Chemistry of Life Look at your neighbor… what are they made of? v=swd6C39jcHo

Cornell Notes 1.Title it Chemistry of Life Study Guide. 2.On the right side of the page write your notes. 3. On the left side write topic headings. 4. On the bottom section of each page you will take add a summary after re-reading the notes you wrote.

Elements Pure substances Have only ONE type of atom Composed of: –Protons (+) –Electrons (-) –Neutrons (0) Examples:

What 4 elements are most present in organisms?

Composition of Elements Protons and neutrons in the nucleus Electrons in shells outside the nucleus 1 st shell needs 2 electrons to be full Outer shells need 8 electrons to be full Bohr Model

APEMANAPEMAN Atomic Number = Protons = Electrons. Mass of Atom - Atomic Number = Neutron Number

Atomic Number How many protons does magnesium have? How many electrons does sodium have?

Atomic Mass What is the atomic mass of sodium? How many protons (and electrons) does sodium have? How many neutrons does sodium have?

Do you know how the elements make molecules?

Molecule or Compound? A molecule is formed when two or more atoms join together chemically. atoms A compound is a molecule that contains at least two different elements.elements All compounds are molecules but not all molecules are compounds. Molecule or Compound ?

Pictures of Compounds Water H 2 O Glucose C 6 H 12 O 6

Types of Chemical Bonds Ionic – atoms GAIN or LOSE electrons to become stable, forming charged ions that are attracted to each other. (Think of a pull like magnets.) Covalent – atoms SHARE electrons with each other to become stable (full outer shell). Remember when elements bond together they have new chemical and physical properties. Now lets see chemical bonds in action.

Ionic Bonds Na has 1 outer shell electron Must either lose 1 or gain 7 Cl has 7 outer shell electrons Must either lose 7 or gain 1

Covalent Bonds in Water Each hydrogen SHARES 1 electron with oxygen Oxygen SHARES an electron with each hydrogen Part of the time each H has 2 outer shell (e-)’s Part of the time O has 8 outer shell (e-)’s

Water is a Polar Molecule Larger oxygen “hogs” the electrons and takes on a partially (-) charge Hydrogen takes on a partially (+) charge The positive and negative poles create a hydrogen bond that sticks the molecules together like a magnet.

Hydrogen Bonding in Water (+) end of one water molecule is attracted to the (-) end of another water molecule Makes water molecules stick together = hydrogen bond.

Mixtures & Solutions A combination of 2 or more substances that are NOT chemically united Each substance retains its original properties Can also be called solutions. Solutions have 2 parts a solvent and solute.

Acid or Base? Many substances can be classified as Acidic or Basic. Less than (<) 7 is an acid (more H+) Greater than 7 (>) is a base (more OH-) At 7 is neutral (H 2 O)  Living things pH 7.2…Are living things acidic or basic?

Macromolecules Macromolecule means LARGE molecule Carbohydrates – sugars and starches C, H, O Lipids – fats and oils C, H, O Proteins – muscle and enzymes C, H, O, N Nucleic acids – DNA and RNA C, H, O, N, P  Why do you eat food?  For raw materials to build and energy!

Carbohydrates Made up of C,H,O Biological Function: source of energy Examples: sugar, rice, bread, potatoes Monomer: monosaccharide

Lipids Made of C,H,O Biological Function: Store energy Biological examples: wax, oil, butter. Monomer: 1 glycerol and 3 fatty acids

Proteins Made of C,H,O,N Biological function: Building and repairing cells, metabolism: speeds up or slows down chemical reactions Biological example: meat/muscle, hair, nails, enzymes Monomer: amino acid

Enzymes Proteins that speed up chemical reactions in the cell (catalysts). Catabolism - breaking molecules Anabolism – making molecules

Nucleic Acids Made of C,H,O,N,P Biological Function: Information called genes, determines physical appearance Biological Example: DNA, RNA, ATP Monomer: nucleotides

So how do molecules (chemistry) become life (biology)?

Who can tell me what you’re made of? Carbohydrates – sugars CHO Lipids – fats CHO Proteins – muscle, hair, and enzymes CHON Nucleic Acids – DNA, RNA, ATP CHONP These are organic compounds all contain carbon made by an organism.

Cornell Notes Now: A.Read the notes you wrote B.Add Topic Headings in the Left Margin C.Add a summary to the bottom of each page

Review Time!!! Fill in the Macromolecule Graphic Organizer (you may get help from your neighbor)

Dehydration Synthesis and Hydrolysis /dehydrat.htmlhttp://nhscience.lonestar.edu/biol/dehydrat /dehydrat.html Hippocampus.org Macromolecules overview and review