Membrane biology

Observing Osmosis INTRODUCTION Osmosis is the “diffusion of water across a selectively permeable membrane” (Raven et al. G-16). In this experiment, dialysis tubing was used to mimic the selectively permeable membrane to show what osmosis does when placed in different solutes. We filled dialysis tubes fill with different percentages of solute and placed them in beakers full of a different solute. Through this experiment, I saw what happens when the solution becomes hypertonic, hypotonic, and…

Abstract This lab was conducted in order to determine the molarity of sucrose concentration where the mass of 2cm^3 of Classic Russet potato segments and pear segments does not change, representing an isotonic concentration. By calculating the change of mass of the potato segment and pear segments prior to being placed in the sucrose solution against the mass after being in the sucrose solution for 45 minutes. Our goal was to determine what type of osmotic concentration was created as compared…

dehydration when the bacteria stored in freezer. When the water in the freezer converted to ice, solutes accumulate in the residual free water and cause high concentration of solutes that can denature biomolecules in the cell. Ice can also rupture membranes, though this problem is more often associated with cells lacking walls, such as cultured animal cells. Glycerol provide better protection to the preserved bacteria which are exposed to room temperature for extended…

Docking: In molecular modeling field, docking is a method which assumes the desired orientation of one molecule to a second molecule when bound to each other, to form a stable complex. Knowledge of the orientations can be used to assume the strength of association or binding affinity between the two molecules. The associations between biologically relevant molecules such as proteins, nucleic acids, carbohydrates, and lipids play a key role in signal transduction. Thus, the relative alignment of…

Abstract Bacteriorhodopsin is located in the plasma membrane of Halobacterium halobium, where it acts as a proton-pump, transporting protons out of the cell. Since its discovery in 1979, much research has been done on Bacteriorhodopsin and there have been many advancements in our knowledge. Firstly, on its structure and function and secondly, on the conformational changes it undergoes during retinal isomerisation. Introduction Bacteriorhodopsin is a globular protein, (Henderson, 1975) which…

One’s body is made of 70% of water that in which is the main component of the cells within one’s bodies. Within these cells, there are particles that move inside and outside through a semi-permeable membrane. This process is called diffusion. In diffusion, particles move in motion at a random speed from a high concentration to an area of low concentration until all of the molecules are dispersed evenly. It is important to remember that involvement with diffusion depends on the concentration. The…

Ethanol disrupts membranes by a number of methods. In particular what you must remember is, the size and fluidity of the membrane has a lot to do with the outside and inside environment. This environment consists of how much water, salts etc are in the cell versus out of the cell. Adding ethanol disrupts much of this. 1. Ethanol is permeable to cell membranes. Because of the nature of ethanol as a chemical is it able to get into the cell very easily. This disrupts the balance of the…

potato was used to model a cell experiencing osmosis, like a cell, the potato will let really small particles inside of it but without manipulation the potato will not let larger things move through it. Cells use osmosis to move things through their membrane, unlike a potato cells will also let non-polar substances to move through it. This experiment could’ve been compromised by the integrity of the beakers, whether they were cleaned, how well they were cleaned, and if there was residue of some…

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 constant. This organelle surrounds the cell, providing a selectively permeable membrane to keep the concentration of substances constant (Campbell, Neil et al.…

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 cross the membrane without any use of…