Chapter 2 Chemistry of Life Section 1: Nature of Matter

Made of atoms Made of one atom

Atoms Matter: anything that has mass and takes up space Matter is made of atoms Atoms are made of electrons, protons, and neutrons A pure substance made of one specific kind of atom is called an element.

1.Mass number = protons and neutrons in the nucleus of an atom (added together) 2.Atomic number = number of protons or electrons (separately) 3.Symbol represents the element (made of one kind of atom) 4.Atomic mass = the weight of that element.

Chemical Bonding Matter Made of atoms Pure substances Elements Mixtures Homogenous and Heterogenous Compounds Made of 2 or more elements

1.Hydrogen bonding: weak chemical attraction between polar molecules. 2.Polar molecules are caused by unequal sharing of electrons 3.Covalent Bonding: share electrons equally to form a molecule

1.Ions: atoms with charges on them due to losing or gaining electrons 2.Ionic bonding usually between a metal and a nonmetal. The metal loses an electron to the nonmetal. The metal has a + charge, the nonmetal a – charge 3.Opposites attract

Section 2: Water and Solutions-Water in living things Properties of water: Cohesion Adhesion Capillary action

Aqueous Solutions

Section 3: Chemistry of Cells- Carbon compounds CarbohydratesLipidsProteinsNucleic Acids Characteristics Examples

Carbohydrates The 1:2:1 proportion Building blocks called monosaccharides Disaccharides like common table sugar sucrose Polysaccharides like starch in plants, and glycogen in animals store energy.

Lipids Non polar molecules Not soluble in water (hydrophobic) Phospholipids make up cell membranes called lipid bilayer Steroids and cholesterol: LDL and HDL Light absorbing pigments: chlorophyll Lots of energy in fats Saturated fats usually solid at room temperature Unsaturated fats oils/liquid at room temperature

Proteins Amino acids Some polar some nonpolar Fold into compact shapes Enzymes are proteins Collagen: connective tissue Hair, muscle proteins Hemoglobin

Nucleic Acids Nucleotides: sugar, base, and phosphate group DNA and RNA ATP

Section 4: Energy and Chemical reactions-Energy for Life processes

Energy in Chemical reactions