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...
Biosynthesis of fatty acids 1. Biosynthesis of fatty acids occurs in all organisms and in mammals it occurs mainly in adipose tissue, mammary glands, and liver. 2. Fatty acid synthesis takes place in the cytosol in two steps. · Formation of medium chain fatty acid of chain length 16 carbon atoms. · Lengthening of this carbon chain in microsomes for larger fatty acids. 3. Acetyl CoA serves as a source of carbon atoms for saturated as well as unsaturated fatty acids. Acetyl CoA can be formed from excessive dietary glucose and glucogenic amino acids (amino acids which can be converted to glucose). Carbohydrates and ami...
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