1. Chapter 2

3.  The smallest particle of an element that has the chemical properties of the element.

4.  Three subatomic particles:  Protons: + charge  Neutrons: no charge  Electrons: - charge; in constant movement around the Nucleus  # protons = # electrons, so the atom is neutral overall. Amazing Atoms Equal mass; Found in the Nucleus

5.  A pure substance that consists entirely of one type of atom.  Listed on the periodic table.  Ex: hydrogen (H)

6.  Contain same number of protons & electrons (so are the same element), but have a differing number of neutrons.  Ex: carbon-12 & carbon-14

7.  Two or more elements chemically combined together.  The chemical and physical properties of a compound are different than the properties of the individual elements from which it is formed. ▪ Ex: NaCl

8.  Two types:  Ionic: Electrons are transferred from one atom to another; creates ions ▪ Ions: charged atoms ▪ Ex: Na+, Cl-  Covalent: Electrons are shared (travel around both nuclei); creates molecules ▪ Molecules: smallest unit of a compound with covalent bonds ▪ Ex: H2O (2 atoms of H, 1 atom of O)

9. A Good Review

10.  Composed of two or more elements or compounds.  NOT chemically combined.  Solution: a mixture with components evenly distributed throughout  Two parts:  Solute: the part that is dissolved  Solvent: the part that is dissolving

11.  Acids: form H + ions in a solution  pH = 1-7  Bases: form OH - in a solution  pH = 7-14  Buffers: weak acids or bases that react with strong acids or bases to prevent sudden changes in pH  Help maintain homeostasis!

13.  Carbon has 4 electrons for bonding, so it can form strong covalent bonds with many other elements (like H, O, P, S, and N).  Carbon can form single, double and triple bonds with itself.  Organic = contains Carbon

14.  Monomers: smaller unit  Polymers: larger compound  Types of Macromolecules: carbohydrates, lipids, nucleic acids, proteins

15. Chemical CompositionExamplesFunction in Living Things -C, H, O- monosaccharides: simple sugars ( glucose, fructose, galactose) - polysaccharides: complex sugars (glycogen, starch) - Main source of energy. - Structural purposes in some cells (cellulose in plants).

16. Chemical CompositionExamplesFunction in Living Things -C, H, O - Glycerol + fatty acid -fats, oil, waxes -saturated: all single bonds (animal fats = bad!) -unsaturated: at least one double bond (vegetable fats = good!) -Stored energy. -Membranes & waterproof coverings. -Chemical messengers (steroids).

17. Chemical CompositionExamplesFunction in Living Things -C, H, O, N, P - sugar + phosphate group (P) + nitrogenous base (N) - polymers of nucleotides - DNA, RNA- Store & transmit genetic information.

18. Chemical CompositionExamplesFunction in Living Things -C, H, O, N, S - polymers of amino acids - enzymes- Control reactions (enzymes) & cell processes. - Transport materials in & out of cells. - Fight disease (antibodies).

20.  When one set of chemicals changes into another set of chemicals. CO 2 + H 2 O  H 2 CO 3  Chemical reactions always involve the breaking of bonds in the reactants and the formation of new bond in the products.

21. CO 2 + H 2 O  H 2 CO 3  Reactants: elements or compounds that enter into a reaction  Ex: CO 2 & H 2 O  Products: elements or compounds that are produced by a reaction  Ex: H 2 CO 3

22. 2 HCl + 2 Na -> 2 NaCl + H 2  Remember the 2 after H 2, means that there are 2 atoms of H in this molecule. (For H 2 O, there are 2 atoms of H and 1 atom of O.)  The 2 in front of 2 HCl, means that there is 2 of the entire molecule, so 2 atoms of H and 2 atoms of Cl.

23.  Reactions that release energy often occur spontaneously.  Reactions that absorb energy will not occur without a source of energy.  Activation Energy: the energy needed to get a reaction started

24.  Catalyst: a substance that speeds up the rate of a chemical reaction by lowering the activation energy.  Enzymes: proteins that act as catalysts in cells.  Substrates: the reactants of an enzyme- catalyzed reaction  Active site: spot on the enzyme where the substrate binds

25.  Temperature, pH and regulatory molecules can affect the activity of enzymes. Video

26.  Dehydration synthesis: two molecules bond together & H 2 O is made  Used to make polysaccharides, lipids & proteins  Hydrolysis: H 2 O is used to split two molecules