Nutritional Requirements 125 Biochemically, energetic coupling is achieved by the transfer of one or both of the terminal phosphate groups of AMP to an acceptor molecule, most of +ATP→ glucose6 phosphate+AD②J the bond energy being preserved in the new ormed molecule, e. g, glucose Mammalian skeleton muscle at rest contains 350-400 mg ATPper 100 g. ATP inhibits enzymatic browning of raw edible plant materials, such as sliced apples 2.0 NUTRITIONAL REQUIREMENTS OF THE CELL Besides a source of energy, organisms require a source of materials for biosynthesis of cellular matter and products in cell operation, maintenance and reproduction. These materials must supply all the elements necessary to ccomplish this. Some microorganisms utilize elements in the form of simple compounds, others require more complex compounds, usually related to the form in which they ultimately will be incorporated in the cellular material The four predominant types of polymeric cell compounds are the lipids(fats) the polysaccharides(starch, cellulose, etc. ) the information-encoded polydeoxyribonucleic acid and polyribonucleic acids dNa and rNA), and proteins. Lipids are essentially insoluble in water and can thus be found in the nonaqueous biological phases, especially the plasma and organelle membranes. Lipids also constitute portions of more complex molecules, such as lipoproteins and liposaccharides. Lipids also serve as the polymeric biological fuel storag Natural membranes are normally impermeable to highly charged chemical species such as phosphorylated compounds. This allows the cell te contain a reservoir of charged nutrients and metabolic intermediates, as well as maintaining a considerable difference between the internal and extemal concentrations of small cations such as h. K and Nat. Vitamins.EK and D are fat-soluble and water-insoluble. Sometimes they are also classified as lipids DNA contains all the cells hereditary information. Upon cell division, each new cell receives a complete copy of its parents'DNA. The sequence of the subunit nucleotides along the polymer chain holds this information Nucleotides are made up of deoxyribose, phosphoric acid, and a purine or cleotides. rogenous base. RNA is a polymer of ribose-containing Of the nitrogenous bases, adenine, guanine, and cytosine areNutritional Requirements 125 Biochemically, energetic coupling is achieved by the transfer of one or both of the terminal phosphate groups of AMP to an acceptor molecule, most of the bond energy being preserved in the newly formed molecule, e.g., glucose + ATP + glucose-6-phosphate + ADP.['] Mammalian skeleton muscle at rest contains 350-400 mg ATP per 100 g. ATP inhibits enzymatic browning of raw edible plant materials, such as sliced apples, potatoes, etc. 2.0 NUTRITIONAL REQUIREMENTS OF THE CELL Besides a source of energy, organisms require a source ofmaterials for biosynthesis of cellular matter and products in cell operation, maintenance and reproduction. These materials must supply all the elements necessary to accomplish this. Some microorganisms utilize elements in the form of simple compounds, others require more complex compounds, usually related to the form in which they ultimately will be incorporated in the cellular material. The four predominant types of polymeric cell compounds are the lipids (fats), the polysaccharides (starch, cellulose, etc.), the information-encoded polydeoxyribonucleic acid and polyribonucleic acids (DNA and RNA), and proteins. Lipids are essentially insoluble in water and can thus be found in the nonaqueous biological phases, especially the plasma and organelle membranes. Lipids also constitute portions ofmore complex molecules, such as lipoproteins and liposaccharides. Lipids also serve as the polymeric biological fuel storage. Natural membranes are normally impermeable to highly charged chemical species such as phosphorylated compounds. This allows the cell to contain a reservoir of charged nutrients and metabolic intermediates, as well as maintaining a considerable difference between the internal and external concentrations of small cations, such as H', Kf and Na'. Vitamins A, E, K and D are fat-soluble and water-insoluble. Sometimes they are also classified as lipids. DNA contains all the cell's hereditary information. Upon cell division, each new cell receives a complete copy of its parents' DNA. The sequence of the subunit nucleotides along the polymer chain holds this information. Nucleotides are made up of deoxyribose, phosphoric acid, and a purine or pyrimidine nitrogenous base. RNA is a polymer of ribose-containing nucleotides. Of the nitrogenous bases, adenine, guanine, and cytosine are