$\text{Phosphatidate} = \text{Diacylglycerol} + \text{Phosphate}$

Question 1

Which of the following is the primary function of lung surfactant in the alveoli?

Accepted Answer

Decrease alveolar surface tension to prevent collapse

Question 2

Premature infants are at risk for neonatal respiratory distress syndrome (RDS) due to a deficiency in which major surfactant phospholipid?

Accepted Answer

Dipalmitoyl phosphatidylcholine (DPPC)

Question 3

The lecithin:sphingomyelin ratio is used to assess fetal lung maturity. Which of the following best describes the interpretation of this ratio?

Accepted Answer

A ratio of $2$ or higher indicates mature lungs

Question 4

Which of the following statements about the synthesis of phosphatidate is correct?

Accepted Answer

Phosphatidate is formed from diacylglycerol and phosphate

Question 5

Which molecule is used to activate head groups during phospholipid synthesis, forming CDP-choline and CDP-ethanolamine?

Accepted Answer

CTP

Question 6

Which phospholipids are synthesized by activating the head group with CDP, rather than activating diacylglycerol?

Accepted Answer

Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine

Question 7

Which of the following reactions is the largest consumer of S-adenosylmethionine (SAM) in the body?

Accepted Answer

PE to PC conversion via three methylations

Question 8

Ceramide is synthesized from serine and palmitoyl-CoA. Which vitamin is required for the initial step of this synthesis?

Accepted Answer

Vitamin B6 (PLP)

Question 9

Which of the following is a precursor for both sphingomyelin and glycosphingolipids?

Accepted Answer

Ceramide

Question 10

Which enzyme is responsible for adding a sugar to ceramide during cerebroside synthesis?

Accepted Answer

Glycosyltransferase

Question 11

Which sugar is added to the H antigen to form the A blood group antigen?

Accepted Answer

N-acetylgalactosamine (GalNAc)

Question 12

A patient with blood type B has which sugar added to the H antigen on their red blood cell membrane?

Accepted Answer

Galactose

Question 13

Which of the following best describes the structure of glycosphingolipids?

Accepted Answer

Ceramide backbone with carbohydrate head group

Question 14

Which of the following is true regarding the concentration of phosphatidylcholine and sphingomyelin in amniotic fluid during gestation?

Accepted Answer

Phosphatidylcholine concentration rises sharply in late pregnancy, while sphingomyelin remains relatively constant

Question 15

Which of the following is a real-life consequence of lacking lung surfactant in neonates?

Accepted Answer

Ten times the normal pressure is required to re-inflate collapsed alveoli

Question 16

Which of the following is the correct formula for phosphatidate?

Accepted Answer

$	ext{Phosphatidate} = 	ext{Diacylglycerol} + 	ext{Phosphate}$

Question 17

Which of the following is a key step in the synthesis of sphingomyelin?

Accepted Answer

Ceramide combines with phosphocholine from phosphatidylcholine

Question 18

Which of the following is true about the synthesis of gangliosides?

Accepted Answer

Gangliosides are formed by adding oligosaccharides to cerebrosides

Question 19

Which of the following best describes the role of CTP in phospholipid synthesis?

Accepted Answer

CTP activates head groups for phospholipid synthesis by forming CDP derivatives

Synthesis and Function of Lung Surfactant and Membrane Lipids

Study Guide - Practice Questions