Natural Killer Cells Lymphocytes

Full Answer Section

     

• Golgi apparatus: The Golgi apparatus is responsible for packaging and sorting proteins. In NK cells, the Golgi apparatus is involved in the production and secretion of cytotoxic proteins.
• Endoplasmic reticulum (ER): The ER is responsible for the synthesis and folding of proteins. In NK cells, the ER is involved in the production of cytotoxic proteins.
• Ribosomes: Ribosomes are the organelles responsible for protein synthesis. NK cells produce a large amount of cytotoxic proteins, and they have a high number of ribosomes.
• Lysosomes: Lysosomes are organelles that contain enzymes that break down cellular waste products. In NK cells, lysosomes are involved in the destruction of target cells.
• Centrosome: The centrosome is the organelle that organizes the cell's cytoskeleton. The cytoskeleton is a network of fibers that provides structural support for the cell.
• Cell membrane: The cell membrane is the outermost layer of the cell. It separates the cell from the external environment.

Specialized organelles in NK cell structure:

• Cytotoxic granules: Cytotoxic granules are organelles that contain cytotoxic proteins. These proteins are released by NK cells to kill target cells.
• Lytic granules: Lytic granules are a type of cytotoxic granule that contain perforin and granzymes. Perforin forms pores in the target cell membrane, allowing granzymes to enter the cell. Granzymes then induce apoptosis (programmed cell death) in the target cell.
• Dense granules: Dense granules are a type of cytotoxic granule that contain granulysin. Granulysin is a protein that can damage the cell membrane of target cells.
• Natural cytotoxicity receptors (NCRs): NCRs are a family of receptors that are expressed on the surface of NK cells. NCRs recognize ligands on the surface of target cells, and they trigger the release of cytotoxic proteins from NK cells.
• Killer cell immunoglobulin-like receptors (KIRs): KIRs are a family of receptors that are expressed on the surface of NK cells. KIRs recognize MHC class I molecules on the surface of target cells. MHC class I molecules are expressed by all nucleated cells in the body. KIRs can either inhibit or activate NK cell cytotoxicity.

Conclusion NK cells are important components of the innate immune system. They play a critical role in the defense against viruses, tumors, and other pathogens. The organelles and specialized organelles in NK cells are essential for their ability to carry out their functions.  

Sample Answer

 

Organelles in natural killer (NK) cell structure:

• Nucleus: The nucleus is the control center of the cell, containing the genetic material (DNA). In NK cells, the nucleus is typically large and indented, with a prominent nucleolus.
• Cytoplasm: The cytoplasm is the gel-like substance that fills the cell between the nucleus and the cell membrane. In NK cells, the cytoplasm is rich in granules containing cytotoxic proteins.
• Mitochondria: Mitochondria are the organelles responsible for producing energy for the cell. NK cells are highly active cells, and they require a large amount of energy to carry out their functions.