1. Chemistry Comes Alive
Chapter 2

2. Energy Potential energy: stored energy or energy of position.
Kinetic energy: energy of motion

3. Forms of Energy
Chemical
Thermal/Radiant
Electrical
Mechanical

4. The Composition of Matter

5. Atoms and Chemical Elements
Matter - anything that occupies space and has mass
Atoms - smallest units of matter - have their own distinct properties
Chemical element – a basic chemical substance composed of one type of atom
Unique

6. Atomic Structure Nucleus Electron Shell Protons (+) Neutrons (0)

7. Structure of the Atom

8. Elements of the Human Body

9. Elements Oxygen - O Magnesium - Mg Carbon - C Chlorine - Cl
Hydrogen - H
Nitrogen - N
Calcium - Ca
Phosphorus - P
Sulfur - S
Sodium – Na
Potassium - K
Magnesium - Mg
Chlorine - Cl
Iron - Fe
Iodine - I
Manganese - Mn
Copper - Cu
Zinc - Zn
Cobalt - Co
Fluorine - F

10. Elements (cont’d)
More than 90% of the mass of living things composed of just 4 elements:
Carbon ( C )
Hydrogen (H)
Oxygen (O)
Nitrogen (N)

11. Chemical Bonds

12. Chemical Bonds
Energy relationship between electrons of reacting atoms.
Valence shell – atom’s outermost energy level or that portion that is reactive.
Octet Rule or Rule of 8 – key to chemical reactivity
Reactive and inert elements

14. Ionic Bonds Positive ions and negative ions held together
Electrostatic - forces of attraction
A gain or loss of electrons
Cations - positively charged ions
Anions - negatively charged ions
Unstable in water
Ex. NaCl

15. Ionic Bond

16. Covalent Bond Sharing electrons with other atom Most bonds in body
Strong bonds – not easily broken
Stable in water
H-H
O=O

17. Single Covalent Bond

18. Covalent Bonds

19. Hydrogen Bonds Weak bonds between hydrogen and a weak negative charge
In large numbers they provide strength within molecules
Important in DNA
Common in water

20. Hydrogen Bonding in Water

21. Hydrogen Bonds in DNA

22. Chemical Reactions

23. Synthesis Reactions AB  A + B
Requires formation of new bonds between combining units (reactants)
Important - repairing worn or damaged parts.
Anabolism - synthesis reactions within the cell

24. Decomposition Reactions
A + B  AB
Breaking down of molecules into simpler molecules
Digestion
Catabolism - decomposition reactions within the cell

25. Exchange or Displacement Reactions
AB + C  AC + B
AB + CD AD + CB
Involve both synthesis and decomposition
Ex. ATP transfers phosphate group to glucose

26. Oxidation-Reduction Decomposition, plus exchange of electrons.
Reactant losing electrons or H atom – oxidized
Reactant gaining electrons or H atom– reduced
“OIL RIG”
Not always a complete transfer of electrons
Ex. Cellular respiration

27. Reversibility All chemical reactions theoretically reversible.
Many biological reactions go in one direction
Energy is lost
Removal of reaction products

28. Factors Influencing Rate of Chemical Reactions
Temperature – higher  quicker
Particle size – smaller  faster
Concentration – higher  faster
Catalysts – increase rate of reaction w/o themselves becoming chemical changed
Enzymes

29. Chemical compounds of the cell

30. Inorganic Compounds Generally lack carbon (exception CO2)
Tend to be simpler and smaller molecules than organic

31. Inorganic Compounds (cont’d)
Water

32. Inorganic Compounds (cont’d)
Water
Makes up about 60-70% of total body mass
The universal solvent (a medium that dissolves a solute)
Important transport medium
Has a high heat capacity - absorbs and releases heat slowly

33. Inorganic Compounds (cont’d)
Water (cont’d)
High heat of vaporization – helps to cool body
Important reactant
Effective lubricant
Cushions organs

34. Inorganic Compounds (cont’d)
Salt
Dissolves or ionizes when placed in water - dissociates
All are electrolytes - can conduct an electric current

35. Inorganic Compounds (cont’d)
Acids and Bases
Acids – when dissolved in water, release one or more hydrogen ions
pH < 7
Bases - reduce the concentration of hydrogen ions in a solution (bind w/ H+ ions)
pH >7

36. pH scale

37. Inorganic Compounds (cont’d)
Acids and Bases (cont’d)
When acids and bases are mixed – neutralization
Form water and salt
Buffer – regulate acid-base balance in body

38. Organic Molecules Carbon containing compounds
All fairly large, covalently bonded molecules
All synthesized by dehydration synthesis and decomposed by hydrolysis.

40. Organic Molecules (cont’d)
Carbohydrates
Sugars & starches
Energy source – readily easy source of fuel
Monosaccharide - simple sugar (glucose)
Disaccharide – double sugar (table sugar - sucrose)
Polysaccharide - lack sweetness
Longer term energy storage
Glycogen - synthesized by animals. Stored in liver and muscles.

42. Organic Molecules (cont’d)
Lipids
Do not dissolve in water
Fats
Must be broken down by body before used
Solid or liquid
Saturated or unsaturated
Provide insulation and reserve body fuel

43. Organic Molecules (cont’d)
Lipids (cont’d)
Phospholipid – plasma membrane
Steroids
Cholesterol (produced by liver)
Cell membranes
Vitamin D synthesis
Production of steroid hormones

44. Organic Molecules (cont’d)
Proteins
Made up of amino acids
Covalent bond between 2 amino acids form peptide bonds
Chain of 10 or more amino acids = polypeptide
One or more polypeptide = protein

45. Organic Molecules (cont’d)
Proteins (cont’d)
Function
Basic structural material of body
Enzyme – biological catalyst – increase rate of chemical reaction – decrease activation energy

46. Organic Molecules (cont’d)
Nucleic Acids
DNA
Contain nucleotides: deoxyribose sugar, nitrogen bases (T, A, C, G), phosphate group
Double helix
Directs protein synthesis

47. Organic Molecules (cont’d)
Nucleic Acids (cont’d)
RNA
Nucleotides: Ribose sugar, nitrogen bases (U, A, C, G), phosphate group
Carries out protein synthesis

48. Organic Molecules (cont’d)
ATP
Universal energy compound used by all cells of the body
Energy released by oxidation of glucose (in cellular respiration) and captured in bonds of ATP for later use