The lipid and protein percentage in Chylomicrons is respectively:
**Core Concept**
Chylomicrons are a type of lipoprotein primarily responsible for transporting dietary triglycerides from the intestines to the liver, adipose tissue, and muscles. They are composed of a core of triglycerides surrounded by a shell of phospholipids, free cholesterol, and proteins.
**Why the Correct Answer is Right**
Chylomicrons are unique among lipoproteins due to their high triglyceride content and low protein content. The apolipoprotein B-48 (apoB-48) is the primary protein component of chylomicrons, which serves as a structural component and a ligand for receptor-mediated endocytosis. The high triglyceride content of chylomicrons is due to the incorporation of dietary triglycerides during their formation in the intestinal enterocytes.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the lipid percentage in chylomicrons is actually much higher than the protein percentage, not lower.
* **Option B:** This option is incorrect because the lipid percentage in chylomicrons is typically around 85-90%, not 50%.
* **Option C:** This option is incorrect because the protein percentage in chylomicrons is actually around 5-7%, not 20%.
**Clinical Pearl / High-Yield Fact**
Chylomicrons are the least dense lipoproteins and are the primary lipoproteins to be affected by fasting. They are also the primary lipoproteins to be cleared from the circulation by the enzyme lipoprotein lipase.
**Correct Answer: B. 85-90% lipid, 5-7% protein.**