Semen by definition is the fluid ejaculated from a male, which includes the sperm cells as well as a number of other components. The Elements (ingredients) Of Semen. Very simply put, seminal fluid is a thick white secretion rich in sugars, mostly fructose to fuel the sperm cells on their journey to the egg. This secretion is what composes the bulk of semen by volume (50-80%). Although mostly comprised of water, proteins, and sugars.
The T-cell receptor, or TCR, is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.
B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow. B cells are involved in the humoral immune response, whereas T cells are involved in cell-mediated immune response.Both B cells and T cells carry receptor molecules that recognize specific targets.s with B cells, each type of T cell recognizes a different antigen. Killer T cells are activated when their T cell receptor (TCR) binds to this specific antigen in a complex with the MHC Class I receptor of another cell. Recognition of this MHC:antigen complex is aided by a co-receptor on the T cell, called CD8.