Buffer systems in the body maintain proper pH balance in order for life processes to proceed. Proteins found in the blood plasma are often used as buffers. What makes a protein able to function as a buffer? The protein’s molecular shape must enable it to bind with other proteins in the plasma. The protein must be capable of both accepting and releasing protons. The protein must maintain its ability to release various amino acids, thus changing its molecular shape. The protein must take on a conformation change according to the activity of the associated enzyme in regulating the blood’s pH.

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.