Membrane

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.…

Tympanic Membrane Perforation A tympanic membrane perforation is a hole in your eardrum. The eardrum is a thin sheet of tissue that separates your middle ear from your ear canal. It protects your middle ear from germs that can cause infection. A tympanic membrane perforation can cause ear pain and hearing loss. CAUSES This condition may be caused by: An injury, such as: A blow to the side of the head. A fall onto water or a flat surface. Too much pressure on the eardrum,…

All things alive are made of cells. We humans have way too many to count. All the cells cluster and act together in the way so that we can function normally. Thanks to Agre and MacKinnon we now have more knowledge over molecular machines such ass channels, gates, and valves. The fact that water could go through the cell wall has always been a known thing, however, how the pores looked under function had been unknown. That is, until 1990 when Agre became the first to discover one. Chemical…

pressure through a semi-permeable membrane. To understand the purpose and the process of Reverse Osmosis, should understand the natural Osmosis operation. Natural Osmosis: The phenomenon of osmosis occurs when pure water flows from a dilute saline solution through a membrane into a higher concentrated saline solution. (Example of osmosis is our kidneys absorb water from our blood). Figure (A): Natural osmosis operation principle. (Zahid amjad) A semi-permeable membrane is placed between two…

In the fifth chapter of Biology, Peter Raven and George Johnson demonstrate the pedagogical functionality of metaphor by “highlighting” (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…

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 membranes are made up of phospholipids and proteins. The mitochondria has an outer membrane which is smooth and composed of equal amounts of phospholipids and proteins. It has a large number of special proteins known as the porins. The porins are integral membrane proteins and…

ways that it allows molecules and ions to cross its membrane, including bulk transport, osmosis, passive transport, and active transport. The purpose of the cell membrane is to protect the cell and only allow specific substances to cross the membrane, such as amino acids or water. Lipids hold the membrane together, along with proteins and carbohydrates. These lipids are saturated or unsaturated, and have a hydrophilic head. The tails hold the membrane together due to their fear of water.…

the fatty acid tails of the phospholipids). The none polar interior of the membrane creates a barrier which gives it the ability to be selective with what it allows in and out of the cell. The sugars attached to the proteins are very hydrophilic and so make the proteins a lot more polar than they would be without them. They are arranged into what is known as the fluid mosaic model, which allows them to float around the membrane and gives it fluidity, (if it wasn't for this fluidity, molecules…

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…

making proteins which produces energy by the devouring of glucose. The most interesting part of the cell, because of its complexity, would have to be the plasma membrane. Not only is it selectively permeable, but it protects the cell too. The membrane keeps the shape of the cell; some even consider it the skin of the cell. The plasma membrane does many things, but the main thing is it allows the diffusion of molecules.…