Chapter 26 - Lipids

Steroids

Steroids

________ are a class of plant and animal lipids with a distinctive tetracyclic structure made of three six- membered rings and one five- membered ring.

Oral contraceptives

________ contain a synthetic progestin (for example, norethindrone), which prevents pregnancy.

Triglycerides

________ high in unsaturated fatty acids are liquids at room temperature and are referred to as oils.

Prostaglandins

________ are a class of exceptionally physiologically active chemicals with a 20- carbon structure similar to prostanoic acid.

Cholesterol

________ is an integral part of animal membranes, and it is the compound from which human sex hormones, adrenocorticoid hormones, bile acids, and vitamin D are biosynthesized.

Soaps

________ are fatty acid sodium or potassium salts.

fatty acids

In naturally occurring ________, carbon- carbon double bonds are virtually always present in the cis orientation.

Eicosanoids

________ are a large family of natural lipids with 20 carbons that are produced from fatty acids and include prostaglandins, leukotrienes, thromboxanes, and prostacyclins, all of which are common and significant physiologically active chemicals.

phospholipid

A(n) ________ is formed by esterifying the phosphoric acid portion with low- molecular- weight alcohol, most often ethanolamine, choline, serine, or inositol.

Linear alkylbenzenesulfonates

________ are the most prevalent and commonly used synthetic detergents.

Vitamin E

________ acts as an antioxidant in the body by trapping peroxy radicals.

Oils

________ are partially hydrogenated (H2 is limited in the presence of a metal catalyst) to minimize certain unsaturated fatty acids.

High density lipoproteins

________ (HDLs) carry cholesterol from cells to the liver, where it is broken down into bile acids and excreted in the stool.

strong interaction

Because of the ________ between carboxylates and these ions, natural soaps precipitate as water- insoluble salts with Mg (II), Ca (II), and Fe (III) ions in hard water.

Low density lipoproteins

________ (LDLs) carry cholesterol from its manufacturing site in the liver to tissues and cells where it is needed.

Lipids

________ are a heterogeneous family of substances classified according to their solubility qualities; they are insoluble in water but soluble in diethyl ether, acetone, and dichloromethane.

Vitamin D

________ is the term given to a group of structurally similar compounds that play an important role in calcium and phosphorus metabolism control.

membrane phospholipids

According to the fluid mosaic model, ________ form lipid bilayers with membrane proteins as both peripheral and integral proteins connected with the bilayer.

Triglycerides

________ high in saturated fatty acids are solids or semisolids at room temperature and are referred to as fats.

Prostaglandins

________ are produced in response to physiological cues from phospholipid- bound arachidonic acid and other 20- carbon fatty acids.

fatty acids

Almost all ________ have an odd number of carbon atoms, often between 12 and 20.

Phospholipids

________ are the primary constituents of biological membranes.

Vitamin E

________ is a series of similar- structured chemicals, the most active of which is a- tocopherol.

Fatty acids

________ are long- chain carboxylic acids generated from the breakdown of animal fats, vegetable oils, and biological membrane phospholipids.