1. Chapter 2-Chemistry of Life
Chemistry is the branch of science that looks at what things are made of and the changes that take place within these substances

2. Matter: anything that has mass and occupies space.
Elements: basic chemical substances…(periodic table)
Atoms: the smallest complete particle of an element.

3. Atomic Structure
Nucleus: center of the atom; contains the protons/neutrons
Protons: have positive charge
Neutrons: no charge
Electrons: outside the nucleus and have negative charge

4. Stuff I learned in Chemistry…
Atomic number: the number of protons in the nucleus…the identifying number of an element(SS#)
Atomic weight/mass: the number of protons + neutrons(the mass of nucleus)

5. Atoms may gain, lose, or share electrons…
Atomic Bonding
Atoms may gain, lose, or share electrons…
When atoms gain or lose electrons, they become ions.
Lose electrons = + ion
Gain electrons = - ion

6. Ionic Bonding
Ionic bonds occur when ions with opposite charges are attracted to one another
Ex: Na(+) and Cl(-) become NaCl-common salt

7. When atoms share electrons, they are bonding covalently.
Covalent bonding
When atoms share electrons, they are bonding covalently.
Molecule: when 2 or more atoms bond. Ex. O2 or H20
Compound: when atoms of different elements join.Ex. H20

8. 1-Synthesis: A+B—› AB H2+O=H2O 2-Decomposition: AB—›A+B H2O—›H2+O
Chemical Reactions
1-Synthesis: A+B—› AB H2+O=H2O
2-Decomposition: AB—›A+B H2O—›H2+O
3-Exchange: AB+CD—›AD+CB
4-Reversible: A+B‹—›AB (requires a catalyst)

9. Acids and Bases
Some compounds release ions when they react with water. These are called electrolytes.
Acids: release Hydrogen ions(H+) HCl—H+ + Cl-
Bases: release Hydroxyl ions(OH-) NaOH—Na+ + OH-

10. pH Scale Goes from 0-14 7 is neutral Less than 7 is acidic
Greater than 7 is basic
pH of blood is 7.4 ( )
Stomach acid is around 2.0
Tums/MOM is around 10.0

11. In general….organic means to contain Carbon/Hydrogen
Organic vs. Inorganic
In general….organic means to contain Carbon/Hydrogen
Organic compounds: carbohydrates, lipids, proteins, and nucleic acids
Inorganic compounds: water, oxygen, carbon dioxide, salts

12. Oxygen: used by our cells to drive chemical reactions(Kreb’s cycle)
Inorganic compounds
Water: most abundant compound in living material. Most important solvent in body.
Oxygen: used by our cells to drive chemical reactions(Kreb’s cycle)

13. Carbon Dioxide(CO2): waste product from chemical reactions
Inorganic Salts: sources of ions;needed for contraction of muscles, conduction of nervous impulses. Ex. Na, Cl, K, Ca, Mg

14. Organic Compounds Carbohydrates: provide energy for cells.
monosaccharides: simple sugars Ex. Glucose and fructose
disaccharides: double sugars Ex. Sucrose and lactose
-polysaccharides: many sugars Ex. Plant starch, glycogen

15. Lipids: insoluble in water Ex. Fats, phospholipids,&steroids
All used to build cell parts, supply energy, and make hormones

16. Nucleic Acids: carry genetic info.
Proteins: made of amino acids -> used for structural materials and energy;
Ex. Hormones, enzymes, and Hemoglobin
Nucleic Acids: carry genetic info.
Ex. DNA and RNA