Biological Buffer Systems

Front

Almost every biological process is pH-dependent; a small change in pH produces a large change in the rate of the process.

Back

What is the significance of pH in biological processes?

Front

Enzymes and many of their substrates contain ionizable groups with characteristic pKa values.

Back

What role do ionizable groups play in enzymes and substrates?

Front

Cells maintain a specific and constant cytosolic pH, usually near pH 7, keeping biomolecules in their optimal ionic state.

Back

How do cells maintain cytosolic pH?

Front

Constancy of pH is achieved primarily by biological buffers.

Back

What is the primary means of achieving pH constancy in biological systems?

Front

The ion product of water (Kw) is derived from the equilibrium constant (K_eq) and describes the ionization of pure water.

Back

What is the ion product of water (Kw)?

Front

It relates to the dissociation of weak acids in equilibrium and helps calculate pH based on the ratio of proton acceptor to proton donor.

Back

What is the Henderson-Hasselbalch equation used for?

Front

A titration curve is the plot of the pH of the analyte solution vs. the volume of the titrant added as the titration progresses.

Back

What does a titration curve represent?

Front

The bicarbonate buffer system, consisting of H2CO3 (proton donor) and HCO3- (proton acceptor).

Back

What is the principal buffer in blood plasma?

Front

Acidosis is the accumulation of acids or loss of alkali, leading to a fall in the bicarbonate concentration.

Back

What is acidosis?

Front

1. Metabolic acidosis: due to excessive loss of bases. 2. Respiratory acidosis: due to retention of CO2.

Back

What are the two types of acidosis?