anabolism Anabolism is the building up or biosynthesis, of complex molecules such as protein, nucleic acids and polysaccharides, from raw materials originating from intra-or extracellular sources. The biosyntheses are energy (aTP)requiring processes. Catabolism and anabolism have to be carefully regulated and are inevitably intimately t are the three areas where the processes of catabolism and anabolism are Catabolism produces ATP, reducing power and intermediates. Anabolism requires all three, thus these are the three main links. No living cells can store large amounts of ATP. There is a finite amount of adenine distributed between AMP, ADP and ATP. Thus if the cell has a relatively high concentration of atP, the concentrations of AMP and/or ADP must be lowered. The balance alters like a"see-saw", as one goes up the other must come down. In addition the total amount of nad/NADH and NadP/NAdPH in the cell is constant. What is the advantage of the see-saw type of change to the ratio of the The answer is that such a system is far more sensitive to small changes in concentration of the respective compounds. The cell is recognising a change of the ratio of compounds, rather than the rise or fall of a single compound Although cells cannot store ATP, they must always have a minimum amount available to keep them alive. Thus a constant level of ATP must be maintained indicating that catabolism and anabolism occur constantly under normal conditions ∏ One compound controls the overall metabolism of the cell regulating and balancing anabolism and catabolism. Can you name it? The answer in practice is aTP though you would have been theoretically correct if you had said ADP and AMP. Indirectly, NAd or NADH are also compounds which regulate the anabolic/catabolic balance The metabolic control is exercised on certain key regulatory enzymes of enzymes called allosteric enzymes. These are enzymes whose catalytic activity is hrough non-covalent binding of a specific metabolite at a site on the protein the catalytic site. Such enzymes may be allosterically inhibited by aTP or all activated by ATP (some by ADP and /or AMP). Thus atp is the effective controller of metabolism but because AMP ADP + AtP is constant, it is really the ratio of adenine nucleotides which is important. This ratio is energy charge termed the adenylate charge or energy charge and is expressed as Energy charge 0.5 [ADP]+ [ATPI [AMP]+[ADPI+ [ATPI122 Chapter 5 anabolism albsteric enzymes Anabolism is the building up or biosynthesis, of complex molecules such as protein, nucleic acids and polysaccharides, from raw materials originating from intra- or extracellular sources. The biosyntheses are energy (ATP) requiring processes. Catabolism and anabolism have to be carefully regulated and are inevitably intimately linked. What are the three areas where the processes of catabolism and anabolism am n linked? Catabolism produces ATP, reducing power and intermediates. Anabolism requires all three, thus these are the three main links. No living cells can store large amounts of ATP. There is a hite amount of 'adenine' distributed between AMP, ADP and ATP. Thus if the cell has a relatively high concentration of ATP, the concentrations of AMP and/or ADP must be lowered. The balance alters like a "see-saw", as one goes up the other must come down. In addition the total amount of NAD+/NADH and NADP+/NADPH in the cell is constant. What is the advantage of the see-saw type of change to the ratio of the n concentrations? The answer is that such a system is far more sensitive to small changes in concentration of the respective compounds. The cell is recognising a change of the ratio of compounds, rather than the rise or fall of a single compound. Although cells cannot store ATP, they must always have a minimum amount available to keep them alive. Thus a constant level of ATP must be maintained indicating that catabolism and anabolism occur constantly under normal conditions. One compound controls the overall metabolism of the cell regulating and n balancing anabolism and catabolism. Can you name it? The answer in practice is ATP though you would have been theoretically corred if you had said ADP and AMP. Indirectly, NAD+ or NADH are also compounds which regulate the anabolic/catabolic balance. The metabolic control is exercised on certain key regulatory enzymes of a pathway called allosteric enzymes. These are enzymes whose catalytic activity is modulated through noncovalent binding of a specific metabolite at a site on the protein other than the catalytic site. Such enzymes may be allosterically inhibited by ATP or allosterically activated by ATP (some by ADP and/or AMP). Thus ATP is the effective controller of metabolism but because AMP + ADP + ATP is constant, it is really the ratio of adenine nucleotides which is important. This ratio is termed the adenylate charge or energy charge and is expressed as: 0.5 [ADP] + [ATP] [AMP] + [ADP] + [ATPI Energy charge =