Nucleic Acids and Recommended Daily Intake 10/15/09

Nucleic Acids Large, complex organic molecules that store and transfer genetic information in the cell – Two major types: Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) – DNA contains information that determines characteristics of an organism and directs its cell activities – RNA stores and transfer information from DNA essential for manufacturing proteins.

Both RNA and DNA are polymers composed of monomers called nucleotides. A nucleotide is made up of three components: phosphate group, a five-carbon sugar and a ring- shaped nitrogenous base. phosphate group deoxyribose (sugar) nitrogen-containing base Spiral-shaped double helix

Contains at least one double bond Contains only single bonds Characteristics of a Lipid Nonpolar Do not dissolve in water Contain fatty acids bonded to glycerol Have a high number of C and H but few O atoms Saturated FatUnsaturated Fat

Structure of a Fatty Acid Nonpolar Hydrocarbon chain Carboxyl group Nonpolar Inside the cell Polar Outside the cell Functions of a Lipid Function of a Lipid Broken down as a source of energy Make up cell membranes Used to make hormones

Broken down as a source of energy Found primarily in fats (vegetable oil) Liquids at room temperature May lower cholesterol Mainly from animal sources such as meat and dairy Solid at room temperature Results in high blood cholesterol Polar phosphate head Nonpolar fatty acid tail Phospholipid Waxes Consists of one long fatty chain and an alcohol chain

Steroids Four fused carbon rings with functional groups Types of Lipids Used to form a protective coating (waterproof)