Water Properties: Polarity

Water Properties: Polarity CHRISTABEL SAMPA Discuss the assertion that water has several unique properties that make it vital not only for human beings, but for all living organisms to survive. Introduction Water is a normal oxide made of two hydrogen atoms and one oxygen atom. It has a chemical formula of H20 where the ratio of the two different atoms it is made up of two to one ie two atoms of hydrogen and one atom of oxygen covalently bonded to each other. Water is one of the most abundant of the smaller molecules and makes up to 60-90% of the fresh mass of an organism. Survival of all living organisms on earth hence is dependant on water. Therefore it is quite vital to understand the properties of water that makes it important to all living organisms. Polarity Of all the properties of water, polarity can be considered very important as it somehow contributes to almost all the other properties in one way or the other. Water is polar substance because it shows uneven change distribution within its molecule. One part of the water molecule is partially positive and the other is partially negative and this is known as a dipole. The polarity of water occurs because the oxygen atom in the molecule has greater electron attracting power than hydrogen atoms. Hence, oxygen has a slightly negative charge as compared to the hydrogen atom. The polarity makes water molecules to have weak force of attraction for each other, the opposite charges come together making the molecules behave as though they were sticky like magnets. The above property enables water posses several unique properties such as:- High Surface Tension Surface tension comes about due to forces of attraction between molecules of a liquid at its open boundary surface. In a water molecule however the high surface tension is due to unequal distribution of hydrogen bond at the surface of water. Hydrogen bonds exist between each water molecule of water, but molecules at the surface of liquid water have fewer neighbors and as a result, have greater attraction to the few water molecules that are nearby. The surface tension makes the surface of water slightly difficult to break through thou the interior. This is very important to living organism such as plants. As the water required for health plants is obtained from the soil which is down the plant, the high surface tension of water enables water to be pulled up a narrow tube by gravity without breaking its surface. â€Å"Cohesion of water molecule gives water a high tensile strength which enables water column in xylem elements of stem to be pulled upon to the top of tall trees without breaking.† Jain V.K, 2011:24. Surface tension is also responsible for the survival of small organisms that are dependent on the water surface as a mode of transport and living. The Basilisk lizards for instance, makes use of the high surface tension of water to accomplish the incredible feat of walking on waters surface. Some insects also are capable of moving on top of water without its surface breaking. Humans are also capable of skipping rocks on water. Low viscosity However, despite water having a high surface tension, water has a low viscosity. It is capable of sliding over each other easily. This property enables blood to move through thing capillaries and cytoplasm inside cellular boundaries. in animals, the capillaries are the smallest blood vessels found within the tissues of the body and are the ones that transport blood to larger vessels, for instance during gaseous exchange oxygen from the lungs is delivered to the capillaries around the air sacs to reach the blood inside it which latter is transported to the heart inorder to be pumped to all other blood’s mayor components is water this function of the capillaries is well carried out and animals such as human beings, survive. Therefore the low viscosity of water is important to human survival. not only what has been mentioned above, but also when molecules of others substances dissolve in mater, they low the surface tension of water and they tend to collect at the interface between the liquid phase and other phases. vermar and ararwal, 1974. this fact make water important in the development of a plasma membrane and aids the movement of molecules between it. Water is a universal solvent Water is referred to as a universal solvent as it is able to dissolve a wide range of substances dues to its polarity nature. Water dissolves substances by surrounding charged particles and pulling them into solution. It decreases the electro static interactions between charged substances and increasing yheir solubility. This property is very important to both plants and animal. According to verma and Agrival 1974:75. â€Å"The sol-valency is of great biological importance because all the chemical reactions that take place in the cells, do so in acqueous solution.† these solutions have the solvent water. This simply means that without water, biochemical reactions can not take place. All water alet acts as a transport medium, it is responsible for the transportation of all dissolved materials in blood such as food substances, gases excretory products and many other essential; and wastes products. in plants, it transports mineral salts and other nutrients to where they are needed. Water is a solvent for polar substances meaning that it does not dissolve non polar substances. This is of great importance in the formation of membranes and helps to determine the three dimensional properties of molecules of proteins, nucleic acids and their cel structure. Taylaor et al 1997. High capillarity The tendency of water to move up a narrow tube against the force of gravity is referred to as capillary action water has a high capillarity action water has s high capillarity. The high capillarity of water is due to its adhesives and cohesive forces. Cohesion is the mutual attraction between like molecules, water has cohesive properties as the molecules of water attract other water molecules. This is important in the transportation of water through a plant. Mader S. 2010:29 states â€Å"because water molecules are cohesive, a tension created that pulls the water column up from the roots.† the roots are anchored in the soil where the plant obtains water from. as the plant continuously transpierce through leaves which are up the plant, the water evaporating is immediately replaced with water molecules from the transport vessels from the roots to leaves. Adhesion, however, is the attraction between the water molecules and the container in which it is. Adhesion can also be described as the ability of one thing to stick firmly to another. Water is therefore attracted to substances such as cells walls, or glass surface. This is also important to living organisms. In the transport of water to the wall of the vessels also help in preventing the column of water from breaking apart. In general, adhesive and cohesive properties of water work hand in hand in the movement of water from the roots up to the leaves. Specific heat capacity Water has a high heat capacity, specific heat capacity is the amount of energy that must added to a unit mass to raise the temperature by one degree, and â€Å"the high specific heat capacity of water is due to the hydrogen bonds between the molecules. Water absorbd a lot of heat before it begins to get hot. The above property is important to organism that line in water such as fish. water organisms do not die due to excess heat and coldness as it take time for water to gain and lose heat, hence the temperature is well maintained for water life. According to Mader 2010:29, â€Å"because the temperature of water rises and falls slowly, organisms are better able to maintain their normal internal temperatures and are protected from srapid temperature changes.† most of the chemical reactions in cells take place within a small range of temperature. Transparency Water is idourless, hence transparent. This property is also very important as it enables tight to penetrate through it and reach photosynthetic organalles, the chloroplast inside cells which require sunlight to manufacture food.. Having discussed the above property of water, and this importance to all living organisms, it can be concluded that without water, life on earth is practically impossible as all living organisms depend on water. BIBLIOGRAPHY Jain V.K. (1974); Fundamentals of plant Physiology, S. Chand and Company Ltd. New Delhi. Kormondy E.J (1996); Concepts of Ecology, Fourth Edition. Pearson Education New Jersey. Mader S.S (2010); Biology, tenth Edition. McGraw – Hill Education. Singapore. Taylor D.J et al (1997); Biological Science 1 and 2 third edition. Camridge University Press. New York. Verma P.S and Agarwal V.K. (1974); Cell Biology, Genetics, Molecular Biology, Evolution and Ecology, Multicolour edition. Rejendra Ravindra Printer New Delhi. An Avocado Is A Fruit: Analysis An Avocado Is A Fruit: Analysis An avocado is a fruit and not a vegetable that grows on a tree and can be technically classified as a berry. The avocado is from evergreen tree which is native to Mesoamerica. Its natural range covers diverse environmental conditions from the central highlands of Mexico where frosts occur to the rain forests of northwest Columbia. They have a taste that ranges from rich, creamy and buttery to light and fruity, depending on the variety. There are many varieties of avocados, several of which are grown commercially. The Hass variety is the most popular commercially grown variety and has a deep, rich flavor. Avocados are ready to eat when they are slightly soft and yield to gentle pressure. The skin is peeled away and the flesh of the fruit is eaten. Avocados can be eaten by themselves or used for guacamole, sandwiches, salads, omelets, desserts and much more. (Smith et al. 1992,) History In 1519, Spanish soldier of fortune Hernando Cortez (1485-1547) set foot in Mexico City, the first white man to do so. Cortez found that the avocado. The avocado is native to the area stretching from the eastern and central highlands of Mexico through Guatemala to the Pacific coast of Central America. There is evidence that avocados have been utilized in Mexico for 10,000 years. The Spanish Conquistadors were the first Europeans to discover the fruit, native to the Americas, which the indigenous people of Mexico, Central America and South America had been using for thousands of years. Avocado its name comes from Latin America Nahunta word, meaning testicular fruit shape obvious reference. It is found in Mexico about 291 BC avocado easier to significant name because Sir Henrys Sloan, who created it in 1669. Naturalist Sir Hans Sloan was the first to use the name avocado, in a catalogue of Jamaican plants he published in 1696. During the 1700s, European sailors used the avocado as a spread for biscuits, which led to the name midshipmans butter. Avocado trees were introduced to California by 1856, when tree brought from Nicaragua was noticed growing near San Gabriel. In 1911, Carl Schmidt, a plant explorer, collected bud wood of a seedling that eventually became the Fuertes. This variety was the basis of the California avocado industry for many years. Avocados were introduced in Florida by 1850, and, in the 1930s, autumn and winter varieties were adapted. While commercial varieties of avocados arrived in Chile from California in 1928, avocados have been growing in that country since colonial times. The avocado arrived in Indonesia in 1750, Brazil in 1809, Israel in 1908, and South Africa and Australia in the late 19th century. In the late 1920s, Mr. Rudolph Hass discovered what would become the Hass variety. It is currently the most widely grown commercial and popular avocado variety. Early Spanish explorers found Aztecs enjoy avocado, but it has long been considered a tasteless food. The Aztecs also used avocados as a sexual stimulant. This is Spanish explorers brought avocado English. The first Florida crop included to the gardener Henry Ryan plantation in 1833. However, avocado and did not become a commercial crops, until the 20th century. Except in California, Florida, Hawaii, they generally planting, most consumer exit from the fruit. Finally, in the 1950 s, avocado to become popular for salad project and consumption become more common. In 1995, 40.9% of American families consumed of avocado. (Peggy, 2012) Geography map.png Mexico is the world leader for avocado growing, accounting for almost 35% of global production. Other important avocado producers include the USA and Indonesia (each with 7% of the world total), Colombia (6%), Brazil (5%) and Peru (4%). Land Aspects- Frost free, is the ideal avocado north, there is a warm climate. The site should be flat, or of a very slight slope, to allow easy mechanical access. Climate- Growth and fruit appropriate temperature is the most important requirement, the successful development of avocado. Suitable for planting avocado microclimate temperature must meet the following requirements: Occasional winter frosts warmer than -4 °C Day temperatures above 19 °C during flowering (September to November) Night temperatures above 10 °C during flowering No frosts during flowering Soil- Soil The avocado tree has shallow feeding roots that need a good permeability and well drained soils. Ideal soil should have the following features: A depth of more than 1.5m Be uniform and free draining Not be compacted or have impervious layers Have moderate fertility Have a high organic matter component Wet poorly drained soils will lead to major problems with root rot Types of avocado Hass Avocados Hass avocados are commonly seen year-round in the United States and some other areas. Generally easy to peel and usually weigh between 5 and 12 oz. Bacon Avocados Bacon avocados are common in the mid-winter months when other varieties are less prevalent. Bacon avocados have a fairly thin green skin that only gets slightly darker when they reach full maturity. Bacon avocados are usually about 6 to 12 oz. Fuerte Avocados The fuerte avocado is harvested from late autumn to early spring. The fuerte variety was the most common in the western part of the United States, which is oval shaped, the fuerte has a pear shape. Reed Avocados Reed avocados are large, round avocados that usually weigh between 8 and 18 oz. and are widely available in the summer months. Pinkerton Avocados Pinkerton avocados grow in the winter and yield more fruit than most avocados because of their small seeds. Approximately 8 to 18 oz. (Peggy, 2012) Propagation, Planting, Harvesting Propagation Seeds: Rapidly lose their viability: ~28 days. Fresh seeds germinate in 4-6 weeks. Seeds germinate well if placed in warm, moist compost and are only partially buried. You can remove the brown seed coat and cut a thin slice off the apex and base of the seed to aid germination. When roots and leaves are well formed, carefully plant seedlings in deep pots to establish before planting out. Avoid repotting to avoid root damage. Progeny from seedlings are variable. Cuttings: Generally difficult. Layering: Air-layering is successful with some cultivars, with Mexican-types rooting well. This is best done in spring and early summer. Grafting: Grafted or budded trees are more predictable in quality. Grafting is mainly done by whip, side- or cleft- grafting. Mexican- type rootstocks make the strongest growth, are hardier and are often used. Trees are sometimes top- worked. Planting Space plants at least 6-7 m apart; branches can die back if they touch those of their neighbor. Trees benefit from organic mulch, and from staking until established. Best site in a protected, warm area. Harvesting Avocados are harvested with hand-held poles and baskets. In flat areas in California, man-positioning machines are used to lift the pickers. Fruits are picked when mature but still hard. Determining when to harvest avocados can be difficult and may require experience. A slight change in skin color, loss of glossiness, or a brown seed coat is a sign of maturity. Pruning shears or special clippers should be used to harvest avocados. The pedicel should also remain attached to the fruit. (Chia, C. L. et. al. and Yokoyama, K. M., et. Al, 2009) Culture European sailors used the avocado as a spread for biscuits, which led to the name midshipmans butter. In Japan sushi avocado dishes are well-liked in international cuisine. Early Spanish explorers found Aztecs enjoy avocado, but it has long been considered a tasteless food. The Aztecs also used avocados as a sexual stimulant. Culinary (Unknown, 2004) Slices of avocado are widely served in sandwiches and on toasted bread as a snack. Even avocado puree has varied uses such as it can be spread in hotdog and hamburgers and also used as a thickener in various liqueurs. Sushi avocado dishes are well-liked in international cuisine. Being a fruit, avocado is used for various culinary purposes but it is popularly eaten raw or added to various fruit salads in raw form. The subtle-flavor and creamy texture of the fruit makes it a very popular ingredient of avocado recipes such as avocado juice, avocado salad and avocado dip. All these avocado dishes are well-liked in almost all households. Various seasonings and spices can be mixed in the avocado dips to provide flavor to the dish. In the list of sweet dishes, avocado recipes are quite popular. It is often included in several ice creams and milkshakes and other desserts. Salads and juices are some other additions to the list of avocado dishes. In savory dishes also avocado is a well-liked ingredient. Medical/Non- Culinary (Ruby S, 2009-2012) From the ancient times avocado is used as an excellent beauty aid. They truly offer wealth of health and significant beauty benefits. You can easily use Avocado in your daily beauty routine and save some money too. Here are the various beauty uses of Avocado. Take one avocado, half teaspoon of olive oil and one egg yolk. Mash it thoroughly in a bowl. Apply this mix to wet or damp hair. Leave it on for 20 to 30 minutes. Massage it in your scalp properly. Rinse with warm water and shampoo your hair as usual. So can Amazing soft, silky and shiny hair. It is also believed to be an effective sexual stimulant and is used to make ointments aimed at delaying old age. Change Agents Hernando Cortez- In 1519, Spanish soldier of fortune Hernando Cortez (1485-1547) set foot in Mexico City, the first white man to do so. Cortez found that the avocado was a staple in the native diet European sailors- In 1700s, European sailors in the 1700s called it midshipmans butter because they liked to spread it on hard tack biscuits Manashita Ichiro- Avocado in sushi was the idea of a Japanese chef Manashita Ichiro in Los Angeles about 40 years ago who used it as a replacement for Toro because it offered a similarmalty mouth feel ¼Ã…’It was subsequently used in California rolls. Its a Japanese invention. Innovation (April, 2011) Avocado oil- Avocado oil may have anti-ageing properties like those attributed to olive oil. Avocado oil is very rich in monounsaturated fatty acids and extremely low in saturated fat. It also contains no cholesterol. Avocado Face Mask- Gives deep cleansing which helps in getting rid of the dirt and grime accumulated on the face, it opens up the tiny ducts for cleansing and clearing the dead skin cells and thereby prevents acne breakouts. Avocado Sushi- Avocado in sushi was the idea of a Japanese chef in Los Angeles about 40 years ago who used it as a replacement for Toro because it offered a similarmalty mouth feel ¼Ã…’It was subsequently used in California rolls. Avocado Butter- Our Avocado Butter s produced by hydrogenating cold pressed Avocado Oil with other vegetable oils. The light hydrogenation process creates butter with good oxidative stability and a smooth, silky feel. Nutrition Per 230g avocado including Calories 384 KJ, Fat 55%, cholesterol 0%, Sodium 1%, Carbohydrate 7%, Protein 5g, Vitamin A 7%, Vitamin C 34%, Calcium 3%, Iron 8%. (Unknown, 2010-2012) Resources (Unknown, 2012) Human Resources- Natural Resources- Avocado growing need air, sunlight, water, soil, especially free frosts and warm climate. Wet poorly drained soils will lead to major problems with root rot. Mechanical Resources- Workers can use man-positioning machines to lift them to pick mature fruit. Future Trends Contemporary uses Current applications (Unknown, 2004) In bakery to avocado flavor cakes, biscuits and bread. In Japan, sushi avocado dishes are well-liked in international cuisine. Being a fruit, avocado is used for various culinary purposes but it is popularly eaten raw or added to various fruit salads in raw form. In restaurant, various seasonings and spices can be mixed in the avocado dips to provide flavor to the dish. It is often included in several ice creams and milkshakes and other desserts. Salads and juices are some other additions to the list of avocado dishes. In savory dishes also avocado is a well-liked ingredient.