pore in Biological Definition

Ion channel

... and controlling the flow of ions , these pore -forming proteins help establish the small ... proteins closely packed around a water-filled pore through the plane of the membrane or lipid ... or less indiscriminately, the archetypal channel pore is just one or two atoms wide at its narrowest ...

Transmembrane receptor

... acetylcholine receptor , the transmembrane domain forms a protein-lined pore through the membrane, or ion channel . Upon activation of an extracellular domain by binding of the appropriate ligand, the pore becomes accessible to ions, which then pass through. In other receptors, ...

Apoptosis

... still appears complete; however, as observed by Kihlmark and colleagues, specialized caspases have already advanced in the degradation of nuclear pore proteins and have begun to degrade the lamin that underlies the nuclear envelope. It must be noted, also, that while the previous stage of initial ...

Cell nucleus

... with the lumen of the RER. Drawing of nucleus and the endoplasmic reticulum . (1) Nuclear envelope . (2) Ribosomes . (3) Nuclear pore complexes. (4) Nucleolus . (5) Chromatin . (6) Nucleus. (7) Endoplasmic reticulum. (8) Nucleoplasm . The whole structure is surrounded by ...

Cytotoxic T cell

... cell, making it expand and eventually lyse . T C also release granzyme , a serine protease , that can enter target cells via the perforin-formed pore and induce apoptosis (cell death). Most T C cells have present on the cell surface the protein CD8 , which is attracted to portions of the Class ...

Flagellum

... respective positions. The filament grows at its tip rather than at the base. The basal body has many traits in common with some types of secretory pore which have a hollow rod-like "plug" in their centers extending out through the plasma membrane, and it is thought that bacterial flagella may have ...

Leaf

... than in those of dicots . The epidermis is covered with pores called stomata (sing., stoma ), part of a stoma complex consisting of a pore surrounded on each side by chloroplast-containing guard cells , and two to four subsidiary cells that lack chloroplasts. The stoma complex ...

Skin

... facial skin care is of importance, and cosmetics are made to deal with the appearance of the person's face and condition of the skin, such as pore control and blackhead cleansing. Contents showTocToggle("show","hide") 1 Layers 2 Types 3 Functions 4 Aging and ...

Stoma

... In botany , a stoma (also stomate ; plural stomata ) is a tiny opening or pore , found mostly on the undersurface of a plant leaf , and used for gas exchange. Air containing carbon dioxide and oxygen enters the plant ...