Which of the following statements about receptor-mediated endocytosis is true? Multiple Choice
A It is used to transport material out of the cell.
B It is not specific
C It involves clathrin-coated pits.
D It involves transport of material into the cell through pores in the cell membrane.
E It does not use any energy.
The Correct Answer and Explanation is :
The correct answer is:
C) It involves clathrin-coated pits.
Explanation:
Receptor-mediated endocytosis is a specific, energy-dependent process by which cells take in various substances from their environment. This process is essential for the uptake of nutrients, hormones, and other molecules that are required by the cell. Let’s break down the reasoning for why C is correct and why the other options are incorrect:
A) It is used to transport material out of the cell.
This is false because receptor-mediated endocytosis is involved in the import of substances into the cell, not the export. Exocytosis, not endocytosis, is the process used to transport materials out of the cell.
B) It is not specific.
This is incorrect. Receptor-mediated endocytosis is a highly specific process. It involves the binding of specific ligands (e.g., hormones, nutrients) to receptors on the cell surface, which then triggers the invagination of the membrane to internalize the material.
C) It involves clathrin-coated pits.
This is correct. In receptor-mediated endocytosis, clathrin-coated pits are a crucial part of the process. Clathrin is a protein that coats the membrane in the region where the vesicle will form. These coated pits help in the budding process, which leads to the formation of vesicles that are internalized into the cell. After internalization, the clathrin coat is typically removed.
D) It involves transport of material into the cell through pores in the cell membrane.
This is false. Receptor-mediated endocytosis does not involve the creation of pores in the membrane. Instead, it involves the membrane folding inward to form a vesicle around the substances that are being taken up.
E) It does not use any energy.
This is incorrect. Receptor-mediated endocytosis is an active process that requires energy in the form of ATP to drive the invagination of the membrane, the formation of the vesicle, and the internalization of the cargo.
In summary, receptor-mediated endocytosis is a highly specific, energy-dependent process that relies on clathrin-coated pits to internalize molecules into the cell.