Homeostasis
Biological organisms are constantly adding acids to their bodily fluids during metabolism, but our blood is slightly basic.
- Intra- and extra-cellular buffers operate to maintain homeostasis.
- Buffers minimize changes of pH in solutions; they reversibly donate or accept hydrogen ions.
- Example: Bicarbonate buffer system:
- If the extracellular fluid becomes too basic, the reaction can be reversed:
Buffers
- * Write that buffers minimize changes of pH in solutions;
- They reversibly donate or accept hydrogen ions.
- For example, consider the bicarbonate buffer system:
- When hydrogen ions are added to the extracellular fluid, they combine with bicarbonate to produce carbonic acid, which is a weaker acid.
- Or, if the extracellular fluid becomes too basic, the reaction can be reversed:
- Carbonic acid can dissociate to form hydrogen ions and bicarbonate.
- When pH increases (becomes more alkaline), carbonic acid dissociates to form bicarbonate, which is a base, and hydrogen ions.
- When pH decreases (becomes more acidic), the equation is reversed: bicarbonate and hydrogen ions combine to form carbonic acid.
However, if the body cannot maintain homeostasis due to pathology, disturbances in bodily fluid pH have clinical consequences:
- The enzymes that facilitate chemical reactions in our bodies are only active within specific blood pH ranges; outside of those ranges, the chemical reactions are inhibited.
- Thus, failure to regulate pH causes a range of clinical symptoms associated with acidosis (too high blood acid content) or alkalosis (too low blood acid content); elsewhere, we discuss how the kidneys and lungs work to maintain homeostatic pH levels.