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.
CELEBRATE NATIONAL. POETRY MONTH Discover a wide variety of poets and poems from the Akron-Summit County Public Library collection during this literary celebration. AUTHOR! AUTHOR! @ YOUR LIBRARY Meet the authors and learn about the worlds of writing and publishing at these upcoming Library programs. BEGINNING. BEEKEEPING Aspiring beekeepers, get the information you need to get started at these upcoming Library programs.