Biological Molecules
Biology H
Polymers
-Most biological molecules are polymers
-Usually a result of condensation reactions—covalently link monomers by removing
water molecules—OH removed from 1; H removed from the other
-Process requires energy and catalysts or enzymes
-Are broken down by hydrolysis reactions—water is added; H to one, OH to the other
Carbohydrates
-Functions: fuel and structural materials
-Monosaccharides: building blocks; produced in photosynthesis; stores energy in
chemical bonds which is used in cellular respiration
-Glucose, fructose, galactose: C6H12O6
-Disaccharide: 2 monosaccharides bonded together by a glycosidic linkage
-Maltose, lactose, sucrose
Polysaccharides
-Polymers of a few hundred to thousands of monosaccharides
-Starch: storage of glucose in plants; alpha 1,4 linkage of glucose; stored in plastids in
plants
-Glycogen: storage of glucose in animals; large, branched molecules; stored in muscle
and liver cells
-Cellulose: linear, unbranched polymer of glucose connected with beta 1,4 linkage; has a
different 3-D shape than starch
-Cannot be digested by most animals but can be digested by microorganisms
-Chitin: polymer of amino sugar; forms the exoskeleton of arthropods and the cell walls
of fungi
Lipids
-Glycerol + 3 fatty acids
-Differ from one another by:
-Type of fatty acid (# of carbons, location and number of double bonds)
-Saturated vs unsaturated
-Functions: compact energy storage in C-H bonds, insulation, cushioning of organs
Proteins
-Tools of the cell
-Differ in:
-Order of amino acids
-3-D shape
-Proteins function is determined by its shape