Molecular Interactions

1. Molecular Interactions Or, Chemistry class in one lecture! Key Concepts • Elements, Atoms, Isotopes etc. • Chemical formulas, Chemical bonds • pH scale, acids/bases • Organic Chemistry / Biochemistry

2. Element = Building block of matter • In human: 11 major essential elements • C, O, H • Trace Elements (in smaller amounts but still essential) • Na, Se, P, Mg, Mn, K, Ca, Fe

3. Structure of Atoms(AKA elements) • Some Terminology for you to know: • Isotope • Atomic Number • Atomic Mass • Ion

4. Isotopes = Atoms of an element that have different numbers of neutrons. Same Atomic Number, variable Atomic Mass Much rarer Most common Heavy water = ?

5. Some isotopes are unstable: Radioisotopes 3 types of radiation: •  radiation – An alpha particle is made up of two protons and two neutrons bound together. • Generally not dangerous to life unless inhaled or ingested • Does not travel far

6. Some isotopes are unstable: Radioisotopes radiation - In beta decay, a neutron in the nucleus spontaneously turns into a proton, an electron, and a third particle called an antineutrino. The nucleus ejects the electron and antineutrino, while the proton remains in the nucleus. The ejected electron is referred to as a beta particle. • Relatively harmless • Medium penetrating power • Can mutate DNA if struck • Used to kill cancer cells

7. Nuclear Medicine: use of radioisotopes in diagnosis & treatment of disease. 127I is “normal” iodine 131I has 4 extra neutrons  and  radiation

8. Radioisotopes -radiation • In spontaneous fission, an atom actually splits instead of throwing off an alpha or beta particle. • Gamma rays are made of energy, not moving particles like alpha and beta particles. • Gamma Radiation can penetrate thick material • Since Gamma Radiation is more penetrating it can cause the most damage to the human body • Gamma knife • Used for benign or malignant tumors of the brain

9. Alpha radiation consists of helium-4nucleus and is readily stopped by a sheet of paper. Beta radiation, consisting of electrons, is halted by an aluminium plate. Gamma radiation is eventually absorbed as it penetrates a dense material. Lead is good at absorbing gamma radiation, due to its density.

10. http://www.youtube.com/watch?v=3u_8frR0IpE

11. http://www.youtube.com/watch?v=rvAJ_u3Q0Hw&feature=related

12. The Chemistry of Life • Elements = Atoms • Nucleus • Protons • Neutrons • Orbit • Electrons

14. Atoms Atoms must be neutral Atoms/molecules that are stable will not bond with other atoms/molecules. • Atomic number • The number of protons, usually also equals the number of electrons. • Atomic mass • The sum of the number of neutrons and protons in the nucleus.

15. Shells or Orbits Each electron shell can hold a specific number of electrons • Shell 1 = 2e • Shell 2 = 8e • Shell 3 = 18e

17. Electron Bonding • Outermost shell contains all pairs of electrons • Stable • Outermost shell contains at least one unpaired electron • Unstable • Lose, gain or share electrons to become stable • An atom is most stable when each electron is paired!

18. Chemical Bonds • Ionic: electrons pulled from one atom to another: Na+ and Cl- • Covalent: electrons shared equally • Hydrogen: weak attraction between H atoms and O, N, and Fl. • Causes surface tension in water. • Van der Waal’s forces: weak attractions between nuclei of atoms

19. Chemical Bonds • Ions • More (or less) electrons than protons • Ionic Bonds • Anions • Negative • Cations • Positive

20. Ionic Bonds • Give away or receive electrons to create ions and for each ion to become more stable • Ions of opposite charge bind with each other to form an ionic bond • An ionic bond typically includes a metal • NaCl

21. Ionic Bonding

22. Important Ions in Physiology cations anions

23. Chemical Bonds • Covalent • Polar • Non-polar

24. Covalent Bonds • Strong bonds that occur when two atoms share electrons in order to become more stable

25. Covalent Bonds • Non-polar Covalent Bonds • If the electrons are shared equally between atoms • Polar Covalent Bonds • If electrons spend more time around one atom than the other • Molecules develop regions of partial positive and negative charges

26. Covalent Bonds

27. http://www.youtube.com/watch?v=QqjcCvzWwww

28. Polar Covalent Bond: Water The electrons are shared equally If two electrons are shared, that is a “double bond.”

29. Polar covalent molecules Non-polar covalent molecules Consequence: ions and polar molecules dissolve well in water Are call Electrolytes

30. Chemical Bonds • Hydrogen Bonds • Surface tension • Attractive force between water molecules that causes water to form spherical droplets • Quickly forms and quickly breaks

31. Reactions • Types of Reactions • Synthesis Reaction--Anabolic • A + B C • Decomposition Reaction--Catabolic • AB A + B • Exchange Reaction • AB + C AC + B

32. Chemical Reactions • Reactants form Products • First Type of Reaction • Anabolic or Synthesis Reaction

34. Chemical Reactions • Decomposition Reaction • Catabolic

36. Acid Base Reactions Acids • The concentration Hydrogen ions free in solution • Protons • H+ • Bases • Are proton acceptors • Bind with hydrogen ions • Hydroxyl ion = OH- • Bicarbonate ion = HCO3-

38. Buffers • Buffers resist abrupt and large swings in the pH of body fluids. • To resist large changes in pH, the body releases hydrogen ions when the pH rises and binds hydrogen ions with bicarbonate ions when the pH drops. • Blood pH = 7.35 – 7.45

39. Buffers • CO2 + H2O H2CO3 H++ HCO3-

40. End of Inorganic Chemistry

41. BIOMOLECULES • Carbohydrates • Fats • Proteins

42. Organic Compounds • Carbohydrates • A group that includes things like table sugars and starches. • Includes Simple and Complex groups

43. Simple Carbohydrates • Simple • Monosaccharides • Fructose • Glucose • Disaccharides • Sucrose • Lactose

44. Monosaccharides

45. Disaccharides

46. Simple Carbohydrates • Examples • Candy Bar • Soda • Table Sugar • Fruit • Cake

47. Complex Carbohydrates • Examples • Wheat • Rice • Corn • Cellulose • Potato

48. Polysaccharide

49. OrganicCompounds • Complex Carbohydrates • Polysaccharides are long branching chains of glucose molecules. • Starch is a carbohydrate stored in plants. • Glycogen is a storage carbohydrate in animals. • Stored in liver and all muscle types

50. Lipids • 4 categories: • Fatty Acids can be (un)saturated • Mono-, di-, and triglycerides • Phospholipids (polar) • Steroids • Eicosanoids (prostaglandins)