Learn to Predict

From page 58

Answer

mutation in the membrane receptor gene specific for ADH can,therefore, disrupt ADH regulation, since the kidney cells cannotrespond to ADH. On the other hand, aquaporins are membraneproteins that regulate osmosis or diffusion of water across themembrane. A mutation in an aquaporin gene can also lead tothe disruption of water homeostasis.

Answers to the rest of this chapter’s Predict questions are inappendix G.

Consider first the important points made in the question itself.First, Carlos suffers from a genetic disease (diabetes insipidus)and, second, this disease results in excessive water loss at thekidneys. In this chapter, we learned that genes determine thestructure of cellular proteins. But the question is, what type ofprotein? There are two possibilities. We also learned that cellu-lar proteins have many functions, including membrane recep-tors and transport proteins. Mutations in the gene for either typecan lead to disruption in water homeostasis. ADH is a hormone,or chemical signal, that regulates water loss from the kidneys. A