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 2.3 Combining Matter Molecules and Compounds Most atoms chemically combine with other atoms to form molecules and compounds – Molecule: general term for 2 or more atoms bonded together – Compound: specific molecule that has 2 or more different kinds of atoms bonded together  Example: C6H12O6  Molecules with only one type of atom (H2 or O2) are just called molecules Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Mixtures Most matter exists as mixtures: two or more components that are physically intermixed Three basic types of mixtures – Solutions – Colloids – Suspensions Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved The Three Basic Types of Mixtures Figure 2.4 The three basic types of mixtures. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Mixtures Solutions – Are homogeneous mixtures, meaning particles are evenly distributed throughout – Solvent: substance present in greatest amount  Usually a liquid, such as water – Solute(s): substance dissolved in solvent  Present in smaller amounts  Example: blood sugar – glucose is solute, and blood (plasma) is solvent Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Difference Between Mixtures and Compounds Three main differences: – Unlike compounds, mixtures do not involve chemical bonding between components – Mixtures can be separated by physical means, such as straining or filtering; compounds can be separated only by breaking their chemical bonds – Mixtures can be heterogeneous or homogeneous; compounds are only homogeneous – Simplified:  Atom: simplest form of element or one (C, H, N, O, P, S, Na, Cl)  Compound: two or more atoms chemically bonded together (H2, O2)  Mixture: two or more elements chemically bonded together (H2O, NaCl, NH4) – Not all molecues are compounds, but mixtures may be referred to as molecules...ie water molecule Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 2.4 Chemical Bonds Chemical bonds are “energy relationships” between electrons of reacting atoms – Chemical bonds are not actual physical structures Electrons are the subatomic particles that are involved in all chemical reactions – They determine whether a chemical reaction will take place and if so, what type of chemical bond is formed – Atoms are neutrally charged(protons and electrons are same) – Ions are charged( protons does not equal electrons) – If it gives up an electron, then it becomes more positive (+) anion – If it gains an electron, then it becomes more negative (-) cation Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Role of Electrons in Chemical Bonding Electrons can occupy areas around nucleus called electron shells – Each shell contains electrons that have a certain amount of kinetic and potential energy, so shells are also referred to as energy levels – Depending on its size, an atom can have up to 7 electron shells – Shells can hold only a specific number of electrons; the shell closest to nucleus is filled first  Shell 1 can hold only 2 electrons  Shell 2 holds a maximum of 8 electrons  Shell 3 holds a maximum of 18 electrons Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Role of Electrons in Chemical Bonding (2 of 3) Outermost electron shell is called valence shell – Electrons in valence shell have the most potential energy because they are farthest from nucleus – These are electrons that are involved in chemical reactions Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Role of Electrons in Chemical Bonding (3 of 3) Octet rule (rule of eights) – Atoms desire 8 electrons in their valence shell  Exceptions: smaller atoms (examples: H and He) want only 2 electrons in shell 1 – Desire to have 8 electrons is driving force behind chemical reactions  Noble gases already have full 8 valence electrons (or 2 for He) so are not chemically reactive – Most atoms do not have full valence shells  Atoms will gain, lose, or share electrons (form bonds) with other atoms to achieve stability of 8 electrons in valence shell Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Chemically Inert and Reactive Elements (1 of 2) Figure 2.5a Chemically inert elements. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Chemically Inert and Reactive Elements (2 of 2) Figure 2.5b Chemically reactive elements Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Three major types of chemical bonds – Ionic bonds – Covalent bonds – Hydrogen bonds strongest to weakest bond is Ionic bond > Covalent bond > Hydrogen bond > Vander Waals interaction. NOTE: Ionic bonds are stronger than the covalent bond in a vacuum condition, but sometimes covalent bond is stronger than the ionic bond in an aqueous medium because of ionic compound dissociation. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Ionic bonds – Ions are atoms that have gained or lost electrons and become charged  Number of protons does not equal number of electrons Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds – Ionic bonds: involve the transfer of valence shell electrons from one atom to another, resulting in ions  One becomes an anion (negative charge) – Atom that gained one or more electrons  One becomes a cation (positive charge) – Atom that lost one or more electrons Electrons are negative: gain more negative(anion) lose negative to become more positive(cation) – Attraction of opposite charges results in an ionic bond Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Formation of an Ionic Bond Figure 2.6a, b Formation of an ionic bond. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved  Formation of an Ionic Bond Most ionic compounds are salts Figure 2.6c Formation of an ionic bond. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Covalent bonds – Covalent bonds are formed by sharing of two or more valence shell electrons between two atoms, completing the outer shell.  Sharing of 2 electrons results in a single bond  Sharing of 4 electrons is a double bond  Sharing of 6 electrons is a triple bond – Allows each atom to fill its valence shell at least part of the time – Two types of covalent bonds:  Polar and nonpolar covalent bonds Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Formation of Covalent Bonds Figure 2.7a Formation of covalent bonds. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Formation of Covalent Bonds Figure 2.7b Formation of covalent bonds. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Formation of Covalent Bonds Figure 2.7c Formation of covalent bonds. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Covalent bonds (cont.) – Nonpolar covalent bonds  Equal sharing of electrons between atoms  Results in electrically balanced, nonpolar molecules such as CO2 Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Carbon Dioxide and Water Molecules Have Different Shapes, as Illustrated by Molecular Models (1 of 2) Figure 2.8a Carbon dioxide and water molecules have different shapes, as illustrated by molecular models. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Polar covalent bonds – Unequal sharing of electrons between 2 atoms – Results in electrically polar molecules – Atoms have different electron-attracting abilities, leading to unequal sharing  Atoms with greater electron-attracting ability are electronegative, and those with less are electropositive Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Polar covalent bonds (cont.) – H2O is a polar molecule  Oxygen is more electronegative, so it exerts a greater pull on shared electrons, giving it a partial negative charge and giving H a partial positive charge – Having two different charges is referred to as dipole Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Ionic, Polar Covalent, and Nonpolar Covalent Bonds Compared Along a Continuum Figure 2.9 Ionic, polar covalent, and nonpolar covalent bonds compared along a continuum. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Bonds Hydrogen bonds – Attractive force between electropositive hydrogen of one molecule and an electronegative atom of another molecule  Not true bond, more of a weak magnetic attraction – Common between dipoles such as water  What makes water liquid – Also act as intramolecular bonds, holding a large molecule in a three-dimensional shape Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Animation: Hydrogen Bonds Click here to view ADA compliant Animation: Hydrogen Bonds https://mediaplayer.pearsoncmg.com/assets/hydrogen-bonds Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Hydrogen Bonding Between Polar Water Molecules Figure 2.10a Hydrogen bonding between polar water molecules. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Hydrogen Bonding Between Polar Water Molecules Figure 2.10b Hydrogen bonding between polar water molecules. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Adhesion and Cohesion of Water Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 2.5 Chemical Reactions Chemical Equations Chemical reactions occur when chemical bonds are formed, rearranged, or broken These reactions can be written in symbolic forms called chemical equations Chemical equations contain: – Reactants: substances entering into reaction together – Product(s): resulting chemical end products – Amounts of reactants and products are shown in balanced equations Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Chemical Equations Compounds are represented as molecular formulas – Example: H2O or C6H12O6 – Subscript indicates atoms joined by bonds – Prefix denotes number of unjoined atoms or molecules Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Chemical Equations Compounds are represented as molecular formulas – Example: H2O or C6H12O6 or H2 or CH4 – In chemical equations, subscripts indicate how many atoms are joined by bonds, whereas prefix means number of unjoined atoms (example: 4H) Reactants Product H+H H2 (Hydrogen gas) 4H + 1C CH4 (Methane) Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Reactions (2 of 7) Figure 2.11a Types of chemical reactions. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Reactions 2. Decomposition reactions involve breakdown of a molecule into smaller molecules or its constituent atoms (reverse of synthesis reactions)  Involve catabolic (bond-breaking) reactions AB A  B Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Reactions Figure 2.11b Types of chemical reactions. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Reactions 3. Exchange reactions, also called displacement reactions, involve both synthesis and decomposition  Bonds are both made and broken AB  C AC  B and AB  CD AD  CB Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Reactions (6 of 7) Figure 2.11c Types of chemical reactions. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Types of Chemical Reactions In living systems, these reactions are also referred to as reduction-oxidation or redox reactions – Atoms are reduced when they gain electrons and oxidized when they lose electrons – Example: C6 H12 O6  6O 2 6CO 2  6H 2O  ATP  In this example, glucose is oxidized, and oxygen molecule is reduced Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Energy Flow in Chemical Reactions All chemical reactions are either exergonic or endergonic – Exergonic reactions result in a net release of energy (give off energy)  Products have less potential energy than reactants  Catabolic and oxidative reactions – Endergonic reactions result in a net absorption of energy (use up energy)  Products have more potential energy than reactants  Anabolic reactions Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Reversibility of Chemical Reactions All chemical reactions are theoretically reversible A  B  AB Chemical equilibrium occurs if neither a forward nor a reverse reaction is dominant Many biological reactions are not very reversible – Energy requirements to go backward are too high, or products have been removed Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Rate of Chemical Reactions The speed of chemical reactions can be affected by: – Temperature: increased temperatures usually increase rate of reaction – Concentration of reactants: increased concentrations usually increase rate – Particle size: smaller particles usually increase rate Catalysts – Catalysts increase the rate of reaction without being chemically changed or becoming part of the product – Enzymes are biological catalysts Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Energy Energy is the capacity to do work or put matter into motion Energy does not have mass, nor does it take up space It is less tangible than matter The greater the work done, the more energy it uses up Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Energy https://mediaplayer.pearsoncmg.com/assets/energy-concepts Kinetic versus potential energy Energy exists in two possible forms: Kinetic – energy in action Potential – stored (inactive) energy Energy can be transformed from potential to kinetic energy Stored energy can be released, resulting in action Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Energy Forms of energy – Chemical energy  Stored in bonds of chemical substances – Electrical energy  Results from movement of charged particles – Mechanical energy  Directly involved in moving matter – Radiant or electromagnetic energy  Travels in waves (example: heat, visible light, ultraviolet light, and X rays) Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Energy (4 of 4) Energy form conversions – Energy may be converted from one form to another  Example: turning on a lamp converts electrical energy to light energy – Energy conversion is inefficient  Some energy is “lost” as heat, which can be partly unusable energy Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Copyright Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved