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Friday, March 5, 2010

Life Components (Inorganic and Organic)

Life Components (Inorganic Compounds)
A cell is composed of a variety of molecules called Bio molecules. The Bio molecules determine the structure and functions of different cells. Aggregation of various types of bio molecules in a cell is called the cellular pool. The cellular pool is composed of both inorganic and organic molecules. Bio molecules are micro molecules and macromolecules.

Micro molecules
Micro molecules are the substrates and products of metabolism in a cell. It includes inorganic compounds like water, minerals and gases and organic compounds like sugars, lipids, amino acid and nucleotides.

Water:
It constitutes 60.80% of the cell contents and 75-90% of the protoplasm. Water is the abundant compound of the living beings.

Minerals:
Minerals constitute about 1-3% of the cell contents but are very essential for life activities. Essential minerals required in large quantities for proper growth and metabolism are called macronutrients. They include Ca, S, P, Mg, Fe, K. Minerals required in small quantities are called micronutrients. They include Co, Mn, Mo, Zn and Cl. Some minerals acts as buffers and maintain acid base balance in the cell and extracellular fluid.

Gases:
Gases form less than 0.5% of the cell contents. They include O2, Na, CO2, and NH3. These gases being soluble in water, occur is dissolved state.

Macromolecules
Macro molecules have a complex molecular structure and occur in colloidal state. They are insoluble in intracellular fluid and formed by polymerization of micro molecules. They include only organic compounds such as polysaccharides, protein and Nucleic Acids.

Organic Compounds
Organic Compounds are carbon containing compounds, and make up about 95% of the dry weight of the protoplasm. It includes sugar, lipids, amino acids and Nucleotides.
Carbohydrates
Carbohydrates constitute about 1% of the cell contents. They are compounds of carbon, hydrogen and oxygen in the ratio of 1:2:1. Glucose is the Universal sugar and is also known as dextrose or grape sugar. It is the main source of energy in the cells and is the blood sugar in most of the animals. Fructose is the fruit sugar and is also known as levulose. It is the sweetest among the naturally accruing sugars. Maltose, Sucrose and Lactose are common disaccharides. Maltose or malt sugar formed in germinating seeds. Sucrose is the common cane or table sugar (product of photosynthesis). Lactose or milk sugar is found mammalian milk.

Lipids
The lipids constitute 3.5% of cell contents. They are C, H and O compounds but are poorer in oxygen. They are in soluble in water and on oxidation yield maximum energy. Lipids are Life Components (Inorganic and Organic)proteinthe food reserves of plants and animals. The fats form insulting layer under the body skin and help to conserve the body heat.

Amino Acids
Amino acids are building blocks of proteins. They are made up of C, H, O and sometimes of S. There are 20 amino acids which are normal, components of cell proteins. Animals cannot synthesize all the amino acids, they require some in ready form in the food. These are called essential amino acid. eg. Lysine, Leucine, Valine, Tryptophan, etc.

Nucleotides
Nucleotides constitute about 2% of the cell contents. The nucleotides polymerize to form DNA and RNA. Specific sequence of nucleotides in DNA codes for specific amino acids required for protein synthesis. In addition with phosphate nucleotides form energy carriers such as ADP and ATP. Nucleotides take part in the formation of coenzymes by replacing their nitrogen base group with some vitamin. NAD, NADP, FMN, FAD and co-enzyme. A are some important coenzyme.

Micro molecules
Micro molecules are large, complex and have high molecular weight. Polysaccharides, proteins and nucleic acids are the most important macromolecules. They are polymers of sugars, amino acids and nucleotides respectively.

Polysaccharides
Monosaccharides are joined together by glycoside bonds with a loss of water molecule. They consists of more than six molecules of a monosaccharides (usually glucose). Homopolysaccharides: Contain monosaccharides of single type eg. Glucose (Glycogen-in animals, and starch and cellulose in plants). Heteropolysaccharides: Composed of modified monosaccharides. It includes mucopolysaccharides, glycoprotein and chitin. Hyaluric Acid, Heparin, Chondrotin Sulphate and Keratin Sulphate are mucopolysaccharides.

Proteins
Proteins constitute about 12%of cell contents and form nearly 75% of the dry weight of the most cells. They are linear, un-branched polymers of amino acids. They are structural basis of cells and helps in growth repair and maintenance. All enzymes, antibodies and some hormones are also proteins.

Nucleic Acids
Nucleic acids are strong acids mainly present in the nucleus and in lesser quantities in mitochondria, plastids and cytoplasm. Nucleic acids are linear, unbranched, nucleotides polymers polynuc leotides.
Life Components (Inorganic and Organic)rna
Deoxyribonucleic Acid (DNA)
DNA has adenine, guanine, cytosine, thymine and thymyde. DNA has the blue print for all the hereditary characters of an organism. It has a double helical structure with two antiparallel strands held by H-bonds.

Ribonucleic Acid (RNA)
RNA has uracil instead of thymine; adenine and cytosine are also present. They are single stranded and play an important role in protein synthesis. They are of three types: r-RNA, m-RNA and t-RNA.

2 comments:

Unknown said...

you saved me from my biology class. thanks!

Unknown said...

My also

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