Basic Chemistry
Chemistry:
• Chemistry is the science of matter.
– Scientists study chemicals, their properties, and REACTIONS (rxn).
• BIOCHEMISTRY is the chemistry of living things.
Water:
• most chemical rxns occur only in water (universal solvent)
• 90% or more of cells is H2O
• essential to life• Solutions are made up of the
–Solute:–Solvent:
Elements• most simple substance of
matter
• cannot be broken down
• ex. Fe. O, Mg, Na
Valence Electrons:
• outermost electrons
• (carry negative charge)
• responsible for bonding
• goal: to have a full valence energy level
Boxes on the Periodic Table
• Each box on the PT contains the following information:–Atomic number =
–Atomic Mass =
–Atomic Symbol =
–# of protons =
–#of neutrons =
–# of electrons =
6
C12.001
Compound
• Chemically bonding of 2 or more elements formed by:
1. Ionic Bonds:
2. Covalent Bonds
3. Polar Bonds
4. Hydrogen Bonds
Ionic Bond:–transfer of valence e-
–Forms between a metal and a nonmetal
–Ex. KI Potassium Iodide
Covalent bond:–Forms between 2 nonmetals
–Ex. CO = Carbon Monoxide
–Equal Sharing of Valence electrons
Polar Bonds • between covalent and
ionic bonds
• unequal sharing of the valence electrons
• have slightly positive and slightly negative ends
• Ex. Water!!
Adhesion and Cohesion • Water is attracted to other water.
–This is called cohesion.
• Water can also be attracted to other materials. –This is called adhesion.
Surface Tension• the cohesion of water molecules
at the surface of a body of water
Capillary Action
• Capillary action however, is related to the adhesive properties of water.
• water molecules are attracted to the straw molecules.
Hydrogen Bonds :
–Weaker bonds than ionic and covalent
–Allow for large biological molecules•Ex. Proteins
•DNA
–Bonds water molecules together
Acid and Bases:
• Are ionized
• Can conduct electrical current
• Located throughout the body–Ex. Mouth, stomach
Acid :
Acids:
• Have extra H+ ions
• Have a sour taste
• Have a low pH (between 1 – 5)
Bases:
Bases:
• Have OH- ions
• Have a slippery feel
• Have a high pH (b/w 8-12)
pH Scale:
• Based on the # of H ion present
Buffers:• keep its pH constant • resist changes in pH when acids
or bases are added to them.
• In the body proteins act as a buffer, ex. Blood
Neutralization:
• Combing an Acids with a base
• results is neither an acid or a base.
• H+ form the acid and the OH- form the base combine to form water
• Ex. HCl + NaOH NaCl +H2O acid + base salt + water
Acid , Base Indicators:
• Phenolphthalein (base only)• pH paper (both)• Universal Indicator Solution
(Both)• Litmus paper (either)
–Red–Blue
Litmus paper:
pH paper:
Universal Indicator Solution:
Phenolphthalein:
Clear in the presence of an acid
Pink in a base
Inorganic chemistry:
• compound usually does not contain carbon or hydrogen
Organic Chemistry: • the compounds usually found in Living
or once living things
• contains carbon and hydrogen
• most common elements in living things are:
• C, H, O, N, P
• Carbon is often referred to as the element of LIFE
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