**Blood is Alkaline:**

Blood is classified as alkaline, meaning it has a pH value greater than 7. The pH scale measures the acidity or alkalinity of a substance, with 7 being neutral, values below 7 being acidic, and values above 7 being alkaline. The pH of blood is maintained within a narrow range to ensure proper functioning of the body.

**Buffering System:**

The pH of blood is primarily regulated by a buffering system, which consists of a combination of weak acids and their corresponding salts. This buffering system helps to maintain the pH stability of blood by resisting changes in acidity or alkalinity.

**Bicarbonate Ion:**

One of the major components of the buffering system in blood is the bicarbonate ion (HCO3-). Carbon dioxide (CO2) produced by cellular metabolism combines with water (H2O) to form carbonic acid (H2CO3), which quickly dissociates into bicarbonate ions and hydrogen ions (H+). The bicarbonate ion acts as a weak base, helping to neutralize excess hydrogen ions and maintain the alkaline pH of blood.

**pH Range of Blood:**

The pH of arterial blood, which carries oxygen from the lungs to the body tissues, is slightly alkaline and typically ranges from 7.35 to 7.45. This narrow range is crucial for maintaining the proper functioning of enzymes, proteins, and other biological processes within the body.

**Acid-Base Balance:**

The body has intricate mechanisms to regulate the pH of blood and maintain acid-base balance. The respiratory system helps control blood pH through the elimination of carbon dioxide, while the kidneys play a vital role in regulating bicarbonate ions and hydrogen ions in the blood.

**Importance of Alkaline Blood:**

Maintaining an alkaline pH is essential for optimal physiological functioning. Acidic blood can disrupt various bodily processes and lead to health issues such as acidosis. Alkaline blood helps support proper enzyme activity, cellular metabolism, oxygen transport, and overall body homeostasis.

In conclusion, blood is alkaline with a pH range of 7.35 to 7.45, primarily due to the buffering system and the presence of bicarbonate ions. This alkaline pH is crucial for sustaining the numerous biochemical reactions and maintaining the overall health of the body.