Why do cells need ATP?
ATP is the energy currency of the cell. During the process of respiration, cells turn glucose into a valuable chemical currency – ATP. ATP is needed to drive a variety of metabolic reactions in the cell. This includes cell division, cell growth, all enzyme activity, movement of vesicles around and outside the cell including exocytosis and processes like respiration, fatty acid metabolism and apoptosis.
Some of the process are listed below. Hopefully by the end of this article, you will have a much better idea of why ATP is so valuable to the cell.
Role of ATP in Cell Division
During the life cycle of a cell, each cell divides to form two genetically identical cells. This process is called mitosis.
Before the cell enters mitosis, the DNA duplicates. During the process of mitosis each half of the DNA is pulled to towards the opposite poles of the cell. When the cell divides into two, each new daughter cells receives one copy of the full DNA complement, identical to the parent.
This process is controlled by spindle fibres. Spindle fibres pull each half of the duplicated DNA to opposite poles of the cell.
Spindle fibres are made of a protein called tubulin. The length of spindle fibres can be changed by adding or removing tubulin. Addition of tubulin proteins causes the spindle fibres to elongate (polymerisation), and removal of the proteins causes the spindle fibres to shorten (depolymerisation).
During spindle fibre contraction, the process of depolymerisation causes spindle fibres to shorten. Depolymerisation uses energy in the form of GTP and ATP. When the spindle fibres depolymerise, a force is generated. The force causes the chromosomes to be pulled to the opposite poles of the cell. A motor protein called kinesin is also believed to be involved in the movement.
Have a look at the video below to get a better understanding of the process: