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.
Adair County Iowa. History. Summit Township. This subdivision of Adair county lies in the extreme northwestern corner of the same, and embraces all of congressional township 77 north, range 33 west. It is bounded on the north by Guthrie county, on the west by Cass county, on the east by Walnut township and on the south by Eureka township.