1. Basic Chemistry

2. Matter and Energy
Matter—anything that occupies space and has mass (weight)
Energy—the ability to do work
Chemical
Electrical
Mechanical
Radiant

3. Composition of Matter Elements—fundamental units of matter
96% of the body is made from four elements
Atoms—building blocks of elements

4. Atomic Structure Nucleus Protons (p+) Neutrons (n0) Outside of nucleus
Electrons (e-)
Figure 2.1

5. Atomic Structure of Smallest Atoms
Figure 2.2

6. Identifying Elements
Atomic number
Atomic mass

7. Isotopes and Atomic Weight
Have the same number of protons
Vary in number of neutrons
Figure 2.3

8. Isotopes and Atomic Weight
Close to mass number of most abundant isotope
Atomic weight reflects natural isotope variation

9. Radioactivity Radioisotope Heavy isotope Tends to be unstable
Decomposes to more stable isotope
Radioactivity—process of spontaneous atomic decay

10. Molecules and Compounds
Molecule—two or more like atoms combined chemically
Compound—two or more different atoms combined chemically
Figure 2.4

11. Chemical Reactions Atoms are united by chemical bonds
Atoms dissociate from other atoms when chemical bonds are broken

12. Electrons and Bonding
Electrons occupy energy levels called electron shells
Electrons closest to the nucleus are most strongly attracted
Each shell has distinct properties

13. Electrons and Bonding
Bonding involves interactions between electrons in the outer shell (valence shell)
Full valence shells do not form bonds

14. Inert Elements
Atoms are stable (inert) when the outermost shell is complete
How to fill the atom’s shells
Shell 1
Shell 2
Shell 3

15. Inert Elements
Atoms will gain, lose, or share electrons to complete their outermost orbitals and reach a stable state
Rule of eights
Atoms are considered stable when their outermost orbital has 8 electrons
The exception to this rule of eights is Shell 1, which can only hold 2 electrons

16. Inert Elements
Figure 2.5a

17. Reactive Elements Valence shells are not full and are unstable
Tend to gain, lose, or share electrons
Allow for bond formation, which produces stable valence
Figure 2.5b

18. Chemical Bonds Ionic bonds
Form when electrons are completely transferred from one atom to another
Ions
Charged particles
Anions
Cations
Either donate or accept electrons
PLAY
Ionic Bonds

19. + – Ionic Bonds Na Cl Na Cl Sodium atom (Na) (11p+; 12n0; 11e–)
Chlorine atom (Cl) (17p+; 18n0; 17e–)
Sodium ion (Na+)
Chloride ion (Cl–)
Sodium chloride (NaCl)
Figure 2.6

20. Chemical Bonds Covalent bonds
Atoms become stable through shared electrons
Single covalent bonds share one pair of electrons
Double covalent bonds share two pairs of electrons
PLAY
Covalent Bonds

21. Examples of Covalent Bonds
Figure 2.7a

22. Examples of Covalent Bonds
Figure 2.7b

23. Examples of Covalent Bonds
Figure 2.7c

24. Polarity Covalently bonded molecules Some are non-polar
Electrically neutral as a molecule
Some are polar
Have a positive and negative side
Figure 2.8

25. Chemical Bonds Hydrogen bonds Weak chemical bonds
Hydrogen is attracted to the negative portion of polar molecule
Provides attraction between molecules

26. Hydrogen Bonds
Figure 2.9

27. Patterns of Chemical Reactions
Synthesis reaction
Atoms or molecules combine
Energy is absorbed for bond formation
Decomposition reaction
Molecule is broken down
Chemical energy is released
PLAY
Disaccharides

28. Synthesis and Decomposition Reactions
Figure 2.10a

29. Synthesis and Decomposition Reactions
Figure 2.10b

30. Patterns of Chemical Reactions
Exchange reaction
Involves both synthesis and decomposition reactions
Switch is made between molecule parts and different molecules are made

31. Patterns of Chemical Reactions
Figure 2.10c

32. Biochemistry: Essentials for Life
Organic compounds
Contain carbon
Most are covalently bonded
Example:
Inorganic compounds
Lack carbon
Tend to be simpler compounds

33. Important Inorganic Compounds
Water
Most abundant inorganic compound
Vital properties
High heat capacity
Polarity/solvent properties

34. Important Inorganic Compounds
Salts
Easily dissociate into ions in the presence of water
Vital to many body functions
Include electrolytes which conduct electrical currents

35. Dissociation of a Salt in Water
Figure 2.11

36. Important Inorganic Compounds
Acids
Release hydrogen ions (H+)
Are proton donors
Bases
Release hydroxyl ions (OH–)
Are proton acceptors
Neutralization reaction
Acids and bases react to form water and a salt

37. pH Measures relative concentration of hydrogen ions pH 7 = neutral
pH below 7 = acidic
pH above 7 = basic
Buffers—chemicals that can regulate pH change
Figure 2.12

38. Important Organic Compounds
Carbohydrates
Contain carbon, hydrogen, and oxygen
Include sugars and starches
Classified according to size
Monosaccharides
Disaccharides
Polysaccharides

39. Carbohydrates
PLAY
Disaccharides
Figure 2.13a–b

40. Carbohydrates
PLAY
Polysaccharides
Figure 2.13c

41. Carbohydrates
Figure 2.14

42. Important Organic Compounds
Lipids
Contain carbon, hydrogen, and oxygen
Carbon and hydrogen outnumber oxygen
Insoluble in water

43. Lipids Common lipids in the human body Neutral fats (triglycerides)
Found in fat deposits
Composed of fatty acids and glycerol
Source of stored energy
PLAY
Lipids

44. Lipids
Figure 2.15a

45. Lipids Common lipids in the human body (continued) Phospholipids
Steroids

46. Lipids
Figure 2.15b

47. Lipids Cholesterol The basis for all steroids made in the body
Figure 2.15c

48. Important Organic Compounds
Proteins
Made of amino acids
Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur
Figure 2.16

49. Proteins Account for over half of the body’s organic matter
Provide for construction materials for body tissues
Play a vital role in cell function

50. Proteins Amino acid structure Contain an amine group (NH2)
Contain an acid group (COOH)
Vary only by R groups

51. Proteins Fibrous proteins Also known as structural proteins
Appear in body structures
Examples include collagen and keratin
Stable
Figure 2.17a

52. Proteins Globular proteins Also known as functional proteins
Function as antibodies or enzymes
Can be denatured
Figure 2.17b

53. Enzymes Act as biological catalysts
Increase the rate of chemical reactions
Figure 2.18a

54. Enzymes
PLAY
Chemistry of Life® Enzymes Animation
Figure 2.18b

55. Important Organic Compounds
Nucleic Acids
Provide blueprint of life
Nucleotide bases
A = Adenine
G = Guanine
C = Cytosine
T = Thymine
U = Uracil
Make DNA and RNA
Figure 2.19a

56. Nucleic Acids Deoxyribonucleic acid (DNA)
Organized by complimentary bases to form double helix
Replicates before cell division
Provides instructions for every protein in the body
Figure 2.19c

57. Important Organic Compounds
Adenosine triphosphate (ATP)
Chemical energy used by all cells
Energy is released by breaking high energy phosphate bond
ATP is replenished by oxidation of food fuels

58. Adenosine Triphosphate (ATP)
Figure 2.20a