Download Macromolecules 9-3

Macromolecules---Lipids and Proteins 9/3/2014
I.
II.
Yesterday we talked about dehydration synthesis and how removing one water
molecule joins monomers together to form polymers
a. This process can reverse
b. The adding of a water molecule to a polymer, which breaks the polymer into
a monomer is called hydrolysis
Lipids
a. DO NOT FORM POLYMERS
b. “Water-Fearing”
i. HYDROPHOBIC
c. Three classes of biologically important lipids
i. Fats
ii. Phospholipids
iii. Steroids
d. Fats
i. Composed of a glycerol
1. connects three fatty acids together
2.
ii. And Three fatty acids
1. Very long chains of C, H, and O
2. Contain the most energy in the molecule
iii. Fatty Acids vary in two ways
1. Number of Carbon Atoms
2. If they have any double bonds!
iv. Saturated Fats
1. Contains maximum Hydrogen atoms
2. NO DOUBLE BONDS
3. BAD TO CONSUME
4. Come from Animal fats
5. Solid at room temperature
v. Unsaturated Fats
1. At least one double
2. Plant/Fish sources
3. Liquid at room temperature
4. Considered best to consume
5. Two types of unsaturated fats
a. Monounsaturated
i. One double bond
b. Polyunsaturated
i. 2 or more bonds
e. Phospholipids
i. Remove one fatty acid chain from a regular fat
ii. Replace the fatty acid with a PHOSPHATE (PO4)
iii. Unique Property:
1. Fatty Acid “tails” are hydrophobic (Water-fearing)
2. Phosphate head is hydrophilic (water-loving)
iv. In the presence of water, a phospholipid will self assemble into a bilayer
v. The phospholipid forms the outer part that is contact with the water
1. The fatty acids form the inner part that is away from water
2.
3. This is the basic structure of all cellular membranes!
III.
Proteins
a. 50% of the dry mass of a cell!
i. Structure
ii. Support
iii. Storage
iv. Transport
v. Movement
vi. Cellular communication
b. Structure
i. Made of chains of amino acids
1. 20 different amino acids combining in infinite ways
2. 2.43 x 10 ^ 18 combinations! (20x19x18x17…1)
3. Sequence of the amino acid determines the shape of the
protein
4. The shape of the protein determines the function of the
protein!
c. Four Levels of Protein Structure
i. Primary
1. Sequence of amino acids in the protein
a. Determined by the structure of the DNA sequence
in the nucleus!
b. Every three letters in DNA codes for an amino acid
c. These amino acids form chains to make proteins
ii. Secondary
1. The folding and/or coiling of the protein chain
2. Caused by HYDROGEN bonds that occur between the amino
acids
3. Two types of secondary structure
a. Spiral shape (HELIX)
b. Folded Sheet (PLEATED)