Final answer:
The three chemical molecules which are excellent buffers in the bloodstream include the bicarbonate buffer system, phosphate buffer system, and protein buffers such as albumin and hemoglobin.
Step-by-step explanation:
The three chemical molecules found in the bloodstream that are excellent buffers and were likely discussed in today's lab include the bicarbonate buffer system, phosphate buffer system, and protein buffers.
Bicarbonate Buffer System
The bicarbonate buffer consists of a mixture of carbonic acid (H₂CO₃) and bicarbonate (HCO₃). This buffer plays a significant role in maintaining the pH of blood and extracellular fluid, mainly by reacting with hydrogen ions to reduce major shifts in pH.
Phosphate Buffer System
Inside many of the body's cells, a buffer system based on phosphate ions is at work. The phosphate buffer system helps to stabilize pH within cells and complements the overall buffering capacity of bodily fluids.
Protein Buffers
Almost all proteins, including albumin and hemoglobin, have the ability to function as buffers. Proteins contain amino groups and carboxyl groups that can bind hydrogen and hydroxyl ions, contributing substantially to the buffering power of both blood and cellular fluids. Hemoglobin is particularly important as it constitutes a significant portion of red blood cells and offers one-third of the buffering capacity in blood.