LipidsObjective:

B2 - Compare the structures & functions of carbohydrates, lipids, proteins, & nucleic acids & their organization into long complex molecules

Consist of: Mostly Carbon & Hydrogen with some Oxygen

Hate water (hydrophobic) Insoluble (won’t dissolve) in water

Function: Energy storage

Characteristics:

Examples of Lipids

Fats (helps conserve heat)

Oils Waxes (waterproof covering)

Butter Phospholipids (part of cell membrane)

Steroids (cholesterol, estrogen, testosterone)

Building Blocks of Lipids Glycerol Fatty acids

(monomers)

Fats (triglyceride) Always have 3 fatty acids There are 2 different kinds:

Saturated (no double bonds between the carbon atoms) - Solid at room temperature - Examples: butter

Unsaturated (have a double bond between two carbon atoms) - Liquid at room temperature - Examples: oil Polyunsaturated (have more than one double bond)

Phospholipids Like fats, but only have 2 fatty acids (this causes the glycerol, which now includes a phosphate group to like water, but the tails still hate water) Has a hydrophilic end and a hydrophobic end

Phospholipid Structure

Because it has a “split personality,” this forces this lipid to assume an interesting structure when in the presence of water. The hydrophilic (phosphate head side) surrounds the hydrophilic (fatty acid tails) shielding the tails from exposure to water

This makes up the phospholipid bilayer (cell membrane) of all cells

Etymology Lipids: (Gk. LIPOS, fat) Hydrophilic: hydro- (water) + -philic or -phile (Gk. PHILOS, loving) Hydrophobic: hydro- (water) + -phobic (Gk. PHOBOS, fear)

Practice:

Glycerol

Fatty acids

What is the function of lipids?

Energy storage

Which side of this molecule likes water?

Polar head group

This phospholipid bilayer is also called what?

Cell membrane