Cholesterol Flashcards
What is the first step in atherogenesis?
Endothelial injury caused by high LDL, smoking, hypertension, or diabetes.
What happens after lipid entry during atherogenesis?
LDL oxidizes within the vessel wall.
How do monocytes contribute to atherogenesis?
They migrate, become macrophages, and engulf oxidized LDL to form foam cells.
What is a fatty streak in atherogenesis?
Foam cell accumulation creating early lesions.
What is the role of smooth muscle cells in atherogenesis?
They migrate, proliferate, and form a fibrous cap.
What happens when a plaque ruptures in atherogenesis?
Exposes the lipid core, leading to thrombus formation and potential blockage.
What are triglycerides, and what is their function?
Energy storage molecules made of glycerol and three fatty acids.
How are triglycerides used during fasting?
Broken into free fatty acids and glycerol for energy.
What is cholesterol, and what are its functions?
A sterol used for cell membranes, hormones, bile acids, and vitamin D.
What is free cholesterol?
Active cholesterol in cell membranes and plasma, maintaining membrane fluidity.
What is esterified cholesterol?
Cholesterol combined with fatty acids for storage and transport.
What are the two sources of cholesterol?
Dietary (e.g., eggs, dairy) and liver synthesis (de novo).
What is the starting point of the mevalonate pathway?
Acetyl-CoA formation.
What enzyme converts HMG-CoA into mevalonate?
HMG-CoA reductase.
What is the target of statins in cholesterol synthesis?
HMG-CoA reductase.
What is squalene, and what is its role in cholesterol synthesis?
An intermediate processed into lanosterol and then cholesterol.