Final answer:
High-Density Lipoprotein (HDL) picks up cholesterol from the bloodstream and transports it to the liver to prevent atherosclerosis, playing a key role in reducing the risk of heart disease.
Step-by-step explanation:
The type of lipoprotein that picks up cholesterol from the bloodstream and takes it to the liver is High-Density Lipoprotein (HDL). HDL is responsible for transporting excess cholesterol away from the arteries and back to the liver for processing, which is why it's often referred to as 'good cholesterol'. The liver then uses this cholesterol to produce bile, or recycles it within the body.
HDL comprises about 33% proteins and 67% lipids, mainly phospholipids and cholesterol. The normal concentration of HDL in the blood plasma is 50-130 mg/100 ml. It is crucial for the prevention of atherosclerosis, a condition characterized by the hardening and narrowing of the arteries due to plaque buildup, as it helps to remove cholesterol from arterial walls and thus mitigates the risk of heart disease.