Question

One of the buffers that contribute to pH stability in human blood is cabonic acid (H2CO3) Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HC03- and a hydrogen ion (H+) Thus H2CO3 arrows HCO3- +Hpos . If the pH of the blood increase, one would expect

Answer 1

Buffer systems in human blood, such as the carbonic acid-bicarbonate buffer system, help maintain a near-neutral pH by converting excess bicarbonate ions to carbonic acid. This process removes hydrogen ions and moderates pH changes. Buffer systems are crucial for maintaining a stable pH in the body.

Step-by-step explanation:

Buffer systems in human blood help maintain a near-neutral pH, even when ingesting acidic or basic substances. One important buffer is the carbonic acid-bicarbonate buffer system, which involves the conversion of bicarbonate ions to carbonic acid to remove excess hydrogen ions and moderate pH changes.

For example, when the pH of blood increases, the buffer system shifts to convert excess bicarbonate ions to carbonic acid. This helps remove hydrogen ions and prevent a significant increase in blood pH. In addition, excess carbonic acid can be converted to carbon dioxide gas and exhaled through the lungs to further regulate pH.

Without the presence of buffer systems, the body's pH would fluctuate and survival could be endangered. Buffers are essential for maintaining a stable pH in the body and ensuring proper bodily functions.

Answer 2

If the pH of the blood increases, one would expect a shift in the carbonic acid (H₂CO₃) equilibrium towards the production of more hydrogen ions (H+) and bicarbonate ions (HCO₃-). This shift helps maintain pH stability through the buffering capacity of the carbonic acid/bicarbonate system.

Step-by-step explanation:

In the carbonic acid (H₂CO₃) equilibrium, the reaction can be represented as:

`[H_2CO_3 rightleftharpoons HCO_3⁻ + H⁺]`

When the pH of the blood increases, indicating a shift towards a more basic or alkaline environment, the equilibrium of the carbonic acid reaction will move to the left. This means that carbonic acid will dissociate into more hydrogen ions (H+) and bicarbonate ions (HCO₃-), counteracting the increase in pH. This shift is part of the body's natural buffering system, which helps maintain blood pH within a narrow range for proper physiological function.

The equation shows that when carbonic acid dissociates, it releases hydrogen ions and forms bicarbonate ions. By doing so, it consumes excess hydroxide ions ((OH⁻)) that may be contributing to the increased pH, bringing the blood back to a more stable acidic state. This dynamic equilibrium ensures that the blood pH remains within the normal physiological range, as deviations from this range can have detrimental effects on enzymatic activity and overall cellular function.

In summary, the shift in the carbonic acid equilibrium towards the production of more hydrogen ions and bicarbonate ions acts as a buffer, helping to counteract and stabilize the pH when it increases. This process is a crucial component of the body's acid-base homeostasis.