Chapter2a

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Spring 2010 chapter 2a PowerPoint for BIOL2401 (Human Anatomy & Physiology) at San Antonio College with Alba.

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Chapter2a

  1. 1. Chapter 2: Chemistry Comes Alive
  2. 2. Why Chemistry??? <ul><li>Chemistry is everywhere, especially within the human body </li></ul><ul><li>Chemistry drives biological processes </li></ul><ul><li>We are composed of chemicals (water, protein, fat, DNA, etc) and the substances we ingest are chemicals as well </li></ul>
  3. 3. Structural Organization: Chemical Level <ul><li>Atoms/ Elements </li></ul><ul><li>Molecules/ </li></ul><ul><li>Compounds </li></ul><ul><li>Macromolecules </li></ul>
  4. 4. Basic Chemistry: Matter <ul><li>Chemistry is the study of the composition of matter and how this composition changes through chemical reactions </li></ul><ul><li>Matter is anything that occupies space and has mass </li></ul><ul><li>Matter exists in solid, liquid, and gaseous states </li></ul><ul><li>Within the body, all states or matter are evident </li></ul>
  5. 5. Basic Chemistry: Energy <ul><li>Energy is the capacity to do work or to put matter into motion </li></ul><ul><li>Kinetic Energy = energy in action </li></ul><ul><li>Potential Energy = stored energy </li></ul><ul><li>Energy form conversions: 1 st law of thermodynamics… </li></ul><ul><li>“ Neither matter nor energy can be created or destroyed” </li></ul>
  6. 6. Forms of Energy <ul><li>Chemical : Stored in chemical bonds (ex: ATP) </li></ul><ul><li>Electrical : From the movement of charged particles (ex: nerve impulses) </li></ul><ul><li>Mechanical : Energy directly involved in moving matter (ex: muscular contraction) </li></ul><ul><li>Radiant/ Electromagnetic : Energy that travels in waves (ex: Light, UV, X-rays) </li></ul>
  7. 7. Composition of Matter <ul><li>All matter is composed of elements </li></ul><ul><li>Each element is composed of atoms </li></ul><ul><li>Each element is has unique physical & chemical properties </li></ul><ul><li>Most important for the body = CHNOPS </li></ul>
  8. 8. Atomic Structure No charge, large particle, in nucleus Neutron - charge, small particle, around nucleus Electron + charge, large particle, in nucleus Proton Characteristics Subatomic Particle
  9. 9. Atoms of Elements <ul><li>Atomic Number = p + </li></ul><ul><li>p + = e - </li></ul><ul><li>Mass Number = p + + n o </li></ul>
  10. 10. Chemical Bonding <ul><li>e - are arranged in shells & orbitals </li></ul><ul><li>Valence shell electrons affect the reactivity of atoms </li></ul><ul><li>Octet rule </li></ul>
  11. 11. Molecules & Compounds <ul><li>Molecules = two or more chemically bound atoms </li></ul><ul><li>Two or more atoms of the same element (ex: H 2 , O 2 ) = molecule of an element </li></ul><ul><li>Two or more atoms of different elements (ex: H 2 O, NaCl) = molecule of a compound </li></ul>
  12. 12. Ionic Bonds <ul><li>e - can transfer & result in ion (charged) formation </li></ul><ul><li>Anions: Negatively charged ion, e- acceptor (Cl - ) </li></ul><ul><li>Cations: Positively charged ion, e- donor (Na + ) </li></ul><ul><li>Since opposites attract, the atoms stay close together </li></ul>
  13. 13. Covalent Bonds <ul><li>e - are shared in order to fill valence shells part-time </li></ul><ul><li>Covalent bonds involve a shared orbital </li></ul>
  14. 14. Polarity <ul><li>Nonpolar Covalent Molecules: </li></ul><ul><ul><li>Have equal e - pair sharing </li></ul></ul><ul><ul><li>Charge is balanced among atoms </li></ul></ul><ul><li>Polar Covalent Molecules: </li></ul><ul><ul><li>Unequal sharing of e - </li></ul></ul><ul><ul><li>Slight (–) charge on one end, slight (+) charge on another </li></ul></ul>
  15. 15. Hydrogen Bonds <ul><li>Occur when covalently bonded H atoms are weakly attracted by other atoms </li></ul><ul><li>Not a true bond but is a weak attraction </li></ul><ul><li>Important for DNA structure </li></ul>
  16. 16. Chemical Reactions <ul><li>Chemical equations symbolize chemical reactions </li></ul><ul><li>Components: Products & Reactants </li></ul><ul><li>Synthesis: A + B  A B </li></ul><ul><li>Decomposition: A B  A + B </li></ul><ul><li>Exchange: A B + C  A C + B </li></ul><ul><li>A B + C D  A D + C B </li></ul><ul><li>Some reactions are reversible </li></ul>A + B AB
  17. 17. Examples
  18. 18. Factors Affecting Reaction Rates <ul><li>Temperature: </li></ul><ul><li>Increased = Faster </li></ul><ul><li>Decreased = Slower </li></ul><ul><li>Reactant Concentration: </li></ul><ul><li>High = Faster </li></ul><ul><li>Low = Slow </li></ul><ul><li>Particle Size: </li></ul><ul><ul><ul><li>Small = Fast </li></ul></ul></ul><ul><ul><ul><li>Large = Slow </li></ul></ul></ul><ul><li>Catalysts: </li></ul><ul><li>Present = Fast </li></ul><ul><li>Absent = Slow </li></ul>
  19. 19. Biochemistry <ul><li>Biochemistry: The study of the chemical composition and reactions of living matter </li></ul><ul><li>Inorganic Compounds: All compounds that do not contain carbon (water, oxygen, salts) </li></ul><ul><li>Organic Compounds: All compounds that contain carbon (carbohydrates, lipids, proteins, nucleic acids) </li></ul>
  20. 20. Inorganic Compounds: Water <ul><li>Most abundant cellular component </li></ul><ul><li>High heat capacity </li></ul><ul><li>High heat of vaporization </li></ul><ul><li>Universal solvent </li></ul><ul><li>Forms hydration layers </li></ul><ul><li>Transports biochemicals </li></ul><ul><li>Reactive </li></ul><ul><li>Cushions </li></ul>
  21. 21. Inorganic Compounds: Salts <ul><li>Ionic compounds that do not contain H + or OH - </li></ul><ul><li>In water, dissociate into ions/ electrolytes </li></ul><ul><li>Ions are essential for: </li></ul><ul><ul><li>Nerve impulse transmission (Na, K) </li></ul></ul><ul><ul><li>Muscle contraction (Na, K) </li></ul></ul><ul><ul><li>Hemoglobin in blood (Fe) </li></ul></ul>
  22. 22. Inorganic Compounds: Acids & Bases <ul><li>Acids: Donate (release) H + / protons </li></ul><ul><ul><li>When dissolved in water, acids release H + and an anion </li></ul></ul><ul><ul><li> HCL  H + + Cl - </li></ul></ul><ul><li>Bases: Accept H + , commonly contain OH - </li></ul><ul><ul><li>When dissolved in water, bases release OH- and a cation. The OH- ion then immediately accepts H+ to form water </li></ul></ul><ul><ul><li> NaOH  Na + + OH - </li></ul></ul><ul><ul><li> OH - + H +  H 2 O </li></ul></ul>
  23. 23. pH Scale <ul><li>Measures H + ion concentrations </li></ul><ul><li>Acidic : </li></ul><ul><ul><li>[H+] > [OH-], pH= 0-6 </li></ul></ul><ul><li>Neutral : </li></ul><ul><ul><li>[H+] = [OH-], pH= 7 </li></ul></ul><ul><li>Basic/ Alkaline: </li></ul><ul><ul><li>[H+] < [OH-], pH= 8-14 </li></ul></ul>
  24. 24. Inorganic Compounds: Buffers <ul><li>Buffers: Chemicals that resist abrupt pH changes </li></ul><ul><ul><li>Function by donating H + when needed and by accepting H + when in excess </li></ul></ul><ul><ul><li>Very, very important for biological systems!!! </li></ul></ul><ul><ul><li>H 2 CO 3 HCO 3 - + H + </li></ul></ul>weak acid H + Donor weak base H + Acceptor Proton Rising pH Drop in pH
  25. 25. Organic Compounds <ul><li>Molecules unique to biological systems </li></ul><ul><ul><li>Carbohydrates </li></ul></ul><ul><ul><li>Lipids (fats) </li></ul></ul><ul><ul><li>Proteins </li></ul></ul><ul><ul><li>Nucleic Acids (DNA & RNA) </li></ul></ul><ul><li>Monomer, Dimer, Polymer </li></ul>
  26. 26. Building & Breaking Organic Compounds
  27. 27. Polymerization <ul><li>Chain-like molecules composed of monomeric units </li></ul><ul><li>Continuous dehydration synthesis can grow polymer chains </li></ul>

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