Question

Explain endocytosis in cells

Answer 1

Explanation:

Function of Endocytosis

Endocytosis is used for receptor signaling, nutrient uptake, membrane remodeling, pathogen entry, and neurotransmission, as well as modulating cell signaling responses. In developing tissues, it has been found that endocytosis aids in cell migration. Toxins, pathogens, and foreign debris have also been found to exploit the different endocytic pathways in order to gain entry into the cell. The particles will recruit clathrins (proteins necessary for vesicle shape and formation) or will initiate the first steps of the pathway in order to begin the process to enter the cell.

Example of Endocytosis

Cholesterol is a much needed component in the cell that is present in the plasma membrane and is also used as a hormone precursor. A lipoprotein complex (such as LDL or low density lipoprotein) is then used to transport the cholesterol to other cells in the body. On the surface of the cell is a LDL receptor that binds the LDL complex to begin the endocytic process. These receptors were synthesized in the Endoplasmic Reticulum (ER) and were then transported and processed in the Golgi. Once the receptor is bound to the complex on the surface of the cell, clathrins are recruited along with other proteins that aid in the process. The receptors cluster together to form clathrin-coated pits. The coated pits are pinched off, forming endocytic vesicles, and are then uncoated. After uncoating, the vesicle is delivered to an endosome. The low pH in the endosome causes a conformational change that releases the LDL particles. These particles are then directed to the lysosome for degradation, releasing the cholesterol into the cell.

Answer 2

$\huge{\boxed{\mathcal{ENDOCYTOSIS}}}$

• Endocytosis is a process by which a cell takes in materials.

• They do so by invaginating some portions of cell membrane.

• Materials are taken inside the cell in the form of spherical structure called vesicles.

TYPES OF ENDOCYTOSIS :

1. Pinocytosis

In this type, fluid substances like fats, insulin, proteins, etc, are taken in.

2. Phagocytosis

In this type, the particles which are of large size are taken in.