Q1. Human babies and hibernating or cold-adapted animals are able to maintain body temperature (a process called thermogenesis) due to the presence of brown fat. Brown fat has a high concentration of mitochondria. The mitochondria in them have a protein called thermogenin, which allows the flow of hydrogen ions through an inner mitochondrial membrane (bypassing the ATP synthase). Based on this and your understanding of cellular respiration, propose a mechanism by which brown fat helps keep animals warm.

Q2. Animal cells are permeable to water and urea but NOT to sucrose. At first, inside of a cell contains 1 M sucrose and 1 M urea and the outside 1 M sucrose and 2 M urea. After system reaches equilibrium, what changes are observed?