chapt2student 2-1 Human Anatomy and Physiology I CHAPTER 2 Chemical Basis of Life

chapt2student Chapter 2 Chemical Basis of Life Why study chemistry in an Anatomy and Physiology class ? - ________________________________________ - cellular functions result from chemical changes - ______________________________________________ processes, and develop new drugs and methods for treating diseases 2-2

chapt2student Structure of Matter Matter – anything that takes up ___________________; composed of elements Elements – composed of chemically identical atoms bulk elements – ____________________________ amounts ________________ – required by the body in small amounts Atoms – ___________________________ 2-3

chapt2student Atomic Structure Atoms - composed of _________________ protons – carry a _____________ ________ – carry no electrical charge electrons – carry a __________ charge Nucleus __________________ composed of _______ and _________ ___________ move around the nucleus 2-4

chapt2student Atomic Number and Atomic Weight Atomic Number number of ________ in the ________ of one atom each element has a unique _______________ equals the number of electrons in the atom Atomic Weight the number of ________ plus the number of __________ in one atom __________ do not contribute to the weight of the atom 2-5

chapt2student Isotopes atoms with the same _____________ but with different atomic weights atoms with the same number of ________ and __________ but a different number of neutrons oxygen often forms isotopes (O 16, O 17, O 18 ) unstable isotopes are ____________; they emit subatomic particles 2-6

chapt2student Molecules and Compounds ___________ – particle formed when two or more atoms chemically combine Compound – particle formed when two or more ___________________ elements chemically combine Molecular formulas – depict the elements present and the number of each atom present in the molecule H 2 C 6 H 12 O 6 H 2 O 2-7

chapt2student Electrons found in regions of space called ________________ (energy shells) each shell can hold a _____________________________ for atoms with atomic numbers of ________, the following rules apply: the first shell can hold up to _________ the second shell can hold up to __________ the third shell can hold up to ______________ lower shells are filled first _____________________________________ 2-8

chapt2student Ions Ion an atom that has ______________________(s) an electrically charged atom _________________________ become stable Cation a ________ charged ion formed when an atom _______________ Anion a ________________ charged ion formed when an atom gains an electron(s) 2-9

chapt2student Ionic Bond an attraction between a ___________________ Ionic Bond formed when electrons are transferred from one atom to another atom 2-10

chapt2student Covalent Bond ________________________________ ____________ atoms form ____________ _________ atoms form ____ bonds Nitrogen atoms form three bonds ______________ form _____ bonds H ― H O = O N ≡ N O = C = O 2-11

chapt2student Structural Formula Structural formulas ________________________ arranged in various molecules 2-12

chapt2student Polar Molecules Polar Molecule molecule with a _____________ end and a slightly positive end results when electrons are ___________ equally in covalent bonds water is an important polar molecule 2-13

chapt2student Hydrogen Bonds Hydrogen Bond a ________________ between the positive end of one __________________ and the negative end of another polar molecule formed between _______________ important for ________ and nucleic acid structure 2-14

chapt2student Chemical Reactions Chemical reactions occur when ________________ form or break among atoms, ions, or molecules Reactants are _______________________ by the chemical reaction Products are _____________ formed at the end of the chemical reaction NaCl ’ Na + + Cl - ReactantProducts 2-15

chapt2student Types of Chemical Reactions Synthesis Reaction – ________________ are formed A + B ’ AB Decomposition Reaction – chemical bonds are __________ AB ’ A + B Exchange Reaction – chemical bonds are _________ and ______ AB + CD ’ AD + CB Reversible Reaction – the products can __________ to the reactants A + B AB 2-16

chapt2student Acids, Bases, and Salts Electrolytes – substances that release __________ Acids – __________ that release hydrogen ions in water HCl  H + + Cl - Bases – substances that ____________ that can combine with ________________ NaOH  Na + + OH - Salts – ____________ formed by the reaction between an _____________ NaCl  Na + + Cl - HCl + NaOH  H 2 O + NaCl 2-17

chapt2student Acid and Base Concentrations _________ - indicates the concentration of hydrogen ions in solution Neutral – ____ ; indicates equal concentrations of H + and OH - Acidic – pH less than 7; _________________ concentration of ___ Basic or alkaline – pH ______________; indicates a greater concentration of ___ 2-18

chapt2student Organic Versus Inorganic Organic molecules contain __________ usually larger than __________ molecules dissolve in ______ and ____________ ____________, proteins, lipids, and nucleic acids Inorganic molecules generally __________________ usually _________ than organic molecules usually ______________ or react with water to release ions water, _______, ___________, and inorganic salts 2-19

chapt2student Inorganic Substances Water most abundant compound in living material _____________ of the weight of an adult human major component of all body fluids ___________________________________ important role in transporting chemicals in the body can absorb and transport heat Oxygen (O 2 ) used by _____________ to release energy from nutrients necessary for survival 2-20

chapt2student Inorganic Substances Carbon dioxide (CO 2 ) __________________ released during metabolic reactions must be removed from the body Inorganic salts ___________________ sources of necessary ions (___, ___, ___, Ca 2+, etc.) play important roles in _________________ 2-21

chapt2student Organic Substances Carbohydrates provide _______________ to cells supply materials to build cell structures water-soluble contain ____________ ratio of H to O close to 2:1 (C 6 H 12 O 6 ) __________________ – glucose, fructose disaccharides – _______, _______ ________________ – glycogen, cellulose 2-22

chapt2student Organic Substances Carbohydrates 2-23

chapt2student Organic Substances Lipids soluble in organic solvents fats (_______________) used primarily for ______ contain C, H, and O but less O than carbohydrates (C 57 H 110 O 6 ) building blocks are __________ and __________ per molecule saturated and unsaturated 2-24

chapt2student Organic Substances Lipids phospholipids building blocks are 1 glycerol, 2 fatty acids, and 1 phosphate per molecule ___________________________ ______________________________ 2-25

chapt2student Organic Substances Lipids steroids connected _______________ component of _________________ used to ___________________ cholesterol 2-26

chapt2student Organic Substances Proteins structural material ________________ ___________ __________ ___________ building blocks are __________ amino acids held together with _________ bonds 2-27

chapt2student Organic Substances Proteins Four Levels of Structure 2-28

chapt2student Organic Substances Nucleic Acids constitute genes play role in _________________ building blocks are _____________ DNA (deoxyribonucleic acid) – double polynucleotide RNA (ribonucleic acid) – single polynucleotide 2-29

chapt2student Organic Substances Nucleic Acids 2-30

chapt2student Clinical Applications Radioactive Isotopes Reveal Physiology can be detected in the body using a scintillation counter injected into the body different types taken up by different organs can be used to destroy specific tissues commonly used _______ -131 for thyroid function thallium-201 for heart function gallium-67 and cobalt-60 for cancer others used to assess kidney functions, measure hormone levels and bone density changes 2-31