Proton exchange membrane fuel cell

integral membrane-spanning protein that moves the neurotransmitter dopamine out of the synapse back into cytosol terminating therefore the signal of the neurotransmitter. The dopamine reuptake via DAT is the primary mechanism from which dopamine is cleared from synapses. Its function requires the binding and cotransport of two Na+ ions and one Cl− ion with the dopamine substrate. The driving force for DAT-mediated dopamine reuptake is the ion concentration gradient generated by the plasma…

appreciated particularly in epithelial cells and when their formation is compromised; I aim to briefly explore the cause of Crohn’s disease to illustrate this. Furthermore, I will outline the key structural components of TJs which make them dynamic across different tissues using the blood-brain barrier as an example meanwhile discussing some ambiguities that require further research. TJs play vital roles in paracellular transport (movement of substances via gaps between cells) (Anderson, Van…

(Kövecses 91) the biological function of cell membranes through the underlying descriptive structural megametaphors CELL MEMBRANE IS A WALL and TRANSPORT PROTEINS ARE DOORS and the mappings between them, and by “hiding” (Kövecses 92) other aspects of this concept. Throughout this chapter, Peter Raven and George Johnson pair these main conceptual metaphors with visual portrayals of transport proteins that enable molecules to pass through the “wall” of the cell, in order to develop a stronger…

Why the system is important? The purpose of osmoregulation is to maintain a constant, optimal osmotic pressure within the body or cell. (Biology online, 2009). It allows the body to maintain a suitable concentration of solutes and of water in body fluids. Water is needed in the body for the reasons mentioned above such as providing trasport of substances, acting as a solvent and for use in evaporative cooling mechanisms. This means as humans we must maintain an optimum level of water in the…

INTRODUCTION A membrane of the cell is the defensive wall that protects, controls and regulate the amount of ions and water that enter and exit it. While some substances, such as, water, can enter and exit the cell through osmosis, others have to be transported more in some systematic ways, such as, packing or transporting different ions through protein molecule. (Flinders (2016)) Knowing the permeability of a cell membrane helps scientists on many circumstances. One of them is how much…

INVESTING DIFFUSION THROUGH LIVING MEMBRANES Introduction Cells are living membranes. They are the basic unit of life. They are very unique in that they have the capability of carrying out a large number of chemical reactions in the body, ability to respond to stimuli, capable of producing more of themselves, they have a genetic program and the means to use it, they acquire energy and utilize it, all in the process of the functioning of the human body, The life of a cell is also dependent on…

Within the skeletal muscle cells, there are many organelles. Each cell contains a plasma membrane called the sarcolemma, covering the outer surface of the cell (Ivy Rose). The sarcolemma protects the muscle cell and allows for its shape to be kept. From the sarcolemma, tunnel-like extensions called transverse tubules pass through the muscle fiber (Ivy Rose). These transverse tubules connect the sarcoplasmic reticulum with the sarcolemma (Graham and Parker 117). The sarcoplasmic reticulum is a…

Leukocidins are S.aureus toxins consist of two separate monomeric subunits which have the ability to bind to leukocyte membrane forming β barrel pores that extend through the phospholipid bilayer leading to lysis of leukocyte (fig. 1). There are six known leucocidins (lukED, lukSF, HlgAB, HlgCB, LukAB/HG and LukMFʹ). All S.aureus strains can produce three types of leukocidins at least (LukAB/HG, HlgAB, and HlgCB). Also, all leucocidins can infect human except LukMFʹ which can detected on…

Aquaporins are a family of membrane proteins that selectively conduct water molecules in and out of the cell, while at the same time preventing the passage of ions and other solutes. They can be found in animal, bacteria, and plant cells. So far 13 Aquaporins have been discovered (AQP0-AQP12) some of the Aquaporins only transport water molecules, such as AQP1, AQP2, AQP4, AQP5 and AQP8. Aquaporins that transport water and other solutes are called aquaglyceroporins, these can transport glycerol,…

all aerobic cells of higher animals and plants and also certain microorganism like protozoa. Studies show that that mitochondria are the direct descendants of a bacterial endosymbiont that became established at an early stage in a nucleus-containing host cell (Gray et al., 1999). Mitochondria are surrounded by a double-membrane system, consisting of inner and outer mitochondrial membranes separated by an intermembrane space. (Cooper, 2000). It has the outer membrane and the inner membrane. The…