Semipermeable membrane

by their structure they both have a number of features in common but all so lots of differences. The eukaryotic cell has a membrane enclosed organelle called the nucleus. This is where the DNA in the cell can be found. However the prokaryotic cell does not have a nucleus. The DNA in a prokaryotic cell is found in an area of the cell call the nucleoid this has no membrane separating it from the rest of the…

The study of the brain began by mapping structures such as lobes, cortexes, and regions. As modern medicine continues to make advancements so does the understanding of complex processes which take place inside of the human body such as the firing of action potentials in neuronal cells in the brain. The research presented in the paper “High-Fidelity optical reporting of neuronal electrical activity with an ultrafast fluorescent voltage sensor” shows just how far brain mapping has come and how far…

Fluid Mosaic model of the cell membrane and describe the functions of the proteins that are embedded in the membrane. The Fluid Mosaic model of the cell membrane is a hypothesis that describes the phospholipid bilayer and it proteins. It states that the membrane is flexible - fluid - and has various proteins embedded in it - a mosaic. These structures are in constant motion. Proposed by Singer and NIcolson in 1972, they asserted that proteins are inserted in the membrane, with the hydrophobic…

lipoproteins, viral pathogens interact with the lipid composition of a membrane to gain entry into a cell. They can gain entry by interacting directly with the lipid component or with the other components usually glycosphingolipids and using them as a receptor.1 Other viruses require a specific lipid composition such as lipid rafts that are rich in cholesterol and take advantage of the clustering of receptors there.1 Attachment to the lipid membrane is advantageous to the virus as endocytosis…

can transport different substances such as water, oxygen and nutrients, without cells nothing living could exist such as us humans as we need our vital organs and the many systems that keep us alive. Dissolved substances must enter through the cell membrane and entre into or out of a cell. Diffusion is what allows this process. Particles diffuse from a high concentrated area to an…

(IV) Porous Ceramics The concept behind nearly inert, micro-porous bioceramics (type2) is the ingrowths of tissue into pores on the surface or throughout the implant. The increased interfacial area between the implant and the tissues result in an increased inertial resistance to movement of the device in the tissue. The interface is established by the living tissue in the pores. This method of attachment is often termed biological fixation. It is capable of withstanding more complex stress…

structure of cell membranes and are the major constituents (Whitney et al., 2014). They consist of two groups, a head and a tail group. The head contains a hydrophilic phosphate group (meaning “water loving”, attracted to water). 
The tail group is made up of two strings of hydrogen and carbon atoms, called fatty acid chains (Cooper, 2000). These chains are hydrophobic, meaning they do not like to interact with water molecules. Because of this, phospholipids of a cell membrane form a double…

specialized cilia that can manipulate food into the oral groove and create a food vacuole (Gray). Phagocytosis starts when segments of the plasma membrane invaginate to form cytoplasmic vesicles that are transported into the cell interior (Karp 303). The vesicle then pinches off inwardly from the plasma membrane (Karp 315). Microfilaments in the plasma membrane (such as actin) extend into the cytosol to help aid the process of phagocytosis (Reaven). The phagosome will then fuse with a lysosome…

Early studies on the lateral diffusion of rhodopsin in ROS membranes resulted in viewing this visual receptor as monomeric entity freely diffusing in a phospholipid bilayer (Calvert et al., 2001; Chabre et al., 2003; Liebman et al., 1982; Poo and Cone, 1974). However, it is important to stress that the movement of rhodopsin restricted to approximately two-dimensional environment of membranous phospholipid bilayer would rather reduce its dynamic freedom by orders of magnitude relative to soluble…

Diffusion is the process in which molecules blend together because of their kinetic energy (Hyperphysics, n.d.). It is a type of transport located in the cell membrane. Diffusion could also be described as the movement of molecules from areas of high concentration to areas of low concentration. The molecules do this because all molecules are constantly moving, so in enough time the molecules will spread evenly. According to figure 1, the cell will make the outside solution the same…