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Friday, 16 January 2015

Understanding The Complexities of Carbohydrate As An Organic Compound

Organic compounds are covalent compounds that derive much of their characteristic from carbon which is the main element in them. Carbon forms  4 covalent bonds when they go into a chemical reaction. Carbon uses this ability to form covalent bonds with other elements or compounds to form long chain atoms of organic compounds, forming several compounds in the process with varying degrees of complexity.

Carbohydrates are a group of organic compounds that can occur both as sugars and starch. During their breakdown, they yield energy which is very essential in every living thing. They can also combine chemically to form various compounds and structures especially in the cellulose cell walls of plants. Elements present in carbohydrates are carbon, hydrogen and oxygen combined in the ratio 1:2:1. This goes to show that a simple sugar such as glucose generally has the formula(general formula) of  (CH2O)n where n signifies the total number of carbon, hydrogen and oxygen atoms present in that compound. 

If the n represents 6, then it means that the resulting carbohydrate would be a hexose sugar i.e C-6H-12O-6 which is the formula for glucose. If n is 5 then a pentose sugar is formed, C-5H-10O-5. It can therefore form a homologous series to produce several other compounds of similar physical properties and varying chemical complexities.



                                        Formation of Complex Carbohydrates

The hexoses are regarded as monosaccharides because they are simple sugars  with characteristics such as crystalizability, sweetness and solubility on water. Two monosaccharides can combine to form a disaccharide(two sugar groups) by a process known as condensation with the loss of water.

A covalent bond is formed when two monosaccharide molecules combine with the removal of a single molecule of water from the pair of monosaccharide molecules and this is achieved when a hydrogen atom coming from each of the hydroxyl groups of these monosaccharide molecules at positions 1 and 4 respectively and an oxygen atom from one of the two monosaccharide hydroxyl groups combine chemically which results in the formation of a covalent bond known technically, in this case, as a glycosidic bond which joins the two monosaccharide molecules at positions 1 and 4. 

The eventual molecule is a 1-4linked disaccharide molecule having a general formula of (C-12H-22O-11). This reaction is therefore reversible as under suitable conditions, the disaccharide can hydrolyze into its component monosaccharide sub-units.

Disaccharides formed depend on the monosaccharide units responsible for its formation. Sucrose, a disaccharide is formed from glucose and fructose. Sucrose is the main form by which carbohydrate is transported in plants and this sugar is abundant in the roots of sugar beet and in the stems of sugar cane.

Lactose, which is the sugar found in milk is formed from glucose and galactose while Maltose which occurs in germinating seeds of certain cereals such as sorghum and barley is formed from two alpha-glucose molecules.

Monday, 12 January 2015

Functions Of Mineral Salts And Their Derivatives In The Human Body

1. Mineral salts are constituents of structures: Proteins are involved in the formation of structures and connective tissues and fibres with sulfur and nitrogen been the main elements. Nitrogen and phosphorus which are constituents of nucleic acid can be found in abundance in the chromosomes. Phosphorus is found in bones and cell membrane while calcium is found in the cell wall of plants, bone tissues along with phosphorus.

2. They act as metabolic activators: Minerals act as activators of enzymatic activities during metabolism. Magnesium activates enzymes involved in a phosphate metabolism while phosphorus in the form of phosphate is required in the activation of sugar prior to its breakdown by the cells during cellular respiration.

3. As constituents of several chemicals: plants obtain nitrogen, sulphur and phosphorus in the form of nitrates, sulfates and phosphates. These compounds go into the metabolic formation of protein and other forms of complex amino acids macromolecules. Phosphorus is found in ATP( adenosine triphosphate) while iodine is found in the thyroid hormone known as thyroxin.

4. Minerals salts are constituents of enzymes: Enzymes are composed of various elements in form of salts, ions and compounds. Enzymes are proteins and all proteins contain nitrogen as a prominent element. The enzyme catalase is involved in various enzymatic reactions and contains the element iron.

5. Minerals are constituents of certain biological pigments: Heamoglobin and chlorophyll are prominent biological pigments that contain a wide range of minerals elements such as iron and magnesium respectively. Iron can also be found in cytochromes which are pigments involved in energy release during cellular respiration.

6. They act as determinants of osmotic pressure: mineral salts along with other forms of solute act as osmotic pressure determinant in cellular structures and body fluids. The osmotic pressure in man must not be allowed to fluctuate beyond the narrow limits even as much of the human physiology is directed towards preventing this to occur.

7. They determine the balance between anion and cation in cells: Potassium, sodium and chloride ions are particularly important in maintaining a balance between anion and cation especially in the nervous system where they play major roles in nerve impulses through the sensory and motor neurons and nerve fibres.