Respiration occurs in the mitochondriaof the cells in all organisms, all the time.
Respiration is the process by which the cell breaks down glucose to produce ATP - Adenosine triphosphate.
Cellular Respiration
ATP is the ‘energy’ molecule that is used to fuel all the chemical reactions of the cell, including:
Active transport of substances across membranes
Synthesis of molecules
Movement, e.g. phagocytosis, action of actin and myosin in muscle contraction
Bioluminescence in cells of such animals as glow-worms and fireflies.
Cellular Respiration
word equation: glucose + oxygen → carbon dioxide + water + ATP + heat energy
Cellular Respiration - Producing Energy
The breakdown of glucose may be anaerobic (no oxygen present) or aerobic (oxygen present).
ATP is constantly made in cells from ADP - adenosine diphosphate. The energy from respiration adds a high-energy phosphate bond to ADP, making it an ATP molecule.
Factors Affecting the Rate of Cellular Respiration
The rate of respiration is determined by factors such as temperature and energy demands.
Factors Affecting the Rate of Respiration
Temperature - Increasing the temperature increases the rate of respiration to a certain point (optimum temperature). If temperatures rise too much above the optimum temperature, the enzymes controlling the reaction denature and the reaction no longer takes place.
Factors Affecting the Rate of Cellular Respiration
Energy demands - The rate of respiration will increase to a maximum rate as the energy demand from the cells of tissues increases. For examples, muscle cells of legs when a human sprints.
As the amount of O2 needed and CO2 produced increases, the breathing rate increases to compensate.