Wednesday, September 22, 2010



Atoms and molecules

Today we received our unit one biology tests back. Class average of 75% woohoo!
(see Andrews during your lunch period to see tests)

Homework: read Chapters 2, 3, and 5 in the textbook for Thursday.
Mini assignment in "Cells R Us" packet (pg. 3) due Tuesday.
Are tanning beds a skin cancer risk?We began our Cell Unit notes, pages 1-4

I. Carbon
Carbon is an abundant atom. It can bond to 4 other atoms.
a. commonly bonds with hydrogen, nitrogen, and oxygen.
1.A drawn line in a molecule model resembles a bond.

carbon skeletons - chain of carbon atoms.
hydrocarbons - simplest organic compound.

2. Hydrocarbons can take up many different structures
i. ringed, double bonded, single bonded, branched, unbranched.

<---Carbon skeletons can vary in length.

II. Functional groups

Functional groups allow molecules to bond. A molecule can have one or more functional groups attached.
The types of functional groups:

  • Hydroxyl group - found in alcohols and sugars
  • Carbonyl group - found in sugars (carbon)
  • Amino group - found in amino acids (nitrogen)
  • Carboxyl group - molecules with carboxyl groups are called carboxylic acids; found in amino acids, fatty acids, some vitamins. Combination of alcohol and carbon.
NOTICE: Carbonyl and CarBOXyl are two different groups.

III. Building larger molecules
Macromolecules - biological molecules like DNA, proteins, and carbohydrates. A.K.A: big molecule.
Monomer - chemical subunit. Building block for polymers, macromolecules consisting of many identical/similar monomers bonded together.
a. How do I remember this? MONOmer, a SINGLE chemical subunit that makes up a POLYmer, many monomers bonded.
b. 4 major macromolecules:
1. Proteins
2. Carbohydrates
3. Nucleic acids
4. Lipids
Dehydration - linking of monomers together to form a polymer. WATER IS REMOVED BY TAKING A HYDROGEN (H) FROM ONE MOLECULE AND AN ALCOHOL (OH) FROM THE OTHER.
bonds cannot be left open.
a. If you take H (hydrogen) from one molecule and OH (alcohol) from another molecule, the bonds are open causing them to join together.
1. from those open bonds comes water, H2O (H+HO)
b. Hydrolysis - to break with water.
1. this is the opposite of dehydration. The polymer breaks into monomers because you are breaking the bonds of the polymer by ADDING a water molecule.

To make a bond, you must lose water.

Matter gets changed, not eliminated or added. That is why you must add the bond along with the monosaccharides

V. Carbohydrates

All monosaccharides
are C6H12O6

a. They are simple sugars. Glucose and fructose.

DisaccharidesFormed by synthesis of two monosaccharides.
a. broken down by hydrolysis into two monosaccharides.

Starch - storage polysaccharide.
Glycogen - stores excess sugar, found in animals (it is branched. Remember what branched is? It's another structure of carbon skeletons.)
Cellulose - most abundant organic compound;; found in plants.
CANNOT be hydrolyzed. (what does hydrolyzed mean? Cannot be broken up by water. AKA Fiber).
Almost all carbohydrates are hydrophilic. (love water!)

Next scribe: Skyler S.

No comments:

Post a Comment