Moving on to the fourth basic property of cells, as outlined by Karp:
Just like every life form on the planet Earth, cells require the input of energy to carry out biological processes. Electromagnetic radiation from the sun is what provides energy to all of the life forms on the planet. Light-absorbing pigments present in the membranes of photosynthetic cells trap the energy of light. The process of photosynthesis then converts this light energy into chemical energy. This chemical energy is stored in energy-rich carbohydrates, including sucrose and starch, for example. Energy can be prepared beforehand in the form of sugar glucose, which is the case for most animal cells. In the case of humans, the liver releases glucose into the blood. As this glucose circulates throughout the body, chemical energy is delivered to all of the cells. Glucose, after it is inside a cell, is then “broken down” in a way that allows its energy content to be stored in a form that is readily-available. One of the ways in which this energy is stored is as ATP. Later on, this ATP is put to use in providing the energy required to carry out many of the cell’s activities. When cells break down and rebuild the macromolecules from which they are made, a lot of energy is required. This is known as a continual “turnover,” which provides a few benefits to the cell. Among these are maintaining the integrity of the different cell components throughout the inevitable wear and tear that the cell undergoes, which helps the cell then to provide a quick response to evolving conditions (Karp 2013).
A prospective medical student, looking to help others succeed.