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Biochemistry

Biochemistry. All Matter is composed of Atoms. The Structure of the Atom. Electrons: Negative electrical charge. Protons: Positive electrical charge. Neutrons: No net electrical charge. Molecules. Two or more atoms held together by Chemical bonds. Chemical Bonds.

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Biochemistry

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  1. Biochemistry

  2. All Matter is composed ofAtoms

  3. The Structure of the Atom Electrons: Negative electrical charge Protons: Positive electrical charge Neutrons: No net electrical charge

  4. Molecules • Two or more atoms held together by Chemical bonds

  5. Chemical Bonds • form because of the interactions between the electrons of the atoms

  6. The atom’s ELECTRONEGATIVITY(ability to attract electrons) • Determines the type and strength of the Chemical bond

  7. Ions • Ions are atoms that have either a positive or negative electrical charge because the electron number is NOT equal to the proton number

  8. IONIC BONDS • Form between atoms when electrons are TRANSFERED from one atom to another forming ions of opposite electronic charges • http://www.dac.neu.edu/physics/b.maheswaran/phy1121/data/ch09/anim/anim0904.htm

  9. Covalent Bonds • Form when atoms share electrons • Occur when the electronegativities between the atoms are similiar • http://www.dac.neu.edu/physics/b.maheswaran/phy1121/data/ch09/anim/anim0904.htm

  10. Some molecules have Single Covalent Bonds… which means the atoms share one pair (a single pair) of electrons

  11. Some molecules have Double Covalent Bonds… which means the atoms share two pairs of electrons

  12. Some molecules have Triple Covalent Bonds… which means the atoms share Three pairs of electrons

  13. Nonpolar Covalent Bonds • Occur when the electronegativities of both atoms are identical and the electrons are shared equally

  14. Polar Covalent Bonds • Occur when the electronegativities of both atoms are Different and the electrons are shared unequally Negative Pole Positive Pole

  15. Hydrogen Bonds • Hydrogen bonds are weak bonds which form between molecules Hydrogen Bond

  16. Bond Strengths • Ionic Bonds are weak and are easily broken in water • Covalent Bonds are generally strong • Hydrogen Bonds are very weak

  17. The Properties of Water • 1. Water is the Universal Solvent. • Ionic compounds and Polar covalent molecules readily dissolve in water

  18. Hydrophilic Molecules (water-loving) • Are substances that dissolve in water…. Salts, sugars, etc….

  19. Hydrophobic Molecules (water-fearing) • Are substances that do not dissolve in water… oils, waxes, etc…

  20. Water Has A High Specific HeatCapacity…. The capacity of a substance to change temperature in response to a gain or loss of heat… water changes temperatures very slowly • Specific Heat - the amount of heat needed to raise 1 g of the substance 1 degree C. • Why? ……… Hydrogen bonding.

  21. Water Has A High Heat Of Vaporization • Heat of Vaporization: the quantity of heat a liquid must absorb for 1g of it to convert to a gaseous state.

  22. Liquid Water Is Cohesive • Water sticks to water. • Why? Because the polarity of water results in hydrogen bonding.

  23. Liquid Water is Adhesive • Water sticks to other molecules. • Why? Hydrogen bonding.

  24. Water transport in trees uses Cohesion and Adhesion

  25. Water Has A High Surface Tension • The surface of water is difficult to stretch or break. • Why? • Hydrogen bonding.

  26. Water Stabilizes Temperature • Water can absorb and store a huge amount of heat from the sun. • Result - climate moderation • Result - organisms are able to survive temperature changes.

  27. Evaporative Cooling

  28. Result: • Water cools organisms from excessive heat buildup. • Why? As water evaporates it takes the heat with it.

  29. Water Expands and becomes less dense when It Freezes….so it floats • The distance between water molecules INCREASES from the liquid to the solid form. • Why? • Hydrogen bonding

  30. Water Benzene Floats Sinks

  31. Result • Ice floats and forms an blanket of insulation during the winter……….Aquatic life can live under ice.

  32. Water is used to make Solutions • A Solution is a Homogeneous mixture of two or more substances. • Solvent + Solute Solution • Sugar water, Saltwater, Pepsi

  33. Solvent • The dissolving agent • Present in a greater proportion Examples: • Water • Methane

  34. Solute • The substance that is dissolved. • Present in smaller quantity Examples: • Salt in saltwater • Sugar in sugar water

  35. Solution Concentration • Usually based on Molarity • Molarity - the number of moles of solute per liter of solution. • A mole is = 6.021x1023

  36. One Mole of each Sugar Copper Sulfate Sulfur Mercury Oxide Sodium Chloride Copper

  37. Dissociation of Water • Water can sometimes split into two ions. • In pure water the concentration of each ion is 10-7 M

  38. Adding certain solutes disrupts the balance between the two ions. • The two ions are very reactive and can drastically affect a cell.

  39. Acids • Materials that can release H+ Example: HCl HCl H+ + Cl- Hydrochloric acid, vinegar, etc…

  40. Effects of Acid Rain

  41. Bases • Materials that can absorb H+ • Often reduce H+ by producing OH- Example: NaOH NaOH Na+ + OH- Drano, Soaps, etc…….

  42. pH Scale • A logarithmic scale for showing H+ concentration in a solution. pH = - log [H+]

  43. pH Scale Acids: pH < 7 Neutral: pH 7 Bases: pH >7

  44. Acids: pH <7 etc. • Bases: pH >7 etc. Each pH unit is a 10x change in H+

  45. Buffers • Materials that have both acid and base properties. • Resist pH shifts. • Cells and other biological solutions often contain buffers to prevent damage.

  46. Organic Molecules • Contain carbon atoms, exceptions are carbon monoxide and carbon dioxide • Carbon has 4 electrons available to form 4 chemical bonds….therefore large molecules are easily formed using carbon as the backbone. • Large carbon based molecules are usually found as long chains or rings.

  47. Macromolecules • Most macromolecules are “polymers” ….molecules that consist of a single unit (monomer) repeated many times.

  48. Functional Groups • Many organic molecules share similar properties because they have similar clusters of atoms, called the….. Function Groups • Each Functional Group gives the molecules a particular property, such as acidity or polarity.

  49. Functional Groups

  50. Four Main Types Of Macromolecules • Carbohydrates • Lipids • Protein • Nucleic acids

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