Cell Border Force


All life can be reduced to small units called cells. Some organisms like bacteria may only exist as a single cell, whereas many cells can work together to build complex organisms like humans. A cell is surrounded by a membrane that keeps all its contents together. Just like a border force agency at an airport, the cell must regulate what crosses this barrier in order to control its internal environment. Without this control, the chemical and biological processes going on in the cell would be severely disrupted and the cell would die. Various proteins perform these functions within the membrane and much research is directed toward understanding how they work. Researchers hope to be able to manipulate these types of proteins to create better medicines for combating disease.


The following challenge will introduce you to the kind of events occurring at the cell membrane, including signalling, ion exchange and protein translocation. Simply follow the instructions as they are displayed. All the processes involve different types of membrane proteins and you will be able to select the correct one(s) for the job. You may also have to describe the order of events by picking from multiple options. The correct answers will often be followed by an animation to illustrate what is happening at the molecular level. Good luck!

Further Reading

As you have seen, there are many processes that involve the cell membrane with different proteins performing specific functions. Signalling across the membrane allows the cell to detect changes in the external environment or respond to messages from the brain. Ion exchange enables the cell to maintain the optimum internal environment to carry out biochemical processes and the ability to transport proteins across membranes is important for secretion of vital hormones, enzymes and antibodies into the bloodstream. Understanding how cell membranes regulate these processes is fundamental to biology and medicine.

The biochemical society has excellent interactive websites for learning more about biology and biochemistry, including scibermonkey,  sciberbrain  and biochem4schools.

A fascinating visualization of the types of processes going on in cells is available here . 

Nick Johnson, who developed this activity studied at the University of Manchester. Here he talks more about his experiences.

For further information about studying Biochemistry at Manchester University, you can visit the department's webpage.

See what our current students have to say about studying Chemistry, and what research is being done by our lecturers.

You might also want to have a look at the Biology pages too.

Bright Knowledge (part of the Brightside Trust) has key information about studying for, and making a career in, Chemistry, Biology, and Medicine and Healthcare