Proton exchange membrane fuel cell

Destiny Mckenzie Teresa Elam, Emily Meyers,Carlee Brogdon The Replication of Osmosis in Cells Introduction: The differences between osmosis and diffusion is slight, but osmosis is the movement of water molecules from high concentration to low concentration, when diffusion is necessarily the same concept albeit without water molecules.Osmosis and Diffusion occur to achieve equilibrium in the cell; to maintain the cell’s homeostasis.Within the experiment two types of solutions were present:…

conditions inside a cell, such as a normal pH, salinity, and ion concentration, to keep the cell healthy. There are several parts of the cell that play a role in homeostasis, but one of the more prominent ones is the phospholipid bilayer membrane. The cell membrane surrounds the cell, and therefore plays a large role in keeping the internal conditions of the cells constant. As mentioned earlier, the phospholipid bilayer cell membrane is crucial in keeping the internal conditions of the cell…

Introduction The human cell consists of three parts; the plasma membrane, the cytoplasm, and the nucleus. The plasma membrane is the outer boundary of the cell, it separates two major fluid compartments- the intracellular fluid and the extracellular fluid, and plays a key role in cell transport. Cell transport is the movement of materials across a selectively permeable membrane, and this process can occur in two ways; passive transport and active transport. Passive transport allows substances to…

Receptors are protein molecules that receive chemical signals in the form of ligands and induce responses at cellular level. They are localized at the cell surface, cytoplasm or the nucleus, depending on their amino acid sequences. In addition to using these three different localizations to categorize receptors, the types of action of receptors are also used as a mean of classification. The four main classifications of receptors are: 1. Ionotropic (or ligand-gated ion channel) receptors, 2.…

cytoplasm by the outer and inner mitochondrial membrane.The outer membrane is porous and freely traversed by ions and small, uncharged molecules through pore-forming membrane proteins (porins), such as the voltage-dependent anion channel VDAC [19]. Any larger molecules, especially proteins, have to be imported by special translocases. Because of its porosity, there is no membrane potential across the outer membrane. By contrast, the inner membrane is a tight diffusion barrier to all ions and…

A single cell cannot grow larger and larger indefinitely because on a cellular level and metabolic level, a cell requires essential provisions, cell-to-cell communication, and transport of molecules/nutrients. The outside of a cell grows slower than the inside of a cell. If a single cell were to continuously grow the outside layer of the cell would not be able to keep up. The larger a cell is, the more difficult it is to transport nutrients and oxygen from outside of the cell into the inside of…

produces. In order to fully understand how a muscle contracts, it is necessary to first understand the structure of muscle cells. Muscles cells are large cells that are surrounded by a special membrane called the sarcolemma and are filled with fluid called sarcoplasm. The sarcoplasm abounds with mitochondria for energy production and ribosomes for protein manufacturing. Muscle cells are also packed with many…

In, “Movement of Molecules in or Out of Cells” on page 159 to 163, it reads, “A student put a drop of blood on a microscope slide and then looked at the cells under a microscope. Initially the magnified red blood cells looked like little round balls, however after adding a few drops of sugar water to the drop of blood, the student noticed that the cells appeared to become smaller.” Now the question stands, why did the red blood cells appear smaller? There were three possible explanations…

Simple diffusion is a passive process involving the movement of smaller, nonpolar molecules moving across a membrane from a high concentration area to a low concentration area without any forces acting upon the substance. Facilitated diffusion is a passive diffusion process involving the transportation of large or polar molecules and ions across the cell membrane (which they cannot normally pass through) with the help of transport proteins. Because facilitated diffusion is a form of passive…

vesicle (v-SNARE) and a target membrane (t-SNARE) with the aid of NSF, SNAPs and other yet unknown proteins bring the v-SNARE in close proximity to the t-SNARE facilitating membrane fusion (Sollner et al., 1993). It is now widely accepted that SNAREs serve as the core machineries necessary for vesicle targeting and fusion but are regulated by proteins like Sec1/MUNC18, Rab Ypt GTPases and others that binds to them (Rothman, 1994, Bonifacino and…