Chapter 2 bio notes.docx - Chapter 2 I Macromolecules A...

Chapter 2
I. Macromolecules
A. Macromolecules of life
 Polysaccharides
 Lipids
 Proteins
 Nucleic Acids
Notes - most macromolecules are polymers
-Polymers are smaller molecules linked together, cells link monomers by dehydration reactions
-cells break up polymers into monomers by hydrolysis reactions
Carbohydrates (CH2O)

Monosaccharides to polysaccharides

Sugars for energy and structure

Simple sugars
o
Monosaccharides: glucose and fructose
o
Disaccharides: sucrose and lactose
A. Polysaccharides
•Starch: digestible to produce monosaccharides for energy
–Plant energy storage
–Potatoes and grains
•Glycogen : digestible to produce monosaccharides for energy
–Animal energy storage
–Liver, muscle
Glycogen: highly branched
 Hydrolyzed to release glucose when needed
•Cellulose: not digestible by animals
–most abundant organic molecule on Earth
–Cable-like fibrils in plant walls
–Major component of wood
Dietary fiber
-structural compound
-Parallel cellulose are joined together by hydrogen bonds forming part of a fibril
- cannot be hydrolyzed by animals
B. Lipids
 Lipids are HYDROPHOBIC
 Groups of lipids
o Fats and oils
a. Energy storage
b. Cushioning
c. insulation
 Phospholipids
a. Cell membranes
 Steroids
a. Sex and stress hormones
Fats and Oils
Saturated vs Unsaturated fatty acids
 Refer to the structure of the carbon chains of the fatty acids

Hydrogenation-enables a fat to be more solid at room temp which is better for baking/processed
foods
Saturated- maximum number of hydrogens bonded to carbons
 Most animal fats
 Saturated and trans fat contribute to cardiovascular
Unsaturated- fewer than maximum number of hydrogens bonded to carbons
 Most plant fats
 One or more double bonds
 Monounsaturated
 Polyunsaturated
Triglycerides- glycerol + 3 fatty acids
Phospholipid- glycerol + 2 fatty acids + phosphate group
 Hydrophilic head and hydrophobic tails
Steroids
 Cholesterol: “base steroid” to form other steroids
 Anabolic steroids build muscle quickly
 Synthetic anabolic steroids: variants of testosterone
C. Proteins
 Polymer of amino acid monomers
 Polypeptides
o Amino acids link together by dehydration reactions

o Arrangement of amino acids makes each one different
LEVELS OF PROTEIN STRUCTURES
Primary structure : sequence of amino acids. Precise primary structure of a protein is not