For a cells metabolism to take place, an internal environment has to be maintained.
Abstract
For a cells metabolism to take place, an internal environment has to be maintained. Without this internal environment, a cell would cease to live. The plasma membrane surrounds a cell defining the point where the outside world is kept from the inside. This plasma membrane regulates the passage of materials such as molecules, ions, salts, and enzymes to and from the cell. Through years of cell research, biologists have been able to recognize that a cell membrane is not stagnant barrier of separation but is an interactive complex that plays just as important of a role of the cells procedures as the organelles themselves within the cell. Such an intricate role of cell membranes means that they have to be maintained properly. If this biological membrane were to be breached or denatured by external factors, the homeostasis and metabolism within the cell would cease to exist. To see if thermal energy does fracture a cell membrane, heat was applied to beat extractions in water to see if the red pigment betacyanin was released which exists within the beet. Results of the tests were just as expected. At higher applied temperatures the beet extractions released much more betacyanin because of their fractured membranes. At 100 º C Absorbance was greater than 2.0 on the photospectrometer. At lower temperatures ( x < 20 º C ) release of the pigment was minimal. Although the results show this low amount, usually a cell membrane that freezes will fracture because of the crystals puncturing the cell wall and cell membrane. After the first experiment was done, the second experiment started. Betacyanin was tested alone at various temperatures to see if the pigment would denature and deconstruct. This would tell us if the results of the first experiment were valid. If denaturing of betacyanin were to result, the absorbance in the photospectrometer would be a lower value. The absorbance results were at a slight decline for the rise in temperature and at 100 º C the absorbance value was at its lowest of .28 (A).
Introduction
The physical properties of cell membranes are primarily composed of phospholipids. A phospholipid is composed of two fatty acid chains linked to two of the three carbons of a glycerol molecule (Solomon et al., 2002). The non-polar portion of the phospholipid is the fatty acid chain. To be non-polar, in simplified molecular terms, means that you are a water fearing molecule. This indicates that the fatty acid chain would not be found facing the internal or external environment of the cell because of its lack of water attraction. The third carbon of the glycerol molecule within the phospholipid has negatively charged phosphate group attached to it (Solomon et al., 2002). This phosphate group in nature tends to be attracted toward water which signals that it would be found on phospholipids facing the internal and external environment because of its attraction toward liquid water. These two parts of the phospholipid, one “water loving” and one “water fearing” signals that this structures most stable arrangement is in bilayer form (Solomon et al., 2002). A bilayer structure means that the hydrophilic heads of the phospholipids are in contact with an aqueous environment while the hydrophobic tails are deep within the interior of the structure, separated from water molecules. Though phospholipids are the major component of biological membranes, other structures are equally important. Integral and peripheral proteins serve as a communication site for cell activity (Visco 2002). They are used for cell adhesions, integrin, ion channels, enzyme catalytic sites, cell recognition and receptor sites (Visco 2002). Another component is cholesterol. The function of these molecules makes the membrane less permeable to small molecules by filling up holes in the phospholipid bilayer. These holes are created when the tails of phospholipids becomes attracted and attached to each other (Visco 2002). The phospholipid membrane of cells can only exist at certain environmental conditions. If these conditions are altered by naturally occurring processes or manually by experimental procedures, the structure of the membrane can be dramatically altered thus destroying the cell (Ibrahim et al. 2001). Fluctuation of the environment can be related to differentiating pH levels, salt contents in aqueous settings, electromagnetic radiation, and thermal energy all of which can exist naturally or experimentally. Previous experiments done in our lab dealt with various pH levels but the focus of this new study is two determine the affects to these membranes with applied thermal energy. Heat stress is a major constraint of many plant species which affect many of the plants biological activities of the cell membrane (Ibrahim et al. 2001).
