Cell Membranes and Transport: Before the Bell Biology

From a channel Lumen includes in full: The Amoeba Sisters (two biology teachers) make short animated lessons on cell biology, genetics, ecology and evolution that follow the standard high-school and intro-college biology syllabus.

A 7-minute video from Amoeba Sisters's catalogue; the title names its topic.

Video by Amoeba Sisters, played through YouTube's embedded player.