1. Lesson Overview
2.1 The Nature of Matter

2. Atoms What three subatomic particles make up atoms?
Protons – in nucleus, positive charge
Neutrons – in nucleus, neutral-no charge
Electrons – outer shell, negative charge
QUESTION: What overall charge does
the nucleus have?

3. Elements and the Periodic Table
pure substance that consists entirely of one type of atom
Found on Periodic Table, represented by one- or two-letter symbols
Atoms of element MUST have same number of protons (atomic number); can differ in number of electrons (ions) or neutrons (isotopes)

4. Elements and the Periodic Table
ATOMIC NUMBER - # of protons in the nucleus of an atom (equal to # of electrons in neutral atom)
MASS NUMBER – Number of protons and neutrons combined
* To get # of neutrons, SUBTRACT
atomic number from mass
number

5. Elements and the Periodic Table
EXAMPLE:
What atom is shown to the right?
How do you know?
What is its atomic number?
What is the mass number?
What are the number of protons?
What are the number of electrons?
What are the number of neutrons?

6. Isotopes
ISOTOPES - Atoms of the same element that differ in the number of neutrons they contain
So isotopes of an elements have different MASS NUMBERS
Isotopes have the same chemical properties (same # of electrons)

7. Radioactive Isotopes
Some isotopes are radioactive, meaning that their nuclei are unstable and break down at a constant rate over time.
Radioactive isotopes have a number of important scientific and practical uses.
Radioactive dating to determine the ages of rocks and fossils
Used to detect and treat cancer
Used as labels or “tracers”

8. Chemical Compounds
Chemical compound - formed by the chemical combination of two or more elements in definite proportions
Compounds represented by chemical formula
Example:
Water Salt
properties of a compound different from elements

9. Chemical Bonds Bonds involve the electrons of atoms Two main types:
Ionic bonds – transfer of electrons, forming ions (charged atoms) – one positive (cation) and one negative (anion)
Example: NaCl
Covalent bonds – sharing of electrons, complete outer shell; form MOLECULES
Example: water

10. Ionic Bonds

11. Covalent Bonds

12. Lesson Overview
2.2 Properties of Water

13. The Water Molecule
How does the structure of water contribute to its unique properties?
Because water is a polar molecule, it is able to form multiple hydrogen bonds, which account for many of water’s special properties.

14. Polarity oxygen end = slight (-) charge
hydrogen end = slight (+) charge
A molecule in which the charges are unevenly distributed is said to be “polar”

15. Hydrogen Bonding OPPOSITES ATTRACT!
hydrogen bond – attraction between (+) hydrogen and (-) oxygen
hydrogen bonding important to water’s special properties
Cohesion
Heat capacity

16. Cohesion, Adhesion, and Heat Capacity
Cohesion - attraction between
molecules of the same substance.
(surface tension) Sticky
Adhesion – attraction between
molecules of different substances
(capillary action)
Meniscus
Heat Capacity - amount of heat
energy required to increase its
temperature

17. Solutions Solute—the substance that is dissolved
Solvent—the substance in which the solute dissolves; water known as “universal solvent”
*Water’s polarity gives it the ability to dissolve both ionic compounds and other polar molecules (salts, sugars, minerals, gases)
Suspensions - mixtures of water and undissolved material
**Example for solution and suspension - BLOOD

18. Acids, Bases, and pH
Water molecules sometimes split apart to form hydrogen ions and hydroxide ions (DISSOCIATION of WATER)

19. The pH Scale
pH scale - indicates the concentration of H+ ions in solution
Ranges from 0 to 14
pH of 7 = neutral (equal # of H+ and OH-)
below 7 = acidic (more H+ than OH-)
above 7 = basic, or alkaline (more OH- than H+)

20. The pH Scale
Each step on the pH scale represents a factor of 10. For example, a liter of a solution with a pH of 4 has 10 times as many H+ ions as a liter of a solution with a pH of 5.

21. Lesson Overview
2.3 Carbon Compounds

22. The Chemistry of Carbon
What do we know about CARBON?
Symbol
Atomic number
Number of valence electrons
***Living organisms are made up of molecules that consist of CHONPS

23. Macromolecules
The smaller units, or monomers, join together to form polymers.
The monomers in a polymer may be identical or different.

24. Macromolecules 1. carbohydrates 2. lipids 3. nucleic acids 4. proteins
Four major groups of macromolecules found in living things:
1. carbohydrates
2. lipids
3. nucleic acids
4. proteins

25. Carbohydrates made up of CHO usually in a ratio of 1 : 2 : 1.
Functions –
main source of energy
structural purposes
Examples:
glucose (monosaccharide/monomer)
starch (polysaccharide/polymer)

26. Lipids Made mostly of C & H’s and are generally not soluble in water
Examples are fats, oils, waxes, and steroids
Functions:
Used to store energy (fat)
Parts of biological membranes (phospholipids)
waterproof coverings (waxes)
chemical messengers (steroids/hormones)

27. Lipids Most are made up of glycerol and fatty acid chains
Saturated vs. Unsaturated

28. Nucleic Acids made up of CHONP
Nucleotides consist of three parts: a 5-carbon sugar, a phosphate group (–PO4), and a nitrogenous base.
Functions:
to store and transmit genetic information
***Two kinds – DNA and RNA

29. Protein
made up of CHON
monomer is an amino acid (a.a. come together to make proteins)
Functions:
Varied functions
controlling the rate of reactions
regulating cell processes
forming cellular structures
transporting substances into or out of cells
helping to fight disease

30. Protein
Amino acids have an amino group (–NH2), a carboxyl group (– COOH); R-group make each a.a. different
Covalent bonds called peptide bonds link amino acids together to form a polypeptide

31. Levels of Organization
Proteins have four levels of structure.
1. Primary structure is the sequence of its amino acids
2. Secondary structure is the folding or coiling of the polypeptide chain. (alpha/beta)
3. Tertiary structure is the 3-D structure
4. Quatenary structure – subunits come together

32. 2.4 Chemical Reactions and Enzymes
Lesson Overview
2.4 Chemical Reactions and Enzymes

33. Chemical Reactions
Ex.
The elements or compounds that enter into a chemical reaction are known as reactants.
The elements or compounds produced by a chemical reaction are known as products.

34. Activation Energy
Activation Energy - the energy that is needed to get a reaction started
The difference between the required energy and the energy of the reactants is the activation energy (see graphs)

35. Enzymes Function – Enzymes speed up chemical reactions that take place
in cells
***Temperature, pH, and regulatory molecules can affect the activity of enzymes

36. Nature’s Catalysts
Enzymes are proteins that act as biological catalysts (speed up reactions by lowering activation energy)
*Enzymes very specific

37. The Enzyme-Substrate Complex
The reactants of enzyme-catalyzed reactions are known as substrates.

38. The Enzyme-Substrate Complex
Substrates bind to a site on the enzyme called the active site
The active site and the substrates compared to “lock and key”