Problem 4

Background and context

Proteins called uniporters, symporters, and antiporters are involved in the transport of chemicals through cell membranes.

Uniporters help with facilitated diffusion by attaching to one molecule of substrate at a time and moving it down a concentration gradient. Active transport involves symporters and antiporters. Antiporters move molecules in the opposite direction, whereas symporters move them in the same way.