Arsenate (AsO₄ ^3–) is chemically very similar to phosphate (PO₄^3–) and can be used as an alternative substrate by many phosphate-requiring enzymes. In contrast to phosphate, however, an anhydride bond between arsenate and carbon is very quickly hydrolyzed nonenzymatically in water. Knowing this, suggest why arsenate is a compound of choice for murderers but not for cells. Formulate your explanation in th context of Figure 13–7.

Figure 13–7

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formation of NADH NAD+ C-H bond oxidation energy STEP 6 H+ + NADH H 1,3-bisphosphoglycerate OW P formation of high-energy phosphate bond P breakage of high-energy phosphate bond STEP 7 ATP OH formation of ATP ADP glyceraldehyde 3-phosphate 3-phosphoglycerate OXIDATION OF AN ALDEHYDE (-COH) TO A CARBOXYLIC ACID (-COOH) TOTAL ENERGY CHANGE (AG) for step 6 followed by step 7 is a favorable -12.5 kJ/mole