Atelopus petersi Atelopus petersi Atelopus petersi is a species of toads in the family Bufonidae. It is endemic to Ecuador and is known from the Cordillera Oriental in the Napo Province and more provisionally, in the Chimborazo Province. The specific name "petersi" honors James A. Peters, an American zoologist who collected the first specimens of this species in 1962 and provided a description under the name "Atelopus pachydermus". Common names Peters' stubfoot toad and Peters' jambato toad have been coined for it. Adult males measure and adult females in snout–vent length. The snout is acuminate. The tympanic membrane, annulus, and stapes are
Cell membrane concentration in order to equilibrate the membrane. It is considered a passive transport process because it does not require energy and is propelled by the concentration gradient created by each side of the membrane. Such a concentration gradient across a semipermeable membrane sets up an osmotic flow for the water. Osmosis, in biological systems involves a solvent, moving through a semipermeable membrane similarly to passive diffusion as the solvent still moves with the concentration gradient and requires no energy. While water is the most common solvent in cell, it can also be other liquids as well as supercritical liquids and