Lipids - Chapter 17

What are lipids defined by?

Lipids are defined operationally by their properties, not by their composition and structure.

What type of molecules are lipids?

Lipids are hydrocarbon-like organic molecules.

What types of lipids are there?

Fatty acids (saturated and unsaturated), glycerides, nonglyceride lipids (sphingolipids, steroids, waxes), and complex lipids (phospholipids, glycolipids).

What are the three major functions of lipids in human biochemistry?

To store energy in cells, as components of membranes, and as chemical messengers.

What is the difference between animal fats and plant oils in terms of their state at room temperature?

Animal fats are generally solid and have a high proportion of long-chain saturated fatty acids, while plant oils are generally liquid and have a high proportion of long-chain unsaturated fatty acids.

What are triglycerides composed of?

Triglycerides are esters of glycerol and long-chain fatty acids.

What is the process of hydrogenation?

Hydrogenation is the process where double bonds in polyunsaturated triglycerides are reduced to single bonds.

What is saponification?

Saponification is the cleavage of ester bonds by NaOH to produce glycerin and sodium soaps.

What are sphingolipids?

Sphingolipids are not derived from glycerol, are amphipathic, and include sphingomyelins and glycosphingolipids.

How do lipoproteins function in the body?

Lipoproteins transport lipids in the bloodstream by having a hydrophobic interior compatible with lipids and a hydrophilic exterior compatible with water.