1. CH. 2 Basic Chemistry

2. Types of Energy Types of energy:
Kinetic: energy associated with motion
Potential: stored (inactive) energy
Electrical : results from the movement of charged particles (Na+, K+)

3. Matter and Composition of Matter
Matter is anything that has mass and occupies space
Matter is made up of elements
Elements are pure substances that cannot be broken down by ordinary chemical means; composed of atoms

4. The Atomic Structure N Atoms Have Three Important Particles:
Neutrons
No charge, in atomic nucleus
1 atomic mass unit (amu)
Protons
Positive charge, in atomic nucleus
1 amu
Electrons
Negative charge, orbit nucleus (in up to 7 shells)
0 amu
Equal in number to protons in atom N

5. Identifying Elements
Atoms of each element contain a unique number of protons
Compare hydrogen, helium and lithium
The atomic number is equal to the number of protons
The mass number is equal to the number of protons and neutrons

6. Hydrogen (H) Helium (He) Lithium (Li) Proton Neutron Electron
Figure 2.2

7. Chemical Bonds
A molecule is two or more atoms chemically bound together (H2 or C6H12O6)
Octet rule: Except for the first shell which is full with two electrons, atoms interact in order to have eight electrons in their outermost energy level or valence shell

8. (a) Chemically inert elements
Valence shell complete 8e 2e 2e
Helium (He)
Neon (Ne)

9. Chemically Reactive Elements
Atoms whose valence shell is not fully occupied by electrons with interact with other atoms forming a chemical bond.
To form a chemical bond, atoms lose, gain or share electrons with other atoms to achieve stability

10. (b) Chemically reactive elements
Valence shell incomplete 4e 1e 2e
Hydrogen (H)
Carbon (C) 1e 6e 8e 2e 2e
Oxygen (O)
Sodium (Na)
Figure 2.4b

11. Oppositely charged ions are attracted resulting in an ionic bond
Ionic Bonds
Ions are formed by:
The loss or gain of electrons
Anions (–) have gained one/more electrons
Cations (+) have lost one/more electrons
Oppositely charged ions are attracted resulting in an ionic bond

12. + – Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+)
Chloride ion (Cl–)
Sodium chloride (NaCl)
Figure 2.5

13. Covalent Bonds
Covalent bonds form when valence electrons are shared
Allows each atom to fill its valence shell at least part of the time

14. + Reacting atoms Resulting molecules or Hydrogen atoms Carbon atom
Molecule of
methane gas (CH4)
(a) Formation of four single covalent bonds:
Figure 2.7a

15. + Reacting atoms Resulting molecules or Oxygen atom Oxygen atom
Molecule of
oxygen gas (O2)
(b) Formation of a double covalent bond:
Figure 2.7b

16. + Reacting atoms Resulting molecules or Nitrogen atom Nitrogen atom
Molecule of
nitrogen gas (N2)
(c) Formation of a triple covalent bond:.
Figure 2.7c

17. Sharing of electrons may be equal or unequal
Covalent Bonds
Sharing of electrons may be equal or unequal
Equal sharing of valence electrons produces nonpolar covalent bonds

18. Covalent Bonds
Unequal sharing of valence electrons by atoms with different electron-attracting abilities produces polar covalent bonds
Ex. H2O

19. + –
Hydrogen bond + + – – – + + + –
(a) The slightly positive ends (+) of the water molecules become aligned with the slightly negative ends (–) of other water molecules.
Attractive force between a positive hydrogen of one molecule and an electronegative atom of another molecule
Figure 2.8

20. Synthesis Reactions A + B  AB Always involve bond formation Anabolic
Endergonic

21. (a) Synthesis reactions
Smaller particles are bonded
together to form larger,
molecules.
Example
Amino acids are joined to
Form protein.
Amino acid
molecules
Protein
molecule
Figure 2.9a

22. Decomposition Reactions
AB  A + B
Opposite of synthesis reactions
Involves breaking bonds
Catabolic
Exergonic

23. (b) Decomposition reactions
Bonds are broken in larger
molecules, resulting in smaller,
less complex molecules.
Example
Glycogen is broken down to release
glucose units.
Glycogen
Glucose
molecules
Figure 2.9b

24. Classes of Compounds Inorganic compounds Organic compounds
Do not contain carbon (ex. Water, salts, and many acids and bases)
Organic compounds
Contain carbon, usually large, covalently bonded (ex’s. carbohydrates, fats, proteins, nucleic acids)

25. Water
60%–80% of the volume of living cells
Most important inorganic compound in living organisms because of its properties

26. Salts
Ionic compounds that dissociate into ions in water
Ions (electrolytes) conduct electrical currents in solution

27. Acids : Proton (H+) donors (release H+ in solution)
HCl  H+ + Cl–

28. Bases: Proton acceptors (take up H+ from solution)
NaOH  Na+ + OH–

29. Acid-Base Concentration
Acid solutions contain higher amounts of H+
As [H+] increases: acidity increases
Basic solutions contain higher concentrations of OH–
As [H+] decreases (or as [OH–] increases): alkalinity increases
pH = measure of the acidity/bascisity of a solution

30. Acid-Base Concentration
Neutral solutions:
pH = 7
Contains equal numbers of H+ and OH–
Acidic solutions
 [H+],  pH
pH = 0–6.99
Basic solutions
 [H+],  pH
pH= 7.01–14

31. Ribonucleic Acid (RNA)
Four bases:
adenine (A), guanine (G), cytosine (C), and uracil (U)
Single-stranded
PLAY
Animation: DNA and RNA

32. Adenosine Triphosphate (ATP)
Adenine-containing RNA nucleotide with two additional phosphate groups

33. High-energy phosphate bonds can be hydrolyzed to release energy.
Adenine
Phosphate groups
Ribose
Adenosine
Adenosine monophosphate (AMP)
Adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)
Figure 2.19

34. Function of ATP Phosphorylation:
The chemical energy contained in the high energy phosphate bonds can be used to perform cellular work

35. Figure 2.20 Solute + Membrane protein (a) Transport work +
Relaxed smooth
muscle cell
Contracted smooth
muscle cell
(b)
Mechanical work +
(c)
Chemical work
Figure 2.20

36. Carbohydrates Functions Polymers of monosaccharides Three classes
Monosaccharides -Simple sugars containing three to seven C atoms
Ex. Glucose
Disaccharides -Double sugars
fructose, sucrose, maltose
Polysaccharides –many monosaccharides linked together ex., starch, glycogen, cellulose
Functions
Cellular fuel
Provide structure in RNA and DNA

37. Carbohydrates: Polysaccharides

38. Lipids Mainly insoluble in water Several Classes of Lipids
Triglycerides
Phospholipids
Steroids

39. Triglycerides Triglycerides—solid fats and liquid oils
Three fatty acids bound to glycerol (3:1)
Functions
Energy storage
Insulation
Protection

40. Phospholipids
Two fatty acids bound to glycerol (2:1), bound to a phosphate group
“Head” and “tail” regions have different properties
Main component of cellular membranes

41. Steroids Composed of four fused carbon rings
Ex’s. Cholesterol, vitamin D, steroid hormones, and bile salts

42. Polymers of amino acids All 20 amino acids have same basic structure
Proteins
Polymers of amino acids
All 20 amino acids have same basic structure
Amino acids are held together by peptide bonds (polypeptides)

43. Denaturing Natural Folding
(protein folding animation 2m 19 s) start around 1:11

44. Nucleic Acids Two examples: DNA and RNA Contain C, O, H, N, and P
Polymers of nucleotides: nucleotides have 3 parts: a N-containing base, a pentose sugar, and a phosphate group

45. Sugar-phosphate backbone
Nucleotide
Base
pair
Base pair
Figure 3.16C DNA double helix.
Sugar-phosphate backbone

46. Deoxyribonucleic Acid (DNA)
Four bases:
adenine (A), guanine (G), cytosine (C), and thymine (T)
Double-stranded, helical
Replicates before cell division, ensuring genetic continuity
Provides instructions for protein synthesis

47. Ribonucleic Acid (RNA)
Four bases:
adenine (A), guanine (G), cytosine (C), and uracil (U)
Uracil replaces thymine in RNA
Single-stranded
Mainly active outside of nucleus