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Basic Chemistry

Basic Chemistry. Chapter 2. Why do I care?. What about your food? Medicines? Reactions in your body?. Matter and Energy. Matter = anything that takes up space and has mass Solids – bones, teeth – definite shape and volume Liquids – blood plasma – definite volume

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Basic Chemistry

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  1. Basic Chemistry Chapter 2

  2. Why do I care? • What about your food? • Medicines? • Reactions in your body?

  3. Matter and Energy • Matter = anything that takes up space and has mass • Solids – bones, teeth – definite shape and volume • Liquids – blood plasma – definite volume • Gas – Air we breathe – changes volume and shape • Changes to Matter • Physical changes – do not change basic nature of substance • Chemical changes – do alter basic nature of substance

  4. Matter and Energy • Energy = massless and doesn’t take up space • Ability to do work or put matter into motion • Kinetic vs. Potential Energy, all forms exhibit both

  5. Forms of Energy the Body Uses • Chemical – stored in bonds, when broken potential energy converted to kinetic – ATP • Electrical Energy – Movement of charged particles, electrical current generated when ions move across cell membranes – nerve impulses • Mechanical Energy – Directly involved in moving matter – muscle contraction, pulls on bones, limbs move • Radiant Energy – Electromagnetic spectrum, travels in waves – visible light stimulated retina, vision • Energy easily converted from one type to another

  6. Composition of MatterElements and Atoms • All matter composed of elements (can’t be broken down further) • Elements made of atoms, differ for each element • 96% of body made of C, O, H, N • See Table 2.1 for other trace elements

  7. Atomic Structure • Made of 3 subatomic particles • Proton (p+) – positive charge, found in nucleus • Neutron (n0) – neutral, found in nucleus • Electron (e-) – negative charge, found in nucleus, mass = 0 • Overall charge of atom = 0 • What does this mean? • p+ = e- • Atoms with a charge are called ions Figure 2.1

  8. Planetary and Orbital Models of Atom • Planetary Model – heavy elements in charged nucleus, electrons orbit around • Problem – we can never locate e-, jump around • Orbital Model – more recent, electron cloud, shading shows where e- likely to be found

  9. Identifying Elements • # of protons, neutrons, and electrons • Atomic Number - # of protons • Atomic Mass – sum of neutrons and protons • H is unique • Atomic Weight – Is it the same as Atomic Mass? Figure 2.2

  10. Atomic Weight • Isotopes – Same # of protons and electrons, but different # of neutrons • Same atomic #, different atomic masses • All will have same chemical properties • Atomic Weight is most abundant isotope • For Hydrogen AW=1.0079 Figure 2.3

  11. Periodic Table of Elements http://www.astro.virginia.edu/class/oconnell/astr121/cosmic-history-narrative.html

  12. Molecules and Compounds • Molecule = 2+ atoms combine chemically • Examples? • Molecule of an element = atoms of same elements H2, O2, N2 • Molecule of Compound = atoms of different elements H20, CO2, NaCl • Molecules of compounds have properties very different than that of it’s components • Na – silvery metal • Cl2 – poisonous gas • NaCl – makes my food taste better

  13. Chemical Bonds • Not physical structure, energy relationship between electrons of reacting atoms • Electron shells or energy levels – 1-7, held more strongly at 1. Figure 2.5

  14. Electron Shells • Shell 1 = 2 electrons • Shell 2 = 8 electrons • Shell 3 = 18 electrons • Etc. Shells filled 1 up • Valence Shell – Outermost shell, most important for chemical behavior of atom. Why? • Rule of 8s – outermost shell has 8 electrons, inert • Exception is Shell 1

  15. Types of Chemical BondsIonic • Complete transfer of electrons • Ions – charged atoms • Loss or gain of electrons completes valence shell, stability • Overall charge – like magnets • NaCl, mostly salts Figure 2.6

  16. Types of Chemical BondsCovalent • Electrons shared by atoms, valence shell filled part of time • Single, double, or triple bonds • Shared equally = nonpolar molecules • Share unequally = polar molecules, H20

  17. Polar vs. Nonpolar • Which is polar?

  18. Types of Chemical BondsHydrogen Bonds • Most important bond in Biology • Very weak, but often numerous • H bound to O or N, forms bridge with another electron-hungry atom • Surface Tension of water • Intramolecular bonds • DNA • Proteins Figure 2.9 Figure 2.8

  19. Chemical Reactions Figure 2.10 • Synthesis Rxn – 2+ atoms come together form larger, bond formation, energy absorbing, anabolic rxns in body • Decomposition Rxn – molecule broken down, energy released, catabolic rxns in body • Exchange Rxn – Both synthesis and decomposition, transfer or switch

  20. Factors that Affect Rate of Chemical Rxns

  21. Biochemistry: Inorganic vs. Organic • All molecules of body are either: • Inorganic compounds: small molecules that lack C • Exceptions: CO2, CO • Examples: H2O, salts, most acids and bases • Organic compounds: contain C, large, covalently bonded • Carbohydrates - sugars • Lipids - phospholipids • Proteins – Hemoglobin • Nucleic Acids – DNA, RNA

  22. Inorganic CompoundsWater • Heat Capacity – high heat capacity, absorbs and releases large amounts of heat before temp changes. • Polarity/solvent Properties – because of polarity, excellent solvent. Solvent vs. solute. • Salts, acids, bases dissolve easily in water • Nutrients, gases, waste dissolve easily in water, acts as transport • Chemical Reactivity – Important reactant, digest food or break down of molecules = hydrolysis rxn, water added • Cushioning – Protective function • Cerebrospinal fluid – cushions brain

  23. Inorganic CompoundsSalts • Compound w/ cation and anion (not H+ or OH-) • Dissociate into ions easily in bodily fluids • All salts electrolytes = conduct electrical current in solution • Salts of many metals found in body • Ca2+ and P3- • Na, K in nerve impulses • Fe in hemoglobin Figure 2.11

  24. Inorganic CompoundsAcids and Bases • Both Electrolytes • Acids – sour taste • Proton donors • Dissociation in water yields H+ and anion. • HCl, acetic acid, carbonic acid • Strong acid dissociates completely – HCl • Weak acid dissociates partially – H2CO3 • Bases – bitter taste • Proton acceptors • Dissociation in water yields OH- and cation. • Strong base is strong H+ seeker – OH- • Weak base – HCO3- • When mixed form water and salt • HCl + NaOH -> H2O + NaCl • What kind of reaction is this?

  25. pH: Acid-Base Concentrations • Concentration of H+ in solution measured in pH units • Single unit change of pH is tenfold change • pH 7+ is basic • pH lower than 7 acidic • Body pH regulated by kidneys, lungs, and buffers • Blood pH 7.35-7.45 – what is being carried in blood that is of vital importance? Figure 2.12

  26. Organic Compounds Carbohydrates • Sugars – contain C,H,O • Building blocks of carbs • Glucose primary source of energy ATP • Monosaccharide • Simple sugar • Glucose, Ribose, Deoxyribose • Disaccharide • Double sugars • Dehydration rxn • Glycosidic bond • Maltose, fructose, lactose – must be broken down to enter cell – What kind of rxn? • Polysaccharide • Glycogen - animal • Starch - plant http://chemistry2.csudh.edu/rpendarvis/monosacch.html http://www.mun.ca/biology/scarr/Deoxyribose_versus_Ribose.html

  27. Organic Compounds Lipids • Contain C,H,O • Enter body meats, egg yolks, milk, oils • Insoluble in water, dissolve in other lipids and organic compounds such as alcohol or acetone • Ester bonds • Triglycerides – neutral fats • Glycerol and Fatty Acid tails (can vary) • Saturated – only single bonds, solid at room temp, animal fat • Unsaturated – double bonds, liquid at room temp, plant fat • Trans fats – plant fats solidified, added H. • Omega-3-fatty acids – cold-water fish, decrease heart disease Figure 2.15

  28. Organic Compounds Lipids • Phospholipids – similar to triglycerides • Glycerol and 2 fatty acid tails • Charged Phosphate Head group replaces one tail • Amphipathic • Membranes of cells – generates ability to be selective

  29. Organic Compounds Lipids • Steroids • Flat molecules, 4 ring structure • H,C,O fat soluble • Cholesterol – meats, cheeses, eggs, some made by liver • Cell membranes • Raw material of Vit D • Steroid hormones • Bile salts • Amphipathic

  30. Organic Compounds Proteins • 50% of organic matter in body, most varied function • C,H,O plus N,S • Peptide Bonds • Amino Acids – 20 • Amine group (NH2) and Carboxyl group (COOH) • R group generates variation • Amino Acids joined together to generate polypeptide • Each A.A. is different sequence of A.A. determines shape and function of end protein • Primary, Secondary, Tertiary, Some have Quaternary

  31. Organic Compounds Proteins • Fibrous – structural • Collagen – bones, cartilage, tendons • Keratin – hair, nails, skin • Stable • Globular – functional • Antibodies • Hormones • Transport Proteins • Enzymes • H-bonds essential for structure • Denaturation destroys function • Active Site

  32. Enzymes and Enzyme Activity • Biological Catalysts • Increases rate of rxn w/o becoming part of product or being changed itself • Bind and hold reactants in correct orientation for chemical rxn • Reactants undergo chemical change producing products • Enzymes catalyze millions of rxns a minute • Speed up reactions but determine which reactions proceed at what time • No enzyme no rxn! • Enzymes specific to rxn, often named based on rxn they catalyze – hydrolases, oxidases, galactosidase Figure 2.18

  33. Organic Compounds Nucleic Acids • Blueprint for life, direct growth and development • Composed of C,H,O,N,P • Largest biochemical molecules in body • Building blocks – nucleotides • Nitrogen-containing base • Pentose sugar • Phosphate group • Five bases – pyrimidine or purine Figure 2.19

  34. Organic Compounds Nucleic Acids - DNA • Deoxyribonucleic Acid • 4 bases • Thymine (T) • Adenine (A) • Cytosine (C) • Guanine (G) • Controls genetic info • Found in cell nucleus • Deoxyribose sugar • Double Helix – strands held together via H bonds • Sugar-Phosphate backbone • Bases rungs of ladder • Antiparallel • Replicates during mitosis

  35. Organic Compounds Nucleic Acids - RNA • Ribonucleic Acid • Ribose sugar • 4 bases • Adenine (A) • Cytosine (C) • Guanine (G) • Uracil (U) • Single stranded • Outside nucleus • Multiple functions • mRNA, tRNA, rRNA https://eapbiofield.wikispaces.com/Chapter+6+Molecular+Genetics*

  36. Organic Compounds Nucleic Acids Adenosine Triphosphate - ATP • Stores chemical energy used by all cells • Energy released from glucose breakdown stored in bonds of ATP • Adenine, Ribose, 3 P bound by high energy phosphate bonds • When bond broken, energy released immediately used Figure 2.20a Figure 2.21

  37. The End

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