Water is a vital part for the function of organisms, as it is involved in the “energetics” of molecular interactions and conformational adaption of macromolecules in animal and plant cells, due to its structure, flexibility and several unique properties (Rand, 2004).
In an organism’s cell, various types of water are present. They are known as bound, hydration, vicinal and bulk water. 95% of watery body fluid is composed of bulk water, since they function as “space filling medium”, which supports life and creates an aqueous medium for cellular reactions (Watterson, 1987) .
Water as a “space filling medium”, also aid to assemble molecules, hence they can “achieve a configuration of lower free energy” (Rand, 2004).
Water’s effect on the functions of biological molecules, is due to the properties of water; which results from its unique structure and the way this structure allows water to form hydrogen bonds. Water molecules consist of two hydrogen atom and an oxygen atom, joined by a covalent bond. As the oxygen atom is more electronegative than hydrogen atom, it draws the electrons involved in the covalent bond, towards itself. This result in uneven distribution of electrons throughout the molecule, causing polarity within the molecule as the area around the hydrogen is slightly positive and the area around the oxygen is slightly negative. However, these charges are equal, so water molecule has no overall charge (Brooker et al., 2007).
As water is a polar molecule, it is an excellent transport medium, since it can dissolve and interact with a wide range of “polar and charged molecules” (Gerstein & Levitt, 1998), such as, water in the interstitial fluid, dissolves oxygen and carbon dioxide in blood, to be transported around th...
... middle of paper ...
...in organic media. Glasgow: Springer.
Nelson, D.L., Cox, M.M. and Lehninger, A.L., 2008. Lehninger principles of biochemistry. 5th ed. New York: W.H. Freeman and Company.
Rand, R.P., 2004. Probing the role of water in protein conformation and function. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences, 359(1448), pp. 1277-1284.
Schwabe, J.W.R., 1997. The role of water in protein DNA interactions. Current opinion in structural biology, 7 (1), pp. 126-134.
Smith, A.M., Coupland, G., Dolan, L., Harberd, N., Jones, J., Martin, C., Sablowski, R. and Amey, A., 2010. Plant biology. New York: Garland Science; Taylor & Francis distributor.
Taiz, L. and Zeiger, E., 2010. Plant physiology. 5th ed. Sunderland: Sinauer Associates.
Watterson, J.G., 1987. A Role for Water in Cell Structure. Biochemical Journal, 248(2), pp. 615-617.
other hand when an animal cell is put in pure water it will burst due
The study of nucleic acids has now become a fruitful and dynamic scientific enterprise. Nucleic acids are of unique importance in biological systems. Genes are made up of deoxyribonucleic acid or DNA, and each gene is a linear segment, or polymer, of a long DNA molecule. A DNA polymer, or DNA oligonucleotide, contains a linear arrangement of subunits called nucleotides. There are four types of nucleotides. Each nucleotide has three components; a phosphate group, a sugar and a base that contains nitrogen within its structure. The sugar moiety in DNA oligonucleotides is always dexoyribose, and there are four alternative bases: adenine (A), thymine (T), guanine (G), and cytosine (C). The phosphate groups and the deoxyribose sugars form the backbone of each DNA stand. The bases are joined to the deoxyribose sugar and stick out to the side. Both oligomers, DNA and RNA, consist of 5’->3’ phosphodiester-linked nucleotide units that are composed of a 2’-deoxy-D-ribose (DNA) or D-ribose (RNA) in their furanose forms and a heteroaromatic nucleobase (A, T, G, and C; A, U, G, C), and the resulting oligonucleotide chain is composed of a polar, negatively charged sugar-phosphate backbone and an array of hydrophobic nucleobases. The amphiphilic nature of these polymers dictates the assembly and maintenance of secondary and tertiary structures the oligonucleotides can form. In the DNA duplex structure, genetic information is stored as a linear nucleotide code. This code can be accessed and replicated. RNA, or ribonucleic acid, is another structurally related essential biopolymer. RNA differs from DNA in having the sugar ribose in place of the deoxyribos...
The direction of osmosis depends on the relative concentration of the solutes on the two sides. In osmosis, water can travel in three different ways. If the molecules outside the cell are lower than the concentration in the cytosol, the solution is said to be hypotonic to the cytosol, in this process, water diffuses into the cell until equilibrium is established. If the molecules outside the cell are higher than the concentration in the cytosol, the solution is said to be hypertonic to the cytosol, in this process, water diffuses out of the cell until equilibrium exists. If the molecules outside and inside the cell are equal, the solution is said to be isotonic to the cytosol, in this process, water diffuses into and out of the cell at equal rates, causing no net movement of water. In osmosis the cell is selectively permeable, meaning that it only allows certain substances to be transferred into and out of the cell. In osmosis, the proteins only on the surface are called peripheral proteins, which form carbohydrate chains whose purpose is used like antennae for communication. Embedded in the peripheral proteins are integral
Membranes play an integral function in trapping and securing metabolic products within the borders of a cell within an aqueous environment. Without a selectively permeable border surrounding sites of anabolic function, potential useful products of this metabolism would simply diffuse away in the aqueous environment contained within and surrounding the cell. However, securing metabolites within the cell also comes with a price of not being able to acquire potentially useful compounds from the surrounding environment. Some very small gases and polar uncharged compounds are able to simply diffuse across this membrane, moving to the site of lower concentration on either side of the membrane. However, larger uncharged and charged polar molecules,
Schumann, Gail L., and Cleora J. D'Arcy. Hungry Planet: Stories of Plant Diseases. St. Paul: American Phytopathological Society, 2012. Print.
Lauffer, H. B., Williams, P., & Lauffer, D. (2012). Wisconsin Fast Plants® Program. Retrieved February 26, 2014, from http://www.fastplants.org
The Biological Importance of Water as a Solvent and as a Medium for Living Organisms
Cain, M. L., Urry, L. A., & Reece, J. B. (2010). Campbell Biology. Benjamin Cummings.
Diffusion and osmosis are necessary for the efficient transport of substances in and out of living cells. Diffusion is the most common and effective transportation process between cells and their surroundings, the movement of a substance along a concentration gradient from high to low, allowing essential nutrients and compounds to be transported without expending energy. Osmosis is a special kind of diffusion, specific to water. In order to observe diffusion and osmosis in real and artificial cells, a series of experiments was put together to observe how the surface area to volume ratio effects the rates of diffusion by using agar in different shapes with different ratios, next the rate of diffusion due to tonicity was observed using different solutions with different tonicities. And lastly live plant cells were submerged in different solutions with varying water potentials to observe how was potential effects the rate of osmosis and diffusion. It was concluded that the larger surface area to volume ratio, the faster rate of diffusion, the hypertonic solutions caused water to leave a cell and the hypotonic solutions allowed water to enter a cell, and that water potential will move from high to low in an attempt to maintain equilibrium.
Water has a great number of roles in living organisms, this is largely to do with the structure and covalent bonding in a single water molecule, and between water molecules. Around 75% of the earth is covered in water, and it is reffered to as the most important Biochemical. Its chemical symbol is: H2O In a water molecule there are two bonding pairs and two non-bonding pairs of electrons. These four pairs of electrons repel one another, forming a tetrahedral pattern.
The water molecule is a very small one but because of its unique properties it behaves like
Rath, A. a. (2009). "Detergent binding explains anomalous SDS-PAGE migration of membrane proteins". Proceedings of the National Academy of Sciences , 1760–1765.
Sigfusson, Thorsteinn I. "Pathways to Hydrogen as an Energy Carrier." Philosophical Transactions: Mathematical, Physical and Engineering Sciences 365.1853 (2007): 1025-42. Web.
Water facilitates the transportation system of the body. It is the medium by which all the other nutrients and other essential elements are distributed to every part of the body. Water also transports the waste from the body.