Which of the following is an example of a biological buffer found in the body?

Bicarbonate is a key biological buffer in the human body, playing a crucial role in maintaining the pH balance within the blood and other fluids. It functions primarily through the bicarbonate-carbonic acid buffering system, which helps to neutralize excess acids or bases. In this system, carbonic acid can dissociate into bicarbonate and hydrogen ions, allowing the body to respond to changes in pH. When the pH drops (becomes more acidic), bicarbonate can accept hydrogen ions to reduce acidity; conversely, when pH rises (becomes more basic), carbonic acid can release hydrogen ions, lowering pH back to normal levels.

This buffering capacity is vital for numerous physiological processes, including respiration and metabolism, and plays an essential role in preventing harmful fluctuations in blood acidity that could disrupt cellular function.