MCQsOnline - Online Collection of MCQs of Medical PG Entrance Exams.

MCQ stands for Multiple Choice Questions sometimes called as Objective type questions. Here we discuss the Old Question Papers, High Yield Points and Strategies with respect to the Indian Medical Post Graduate PG Entrance Exams like AIIMS,AIPG, JIPMER, CMC Vellore, PGI Chandigarh, UPSC, TNPSC, State PG Exams like Tamil Nadu PG (TN PG), Delhi PG, UPPG, Tamilnadu PG (TNPG), Karnataka PG, MAHE, COMED-K etc.

Target PG

PG Preparation

Related Portals

Search This Site

If you cannot locate what you want to find, please search using the box given below

Monday, December 15, 2008

Apoprotein A-I activates LCAT Apoprotein C-I activates Lipoprotein lipase


About Apoproteins the following are true except
a.       Apoprotein A-I activates LCAT
b.      Apoprotein C-I activates Lipoprotein lipase
c.       Apoprotein C-II inhibits Lipoprotein lipase
d.      Apoprotein C-III inhibits Lipoprotein lipase
Answer :
c.                   Apoprotein C-II inhibits Lipoprotein lipase
Reference :
Chaterjee 6th Edition Page 383
Quality :
Reader
QTDF :
Chaterjee
Discussion :
Liporproteins consists of a non polar core and a single surface layer of amphipathi phopsholipid and cholesterol molecules.
The protein moiety of a lipoprotein is known as an apolipoprotein or apoprotein, constituting nearly 70 % of some HDL and as little as 1 % of chylomicrons
Explanation
a.       Apoprotein A-I and A-II activates LCAT
b.      Apoprotein C-I activates Lipoprotein lipase
c.       Apoprotein C-II inhibits Lipoprotein lipase
d.      Apoprotein C-III inhibits Lipoprotein lipase
Comments
The chylomicrons are released by exocytosis from enterocytes into lacteals, lymphatic vessels originating in the villi of the small intestine, and are then secreted into the bloodstream, at the place where the lymphatic system falls into the blood stream, at the thoracic duct's connection with the left subclavian vein.
Tips
The following table has been adapted from Harper
Lipoprotein
Source
Diameter (nm)
Density (g/ml)
Composition
Main Lipid Components
Apolipoproteins
Protein (%)
Lipids(%)
Chylomicrons
Intestine
90-1000
<0.95
1-2
98-99
Tricacylglycerol
A-I, A-II, A-IV, B-48, C-I, C-II, C-III, E
Chylomicron remnant
Chylomicrons
45-150
<1.006
6-8
92-94
Tricacylglycerol, Phospholipids, Cholesterol
B-48, E
VLDL
Liver (intestine)
30-90
0.95 – 1.006
7-10
90-93
Tricacylglycerol
B-100, C-I, C-II, C-III
IDL
VLDL
25-35
1.006 – 1.019
11
89
Tricacylglycerol, Cholesterol
B-100, E
LDL
VLDL
20-25
1.019 – 1.063
21
79
Cholesterol
B-100
HDL
HDL1
Liver, Intestine, VLDL, Chylomicrons
20-25
1.019 – 1.063
32
68
Phospholipids, Cholesterol
A-I, A-II, A-IV, C-I, C-II, C-III, D, E
HDL2
10-20
1.063-1.125
33
67
HDL3
5-10
1.125-1.210
57
43
Preb HDL
<5
>1.210
A-I
Albumin/free faty acids
>1.281
99
1
Free fatty acids
HDL : High Density lipoproteins
IDL : Intermediate Density lipoproteins
LDL : Low Density lipoproteins
VLDL : Very Low Density lipoproteins

No comments:

Post a Comment