Membrane

Special delivery of toxic cell-free heme causes vascular damage in Sickle Cell Disease Scientists describe a novel mechanism responsible for blood vessel injury in Sickle Cell Disease (SCD): microparticles derived from sickle cells deliver heme to the vascular endothelial cells causing oxidative damage. Sickle Cell Disease (SCD) is an inherited blood disorder caused by a single base mutation in the DNA of affected patients, producing abnormal hemoglobin molecules. In SCD, red blood cells…

a very complex and vital body system. The immune system involves both innate and adaptive immunity. Innate immunity functions as the “first responder” system of the body. The skin, the mucous membranes are the first line of defense in innate immunity. The skin and mucous membranes serve to prevent microbes from entering the body. If microbes enter the body, then the tears, saliva, urine flow, vaginal secretions, defecation, vomiting, and perspiration will try to expel them. If the…

Osmosis is the movement of a solvent, water, through the cellular membrane. Salt triggers osmosis by attracting water and causing it to travel across the membrane. When new salt is introduced in the substrate there is a higher amount of salt concentration on the outside of the cellular membrane. This is what is known as a hypertonic solution meaning there are more solutes on the outside of the cellular membrane. A requirement for plants to successfully germinate is the presence of water…

glucose enters the cell The glucose enters the cell through facilitated diffusion because it’s a large molecule and only small, and non-polar molecules can pass through the membrane via simple diffusion. Facilitated diffusion occurs with the help of carrier proteins, which shuttles the molecules across the cell’s membrane without using…

the folding stage. For instance, membrane proteins contain large amounts of lipids, which are hydrophobic, as water and fats such as oil do not mix. The folding of a protein…

Alkylated polycyclic aromatic compounds (alkyl-PACs) are the major aromatic constituent of total PAH in crude oil and originated from incomplete combustion process. Whereas benzo[a]pyrene (BaP) is a well-known human carcinogen, dibenzothiophene (DBT) and retene (Ret) are not; however, all three compounds are important environmental pollutants. Their toxicity is not yet characterized. In this study, we used BaP (parent PAH), DBT and Ret (alkyl-PACs) to elucidate the mechanism of neurotoxicity…

The Nisin Bacteriocin Introduction Nisin is a bacteriosin peptide made up of 34 amino acid residues that contain uncommon amino acids such as lanthionine and didehydroalanine. It is a substance produced by both gram positive and gram negative bacteria to control the growth of other bacteria species to reduce competition for substrate and space. Nisin has received attention from researchers making it the most exploited bacteriosin (Shetty, Pometto and Levin, 2006). The attention from…

Cell Biology Beta cells in pancreatic tissues are described as eukaryotic cells and not prokaryotic, this is because the cell is larger in size and there is a true nucleus present which contains DNA. In prokaryotic cell there isn’t a nucleus and the DNA is free within the cytoplasm. Also Beta cells have many organelles and there is mitochondria present, which in a prokaryotic cell there are fewer organelles and there aren’t any mitochondria present. Beta cells in the pancreatic tissue release…

inner ear) which is a band-pass filter and transducer of sound into neural impulses (Ketten 1994). Another important functional aspect of the middle ear is that the quantity of sound energy captured by the pinnae and tympanic membrane increases as the size of the membrane increases, so the ossicles in the middle ear endure the vibrations (Nummela 1995). They also use their ears in succession with the fatty pads of their feet to aid in the ability to hear sounds over long distances. The sounds…

skin and toxicity in the nervous system (Los et al. 2013). The toxin is secreted by S. aureus in a monomeric form that binds to the eukaryotic cell membranes. On target membranes, the subunits oligomerize to create heptameric rings with a central pore, leading to cell death (Berube and Wardenburg 2013). The central pore formed on the target membrane can now permit the exchange of simple ions, like Ca2+, that would result in apoptosis. (Berube and Wardenburg 2013). All of these factors can lead…