Loading....
Coupon Accepted Successfully!

Biochemistry

Open Flashcards

Lipid

Question
8 out of 63
 

Which one of the following acts as lung surfactant?



A Sphingomyelin
B Lysolecithin

C Dipalmitoyl lecithin
D Cephalin

E Phosphatidyl inositol

Ans. C Dipalmitoyl Lecithin

Phospholipids are compound lipids, they contain in addition to fatty acid and glycerol/or other alcohol eg. sphingosine, a phosphoric acid residue, Nitrogen containing base and other substituents.

a. Phosphatidic acid = glycero phosphoric acid + 2 fatty acid.

b. Ceramide = sphingosine + fatty acid.

Eg.

a. Phosphatidic acid and phosphatidylglycerol.

b. Phosphatidylcholine — Lecithin: - they are most abound phospholipids of cell membrane and represent a large proportion of the body store of choline

Lecithin = glycerol .acid + phosphoric acid + choline

Dipalmitoyl Lecithin is a very effective surface active agent and a major constituent of the surfactant preventing adherence, due to surface tension, of the inner surfaces of the lungs. Its absence in premature Leads to respiratory distress syndrome.

c. Phosphatidyl ethanolamine is cephalin

Cephalin = glycerol + fatty acid + phosphoric acid + Ethanolamine

d. Phosphatidylinositol contain no base but have inositol in its place. They are found in Brain, liver, heart and soybean. It is a precursor of second messengers.

e. Phosphatidylserine: contain the amino acids serine rather than choline.

f. Lysophospholipidseg. Lysolecithin contain only one acyl radicalsphosphoacylglycerols important in the metabolism and inter conversion of phospholipids.

g. Plasmalogens: constitute 10% phospholipid of Brain and muscles. Structurally resemble Lecithin but posses an ether link on Sn-1-carbon instead of Ester link. The alkyl radical is an unsaturated

h. alcohol. Give +ve reaction when tested for aldehydes with Schiff’s reagent.

i. Sphingomyelins: contain: -

j. =fatty acid + phosphoric acid + choline + sphingosine; deficiency of sphingomyelase

Niemann pick disease accumulation of sphingomyelins

Lipid Flashcard List

63 flashcards
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)