Final answer:
The one effect not related to changes in pH on the body is the alteration in water balance, which is more directly influenced by electrolytes than pH.
Step-by-step explanation:
The effect that is NOT one of the consequences of changes in pH on the body is 'alteration in water balance'. This is because water balance is primarily influenced by electrolytes and their osmotic gradient rather than directly by pH changes. However, alterations in pH can greatly affect other physiological activities including protein function, central nervous system activity, potassium homeostasis, and cardiac rhythm. Enzymes, central nervous system signaling, skeletal muscle function, and cardiac muscle contraction can all be disrupted by pH deviations from the optimum. Potassium ions are especially relevant as they play critical roles in nerve conduction and muscle function, including the heart, making pH a critical factor in potassium homeostasis and consequently in cardiac rhythm.