What type of protein controls what goes in and out of cells

In simple diffusion, small molecules without charges such as oxygen and carbon dioxide flow through a plasma membrane without assistance and without expending energy. Other substances such as proteins, glucose and charged particles called ions cannot pass through the selectively permeable membrane.

I'm into politics, why am i getting these questions? it's 4: 30 am in texas. my paper is due in 2 days. i'm the one needing in political science

U whay do you need with?