Chemistry of Life

Look at your neighbor… what are they made of?

https://www.youtube.com/watch?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

• 1st shell needs 2 electrons to be full

• Outer shells need 8 electrons to be full

Bohr Model

A P E

M A N

• 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.• A compound is a molecule that contains at

least two different elements. • All compounds are molecules but not all

molecules are compounds.Molecule

or Compoun

d?

Pictures of Compounds

WaterH2O

GlucoseC6H12O6

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 (H2O)

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, PWhy 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 NotesNow:

A.Read the notes you wroteB.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

• http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html

• Hippocampus.org Macromolecules overview and review