BPK 105 Study Guide - Final Guide: Carbonic Anhydrase, Phosphate
27 Apr 2018
School
Department
Course
Professor
Module 12 - Review Questions - Part 6
9. Draw the series of reversible reactions catalyzed by the enzyme carbonic anhydrase,
including the names and formulae of the components involved. Describe the
compensation that would occur, within this buffer system, if there was an sudden
increase in carbon dioxide dissolved in the blood. [5 marks]
- Buffers are chemicals that resist a change in the pH of a solution when either acids or
bases are added to the solution.
- The buffers in the body fluids contain salts of either weak acids or weak bases that
combine with H+ when H+ increases in those fluids, or release H+ when H+ decreases
in those fluids.
- Buffers tend to keep the H+ concentration, and thus the pH, within a narrow range of
values (figure 18.22) because of these characteristics. The three major buffers in the
body fluids are the proteins, the PO43− buffer system, and the HCO3− buffer system.
- Proteins and PO43− in the body fluids are able to combine reversibly with hydrogen
ions.
- When the H+ concentration increases, proteins and PO43− prevent a decrease in pH by
combining with the hydrogen ions.
The following reaction illustrates how PO43− buffers work:
Monohydrogen phosphate ions (HPO42−) combine with H+ to form dihydrogen phosphate ions
(H2PO4−) when excess H+ is present. When H+ concentration declines, some of the H+
separate from the H2PO4−.
Proteins are able to function as buffers because their amino acids have side chains that function
as weak acids and weak bases. Many side chains contain carboxyl groups (–COOH) or amine
groups
(–NH2). Both of these groups are able to function as buffers because of the following
Document Summary
Module 12 - review questions - part 6: draw the series of reversible reactions catalyzed by the enzyme carbonic anhydrase, including the names and formulae of the components involved. Describe the compensation that would occur, within this buffer system, if there was an sudden increase in carbon dioxide dissolved in the blood. Buffers are chemicals that resist a change in the ph of a solution when either acids or bases are added to the solution. The buffers in the body fluids contain salts of either weak acids or weak bases that combine with h+ when h+ increases in those fluids, or release h+ when h+ decreases in those fluids. Buffers tend to keep the h+ concentration, and thus the ph, within a narrow range of values (figure 18. 22) because of these characteristics. The three major buffers in the body fluids are the proteins, the po43 buffer system, and the hco3 buffer system.
