H: Transporting Cholesterol Around the Body Quiz

When HDL particles remove excess LDL particles, the body is working to maintain homeostasis. Is this an example of positive feedback or negative feedback?

• positive feedback

• negative feedback

What is the primary role of cholesterol in cell membranes?

• To act as a receptor for LDL particles.

• To maintain membrane fluidity.

• To produce steroid hormones.

• To transport fatty acids.

How does High-Density Lipoprotein (HDL) differ from Low-Density Lipoprotein (LDL) in terms of function?

• HDL transports cholesterol to cells, while LDL removes excess cholesterol.

• HDL removes excess cholesterol from the body, while LDL transports cholesterol to cells.

• HDL is insoluble in water, while LDL is soluble.

• HDL forms plaques in arteries, while LDL prevents them.

The LDL particle must bind to the __________to enter the cell.

• signal

• protein

• HDL

• LDLR

What process describes how an LDL particle enters a cell after binding to specific receptors on the cell membrane?

• Osmosis

• Diffusion

• Receptor-mediated endocytosis

• Active transport

What happens if there is an excessive accumulation of LDL in the blood?

• Cells produce more LDL receptors.

• HDL levels decrease significantly.

• Plaques may form on arterial walls, leading to atherosclerosis.

• Cholesterol is immediately used by cells.