Chapter 2 - BIO 213

• elements


  the simplest type of matter with unique chemical properties
• Atom


  individual units of an element; composed of subatomic particles
• Nuetron


  no electrical charge
• proton


  one positive charge
• electron


  one negative charge
• nucleus


  formed by protons and neutrons; most of the volume of an atom occupied by electrons
• Intramolecular Bonding


  bonding occurs when outermost electrons from two atoms are either shared or transferred
• Ionic Bonding


  atoms exchange electrons; electrons are transferred from one atom to another creating charged ions
• Covalent Bonding


  two or more atoms share electron pairs
• molecule


  two ore more atoms help together by bonds
• cation:


  A positively charged ion
• Anion


  A negatively charged ion
• Single Covalent Bond


  two atoms share one pair of electrons
• Double Covalent Bonding


  two atoms share 4 electrons
• Nonpolar Covalent


  electrons are shared equally between atoms
• Polar Covalent


  electrons are not shared equally between atoms
• Intermolecular Bonding


  forces between molecules; result from weak electrostatic attractions between oppositely charged parts or molecules, or between ions and molecules; weaker than forces producing chemical bonds
• Hydrogen Bonds


  - Weak attractions between the positively charged hydrogen of one polar molecule and the negatively charged O, N, or F of another molecule

  
  

  ex. form bonds between water molecules; hold base pairs together in DNA
• Solubility


  ability of one substance to dissolve in another
• Solute


  Substance being dissolved
• solvent


  a substance capable of dissolving another substance
• solution


  the dissolved combination of a solute and solvent
• electrolytes


  solutions made by the dissociate of cations and anions in water which can conduct electrical currents
• Acid


  a substance that releases hydrogen ions when dissolved in a solution
• Base


  substance that releases hydroxide ions (OH-) when dissolved in a solution
• Buffer (hydrogen sponge)


  a substance that resists change in pH by binding or releasing H+ ions

  
  

  either absorbs hydrogen if you have too much, but can release hydrogen if you have too little
• Neutral


  pH of 7/ equal hydrogen and hydroxie ions
• acidic


  a greater concentration of hydrogen ions
• Alkaline or Basic


  a greater concentration of hydroxide ions
• Physiologic pH


  7.4
• reactants


  substance that enters into a chemical reaction
• Products


  substances that result from the reaction
• Anabolic/Synthesis Reactions


  a reaction that builds a larger product from a smaller reactants; oRequires energy -> is stored in newly formed chemical bonds

  responsible for growth, maintenance, and repair
• Catabolic (Decomposition) Reaction


  a reaction that breaks a larger reactant into smaller productsoBonds are broken->release energy stored in chemical bonds
• Molecules of Life


  Carbohydrate, Lipids, Proteins, Nucleic Acids
• Monosaccharides


  individual sugar molecules
• Polysaccharides


  chains of monosaccharides that serve as energy storage
• Phospholipids


  make up cell membranes
• Triglycerides


  energy, storage, protection
• steroids


  found in cell membranes, form cholesterol, steroid hormones, and other molecules