Lipids Flashcards

Flashcards on Lipids

Lipids

Diverse group of organic molecules including fats, oils, waxes, steroids, and phospholipids.

Lipids

Characterized by lots of carbon and hydrogen but very few oxygen atoms.

Hydrophobic

Water fearing, do not have many OH bonds, are non-polar, and cannot form hydrogen bonds with water.

Functions of Lipids

High density energy storage, absorption of fat-soluble nutrients, padding, insulation, hormones, membranes, protection, structure, and waterproofing.

Waxes

Sticky rather than oily, solid at room temperature due to high melting point, prevents water loss in plants and guards our eardrums.

Steroids

Made up of a 4-carbon ring structure which different functional groups attached.

Cholesterol

Found in the plasma membrane and is a precursor for other steroids. Too much can lead to serious health effects.

Phospholipids

Lipids with a phosphate group that are the main component of cellular membranes.

Amphipathic

Has both hydrophilic and hydrophobic components.

Phospholipid

Can form a ring called a micelle. Important for certain cellular organelles like liposomes. This is how soap works to clean grease and food off plates.

Fat

Long term energy storage in animals, within adipocytes (fat cells) of adipose tissue. Insulates and protects.

Oils

Used by plants as energy storage. Stored within elaioplasts.

Fats and Oils

Consist of one glycerol (3-carbon, 3 hydroxyl groups) and three fatty acids (carboxyl functional group which can release H+).

Triglycerides

Building the triglyceride molecule took 3 dehydration synthesis reactions; breaking it down requires 3 hydrolysis reactions.

Fatty Acids

Mostly hydrophobic, acids release H+ ions.

Fatty Acids

Classified as saturated or unsaturated depending on the absence or presence of C=C bonds.

Saturated Fats

No C=C bonds.

Unsaturated Fats

Have C=C bonds.

Monounsaturated

If an unsaturated fatty acid has only one double bond in the hydrocarbon chain, it is called __.

Polyunsaturated

If an unsaturated fatty acid has more than one double bond in the hydrocarbon chain, it is called __.

Saturated Fats

More solid.

Unsaturated Fats

More liquid.

Hydrogenation

Oils converted to solids by adding hydrogen gas, breaking the double bonds between carbons.

Trans Fats

Carbon backbone cannot rotate around C=C, hydrogens are on different sides.

Trans Fats

Used to make fast food, snack food, fried food, and baked goods. Increases shelf life, decreases spoiling of food, can be heated to a high temperature repeatedly. More harmful than naturally occurring oils.