Figure 1. Types of movement across membranes. Molecules can diffuse across a. membrane down a concentration gradient without the aid of a protein or the input of. energy. Passive and active transport require membrane transport proteins. Channel. proteins carry out passive transport, but carrier proteins can carry out passive or active. transport.
Akron, Iowa. Akron is a city in Plymouth County, Iowa, United States. The population was 1,486 at the 2010 census.
Summit County is an urban county in the U.S. state of Ohio. As of the 2010 census, the population was 541,781 making it the fourth-most populous county in Ohio. Its county seat is Akron. The county was formed on March 3, 1840, from portions of Medina, Portage and Stark Counties.