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.
Abbreviations or Slang with similar meaning. 1  AKO - Colorado Plains Regional Airport, Akron, Colorado, United States. 2  ALN - St. Louis Regional Airport, Alton, Illinois, United States. 3  APN - Alpena County Regional Airport, Alpena, Michigan, United States. 4  ATW - Outagamie County Regional Airport, Greenville, Wisconsin, United States.