A cell is the basic building block for all living organisms. It is considered the smallest unit of a living entity and can create a unicellular life form (e.g. bacteria) or more complicated life (e.g. a human being.) Cells are split into two categories: prokaryotic and eukaryotic. Cells have a basic design that includes a membrane that gives the cell structure, a nucleus that provides central location for DNA and cytoplasm, which is the liquid environment of the cell itself. Cells grow, die and metabolize food particles for energy, functions and division.
Purpose of Cellular Respiration
Cell respiration is one of the ways a cell obtains energy. It is a function of a cell’s metabolism. Cellular respiration turns food particles into water and carbon dioxide. A certain amount of energy is released during the process that the cell uses for its activities. Cellular respiration is broken down into two phases–glycoslysis and oxidation. In glycolysis, the cell breaks down the food molecule glucose into pyruvic acid. The process occurs without need of oxygen for the reaction and it is the first step in the aerobic and anaerobic energy-gathering reaction. It occurs in the cytoplasm (the fluid environment of the cell) and is the metabolic function all organisms share.
While glycosis takes place in the cytoplasm of the cell, part of the process also occurs in the mitochondria. Mitochondria are specialized portions of a cell that are dedicated to energy conversion of adenosine triphosphate, or ATP, from food. Mitochondria supply energy for cellular functions, including cell specialization, cellular communication, growth, cell death and cellular division.
In oxidation, the pyruvic acid is converted into water and carbon dioxide. Pyruvic acid creates NADH from its own molecules as it is oxidized. NADH is a coenzyme also known as nicotinamide adenine dinucleotide, also used by cells for processes.
ATP is is a molecule that cells use for the storage and transportation of energy. ATP is formed as food that is broken down on the molecular level. An ATP molecule is composed of several phosphates. As the phosphate breaks down, energy is released for endergonic reactions. ATP also is a molecule used for cell signaling, the process in which cells transmit information.