Lipids

Functions of lipids

Long term energy storage, structure of cell membranes, protection

Are lipids polar or nonpolar?

Nonpolar

Carbon, hydrogen, and oxygen

Which elements do lipids have?

Fats, oils, waxes, phospholipids, steroids

Different examples of lipids

Globule

Clear oil droplet lipids form when stored in a cell (due to nonpolarity)

Fatty acids and glycerol

Parts of lipids that are monomers

Function of triglycerides

Long-term energy storage and insulations

Fats and oils

Types of triglycerides

Triglyceride

3 fatty acids attached to a glycerol molecule

Unsaturated fatty acids

One or more double bonds, usually liquid at room temperature

Saturated fatty acids

No double bonds, usually solid at room temperature

Phospholipids

One glycerol + two fatty acids + modified phosphate group

Fatty acids are…

Nonpolar and hydrophobic

Phosphate group is…

Polar and hydrophilic

Phospholipids combine to form a lipid bilayer; polar phosphate heads face water, while nonpolar fatty acid tails face inward, forming a hydrophobic core

Phospholipids when they go in water

Steroids

Four fused carbon rings

Function of steroids

Component of animal membranes, regulation of other molecules

Cholesterol, testosterone, estrogen

Examples of steroids

Precursor molecule

A starting material that is transformed into a more complex substance

Several other steroids

What is cholesterol a precursor for?

Function of cholesterol

Builds body’s cell membranes and manufactures fat-based hormones

Lipoproteins

Proteins that carry cholesterol in blood

Plaque

Too much cholesterol built up in arteries

High density lipoproteins (HDL)

‘Good’ cholesterol, straight to liver for disposal

Low density lipoproteins (LDL)

‘Bad’ cholesterol, can clog arteries

Waxes

Type of structural lipid, long chain of fatty acid + long chain of alcohol

Properties of waxes

Waterproof and resistant to degradation (being broken down into simpler forms)

Function of waxes

Forms protective layers in plants and animals

Earwax, plant cuticle, beeswax

Examples of waxes