carbon is unique because: 1. it has four valence electrons in its outer orbital. 2. it can bond with...

Carbon is unique because:

1. It has four valence electrons in its outer orbital.

2. It can bond with other carbon atoms to form chains of great length.

CARBON

• Can have single, double, or triple bonds.

• Can make rings.

• Can make millions of different large structures.

http://www.dkimages.com/discover/previews/795/940887.JPG

Carbon Compounds

• Cells are made of large biomolecules which are built from smaller, simpler, repeating units.

Macromolecules:

• Very big molecules made of thousands of smaller molecules.

• Formed by polymerization.

• Each small molecule is a monomer.

• Monomers join to form polymer.

Four types of macromolecules in living things:

1. Carbohydrates

2. Lipids

3. Nucleic acids

4. Proteins

Carbohydrates

polysaccharide made of sugar monomers - monosaccharides. Contains C,H,O

Ex: glucose

Function:• Energy supply• Structure support• Cell recognition

Monomer of starch

• Plants store excess sugar as starch and cellulose.

Lipids• Macromolecules (polymer) made mostly

from C,H chains

• Ex: fats, steroids, waxes, phospholipids

• Monomer = glycerol, fatty acids

Function:

• store energy

• waterproof coverings, cell membrane

Ex: cell membrane, earwax.

glycerol (polar) bonds with fatty acid tails (nonpolar).

• At least one C=C bond, fatty acid is unsaturated.

• More than one C=C, polyunsaturated.

Ex: oils

• No C=C bonds, saturated.

Ex: animal fats, butter

• Cooking oils are polyunsaturated, broken down more easily.

• Solid fats like butter, animal fat are saturated, harder to break down.

Nucleic Acids

• Nucleic acids (DNA, RNA) are polymers made of monomers called nucleotides.

• 3 parts of nucleotide: sugar, phosphate group, nitrogenous base. Ex: ATP

C,H,O,N,P

Function:• store and transmit genetic information• Energy carriers (ATP)

Each nucleotide has 3 parts: nitrogen base, phosphate group, sugar

Here are 3 nucleotides joined together to make a polymer: DNA

• Two types of nucleic acids:

• Deoxyribonucleic acid - DNA• Contains sugar called deoxyribose

• Ribonucleic acid - RNA• Contains sugar called ribose

Proteins

• Polymer made of chains of amino acids = monomers• Ex: muscle, enzymes• Amino acid (monomer) ex: tryptophan• Composition: C,H,O,N

Function:• Structure, support, and transport (muscles, bone)• Communication (cell membrane)• Catalyst for chemical reactions (enzymes)

Amino Acid:

Each amino acid has 3 groups: amino, carboxyl, R

Four levels of organization

• 1st: sequence of amino acids

• 2nd: chain is twisted or folded.

• 3rd: chain itself is folded.

• 4th: several chains in one protein can be intertwined and held by H-bonds and Van der Waals forces.

MacromoleculesType Polymer Monomer Elements Function

carbohydrate

Chemical Reactions

• Chemical reaction = the process that changes one set of chemicals into another.

• Chemical rxn always involves:• breaking of bonds in reactants• making of new bonds in products.

CO2 + H2O ----------> H2CO3

Which side of the arrow are the reactants located? Which side are products located?

Energy in Reactions

• Energy is stored in the bonds that hold a compound together.

• Energy is released or absorbed whenever chemical bonds break or form.

2H2 + O2 ---------> 2H2O + ENERGY!!!

Hydrogen gas burns in oxygen and released lots of energy!

But Energy + 2H2O -------> 2H2 + O2

requires lots of energy to happen

• All living things need energy input to make chemical reactions in their bodies happen.

• Where does this energy come from?

Food!

The bonds that hold molecules together in food.

Activation Energy

• the energy needed to get a rxn (reaction) started.

• Even rxns that release energy often require energy to start them.

Ex: dynamite.

Energy Releasing Reaction

Energy Absorbing Reaction

Enzymes

• A Catalyst is something that speeds up the rate of a chemical rxn.

• Enzymes are proteins that act as catalysts to speed up chemical reactions in cells.

• Enzymes provide a site for rxn to happen called active site.

• Reactants are called substrates.

• Lock and key design. Enzymes are specific to particular substrates.

• Enzyme is the “matchmaker” for rxns.

• Enzymes are affected by temperature, pH.

• Enzymes regulate chemical pathways that make materials, release energy, and transfer information in cells.

Enzyme Animation

• http://www.kscience.co.uk/animations/anim_2.htm

Youtube Enzyme Basics, Enzymedicahttp://www.youtube.com/watch?v=AFbPHlhI13g

Catalase Floating Disk Assay

• Catalase is an enzyme found in almost all living cells. It breaks down hydrogen peroxide into water and oxygen.

• 2 H2O2 → 2 H2O + O2

• http://www.youtube.com/watch?v=ItreW0X0R50