The Atom Atom
The basic unit of matter Subatomic parts of the
atom Proton (positively
charged particle in nucleus)
Neutron (neutral particle in nucleus)
Electron (negatively charged particle found on valences outside the nucleus)
electron
neutron
proton
Element Element
A pure substance that is comprised of a single atom
Each element has its own atomic number equaling the number of protons it has
4 most common elements are C,H,O,N (96% of all living things)
http://www.privatehand.com/flash/elements.html
Isotopes Isotope
An element that has different numbers of neutrons
Carbon 12, Carbon 13, Carbon 14 Because they have the same number of
electrons, all isotopes of an element have the same chemical properties
Radioactive isotopes are isotopes that are unstable and breakdown over time
Chemical Compounds When two or more elements are combined
they form a compound Compounds are formed when elements
form bonds between them Ionic (electrons are transferred) NaCl Covalent (electrons are shared) H20 Van der Waals Forces (polarity)
Properties of Water Polarity
An uneven distribution of electrons causing positive and negative poles in one molecule
Water Cont’d Hydrogen bonding
Weak bonds that hold water molecules together Adhesion (attraction between molecules of
different substances) Cohesion (attraction between molecules of the
same substance) Allows for capillary action (water can defy gravity)
Props of H20 Cont’d Solutions and suspensions
Mixtures are 2 or more elements or compounds physically put together but do not chemically combine (salt and pepper)
Solution – mixture in which the all components are evenly distributed in the solution
Combination of solute (what is being dissolved) and solvent (what is doing the dissolving)
i.e. saline solution
More Water Acid, bases, and pH
Acid: compound that forms H+ ions in a solution. pH level 0-6
Base: compound that forms OH- ions in a solution. pH level 8-14
Buffers: weak acids or bases that react with strong acids and bases to prevent sudden changes in pH
Still More Water Properties Density (ice is less dense as a solid) High specific heat (takes a lot of energy to
raise or lower temperature of water 1C) Surface tension (due to cohesion) Transparency (allows light to penetrate to
aquatic plants)
Organic Chemistry Study of all compounds that contain bonds
between carbon atoms Macromolecules (giant molecules) make up
living things. Macromolecules are formed through
polymerization Monomers join together to make polymers Basic math (add parts to make a whole)
4 Organic Compounds Macromolecules or biomolecules found in
living things Carbohydrates (sugars) Lipids (fats and oils) Nucleic Acids (DNA and RNA) Proteins (chains of amino acids)
Carbohydrates Compounds of carbon, hydrogen, and
oxygen in 1:2:1 ratio Main source of energy for living things 3 types of sugars (saccharide)
Monosaccharide (simple sugar – glucose) Disaccharide (2 sugars – sucrose) Polysacchride (many sugars – glycogen and
starches)
Lipids Biomolecules that are generally not soluble
in water (don’t dissolve) Made mostly from carbon and hydrogen
atoms Fats, oils, and waxes Used to store energy and form parts on
biological membranes (lipid bi-layers) Saturated and unsaturated
Nucleic Acids Molecules containing C,H,O,N,P Polymer made up of monomers called nucleotides
5 carbon sugar A phosphate group Nitogenous base
Nucleic acids store and transmit hereditary or genetic information
Two types DNA (deoxyribonucleic acid) RNA (ribonucleic acid)
Proteins Biomolecule made from C,H,O,N Polymer made up of monomers called amino
acids Proteins have numerous responsibilities in living
things Enzymatic Regulate cell processes Structural Transport Immune
Chemical Reactions Process that changes one set of chemicals
into another set of chemicals Involve breaking the bonds in reactants and
the formation of new bonds in products
Reactants and Products Reactants go into a chemical reaction Products are formed by a chemical reaction Examples
CO2 + H2O H2CO3
H2CO3 CO2 + H2O Identify which are the reactants and products in
the above equations
Types of Reactions Energy Absorbing Reaction (Endergonic)
Products have more energy than reactants Energy is stored
Energy Releasing Reaction (Exergonic) Reactants have more energy than products Energy is given off
Activation Energy Energy need to start a reaction
Effect of Enzymes on Rxns A catalyst is a substance that speeds up
the rate of a chemical reaction Enzymes are biological catalysts Therefore…enzymes speed up chemical
reactions in cells