Why do cells need ATP?

One of the ways in which ATP is used in the cell is to transport vesicles from the Golgi apparatus to different parts of the cells.

Vesicles act like postmen, carrying tagged proteins and lipids from the sorting office (Golgi) to the delivery address (around the cell).

The postvan is a tiny motor protein called kinesin carries the vesicle along pathways called microtubules.

Look at the video below to see how kinesin ‘walks’ along this pathway – doesn’t it resemble a human walking with a load on their head?

This walking movement is what uses ATP – every time the kinesin lifts a ‘foot’and places it forward, it hydrolyses a molecule of ATP, releasing energy which is used to place the ‘foot’ forward and down.

The vesicle that the kinesin carries can be much larger than its own size – much like how ants manage to carry cargo many times their size from one place to another.