The initial steps in glycolysis, which provide for the entry of glucose and glycogen, are under humoral control; those toward the middle of these pathways are regulated mainly by energy requirements, whereas the reactions toward the end of this pathway, which require substrate oxidation, respond to the supply of oxidized coenzymes. The most long - lasting control, which involves changes in enzymes whose expression is alterated in chronic disease, is exerted at several steps in this pathway. According to the monetary analogy these control mechanisms are analogous to thouse that regulate capital flow through a bank account. Expenditures are determined first by the desire to spend (hormones and neurotransmitters), secondly by the balance in the account (high energy phosphates), thirdly by reserves that can be converted to cash (supply of oxidised coenzymes), and ultimately by earning capacity (levels and isoforms of key glycolytic enzymes).