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.
Join John Philip Colletta, PhD., the Summit County Chapter of the Ohio Genealogical Society and more as we present a day of genealogy. The Akron-Summit County Public Library will begin offering online tutoring and career help from Tutor.com starting this September.