LIVING CELL Introduction The cell is the basic structural and functional unit in all living organisms. Living forms vary in size but they are all made up of cells. In unicellular organisms, the cell is the organ. As an organism grow in complexity, the cells increase in number and similar cells aggregate into tissues and organs with specialized functions. The shape of the cell is often determined by its function and the size of the cell is determined by the optimum dimensions that will enable it to perform its duties more effectively . The human body is composed of a multiple of specialized tissues which inturn consist of vast clusters of cells differentiated into specialised chemical factories which perform various biochemical reactions. Types of cells Two general types are recognised in nature. They are prokaryotic and eukaryotic cells. Prokaryotic cells Prokaryotes were the first cells to arise in biological evolution. They are very small and simple having only a single membran...
Derivation of M - M Equation Leonor Michaelis and Mand L. Menton in 1913 proposed a successful explanation for the effect of substrate concentration on the enzyme activity. According to them the enzyme E , and the substrate S combines rapidly to form a complex, the enzyme substrate complex ES. This complex then breaks down relatively and slowly to form the product P of the reaction .These sequence of reactions can be represented in the following equations o K 1 & k 2 are the rate constants of the forward and backward reactions (step 1) o K 3 & k 4 are the rate constants of the forward and backward reactions respectively (step2) This is true only for the enzyme reactions which fulfill the following conditions: i. only a single substrate and a single product a...
Oxidation of Fatty Acids The digestion of fats starts in the small intestine. Fats are emulsified by the bile salts and hydrolysed by the pancreatic lipases to form free fatty acids. These free fatty acids combine with glycerol (produced by the glycolytic process) to form triglycerides. They combine with proteins to form lipoproteins and enter into circulation to perform various biolological functions such as oxidation, storage and formation of new lipids. Thus the various fatty acids may exist in the free form as well as in the esterified form (Triglyceride) in blood. Fatty acids are the immediate source for oxidation of fats in various tissues viz. liver, adipose tissue, muscles, heart, kidney, brain, lungs and testes. 1. β -Oxidation Fatty acids are oxidised to CO 2 and water with the liberation of large amount of energy. Oxidation is brought about in the mitochondria because all the enzymes required for oxidation are present in the mitochondria. Oxida...
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