Chapter 24 Quiz

Question 1

Triacylglycerols are the major energy-storing lipids, whereas phosphoglycerols, sphingomyelin, and glycosphingolipids are amphipathic and have structural functions in cell membranes as well as other specialized roles.

Answer 1

True

Question 2

Triacylglycerols and some phosphoglycerols are synthesized

by progressive acylation of glycerol-3-phosphate.

Answer 2

True

Question 3

The pathway bifurcates at phosphatidate, forming inositol phospholipids and cardiolipin on the one hand and triacylglycerol and choline and ethanolamine phospholipids on the other.

Answer 3

True

Question 4

Plasmalogens and platelet-activating factor (PAF) are ether phospholipids formed from dihydroxyacetone phosphate.

Answer 4

True

Question 5

Sphingolipids are formed from ceramide (N-acylsphingosine). Sphingomyelin is present in membranes of organelles involved in secretory processes (eg, Golgi apparatus).

Answer 5

True

Question 6

The simplest glycosphingolipids are a combination of ceramide plus a sugar residue (eg, GalCer in myelin).

Answer 6

True

Question 7

Gangliosides are more complex glycosphingolipids containing more sugar residues plus
sialic acid.

Answer 7

True

Question 8

They are present in the outer layer of the plasma membrane, where they contribute to the glycocalyx and are important as antigens and cell receptors.

Answer 8

True

Question 9

Phospholipids and sphingolipids are involved in several disease processes, including infant respiratory distress syndrome (lack of lung surfactant), multiple sclerosis (demyelination), and sphingolipidoses (inability to break down sphingolipids in lysosomes due to inherited defects in hydrolase enzymes).

Answer 9

True