Q. Could you also let me know
1. HOW and WHERE they are removed from the bloodstream and
2. Dietary and lifestyle factors that may increase or decrease the amount in the blood (please explain).
I have been researching but I didn't find much.
A. Mostly the liver makes LDL and HDL which are fats/cholesterol..
You can stop eating cholesterol for the rest of your life and still have high levels. How can this be? For starters, all of your cells can create cholesterol. This is good because every cell in your body needs it to form protective membranes. Your body actually monitors your cells, and if it senses that a cell doesn't have enough cholesterol, it will produce more. Cholesterol also is an essential building block for naturally produced vitamin D and other good stuff, like estrogen and testosterone. But even though every cell can make its own cholesterol, some cells need extra help with their supply. This is where your liver comes in.
Your body, mainly your liver, produces 75 percent of your cholesterol; your small intestine also aids in both the creation and absorption of cholesterol [source: AHA]. The average diet adds another 300 to 500 mg of cholesterol [source: Schafer]. This external cholesterol comes from animal and dairy products. But even if you eat foods without cholesterol, the carbs, fats and proteins all break down eventually and release carbon, which your liver turns into cholesterol.
where is Low density lipoprotein (LDL) & High density lipoprotein (HDL) synthesized?
Q. Could you also let me know
1. HOW and WHERE they are removed from the bloodstream and
2. Dietary and lifestyle factors that may increase or decrease the amount in the blood (please explain).
I have been researching but I didn't find much.
A. HDL cholesterol "scavenges" your bad cholesterol and helps to eliminate LDL from the body. The only nonpharmacologic way to increase your HDL is to exercise.
Ingesting more soluble fiber lowers your LDL cholesterol because soluble fiber binds bile in the GI tract and it gets eliminated. Bile is synthesized using LDL, so that's why you sometimes see advertising on the side of quaker oats that they can lower your cholesterol. I believe the recommendation is to get 20-30 g of fiber / day.
why would chylomicron, low-density lipoprotein, and high-density lipoprotein form a spherical shape?
Q. not sure if this is important:
chylomicron has 4% phospholipid, 90% triacylglycerol, 5% cholesterol, 1% protein.
low-density lipoprotein has 20% phospholipid, 10% triacylglycerol, 45% cholesterol, 25% protein.
high-density lipoprotein has 30% phospholipid, 5% triacylglycerol, 20% cholesterol, 45% protein.
A. Particles (and systems in general) always follow the "principal of least energy" which reduces the free energy of a system to minimum.
Phospholipids are polar compounds based upon a glycerol backbone. Two fatty acids are attached to the phospholipid at the sn-1, and sn-2 position (end and middle respectively). Both fatty acids are non-polar and hydrophobic (water-hating). The third spot is taken by a polar group at the sn-3 position (e.g. the other end) which is hydrophilic (water loving). In addition to polar amino acids and proteins, the outer side of the lipoprotein particles face the water while the hydrophobic portions point inward, where triglycerides, cholesterol and cholesterol esters are.
The hydrophilic outer portion allows lipoprotein particles to stay suspended in serum and blood. The inner lipid and sterol portion attract each other and form a stable system.
The shape that reduces free energy to a minimum is a sphere so lipoprotein particles assume that shape.
Without the phospholipids and proteins surrounding the water-insoluble portions, the lipid and sterol molecules would simply coalesce, which would result in blobs of fat accumulating in the circulatory system.
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