Definition of ATP synthase
ATP synthase is an enzyme that directly generates adenosine triphosphate (ATP) during the process of cellular respiration. ATP is the main molecule energy molecule used in cells. ATP synthase forms ATP synthase from adenosine diphosphate (ADP) and an inorganic phosphate (P i ) through the oxidative phosphorylationwhich is a process in which enzymes oxidise nutrients to form ATP. ATP synthase is found in all forms of life and powers all cellular activities.
Function of ATP synthase
The function of ATP synthase is to produce ATP. ATP is needed to fuel all cellular processes, so it is constantly used by cells and must be constantly produced. Each ATP synthase can produce about 100 ATP molecules per second. The eukaryoteseukaryotes, such as plants, animals and fungihave organelles called mitochondria that function primarily as ATP producers. Plants also have chloroplasts that contain ATP synthase and can produce ATP from sunlight and carbon dioxide. carbon dioxide. Bacteria and archaea, which form the prokaryotes, do not have mitochondria but produce ATP through similar processes of cellular respiration in their plasma membrane. In all forms of life, ATP synthase has basically the same structure and function. It is therefore believed to have evolved early in the evolution of life and would have been found in the last common ancestor of all life on Earth.
Structure of ATP synthase
ATP Synthase has two parts. The part embedded within the membrane of the mitochondria (in eukaryotes), the thylakoid membrane of the mitochondria (in eukaryotes), the thylakoid membrane of the chloroplast (only in plants), or plasma membrane (in prokaryotes) is called F O. This is a motor that runs on H + flowing through the membrane. The part inside the mitochondrionthe stroma of the chloroplast or within the cell bacterial or archaeal cell is called F 1 -ATPase. This is another motor that is used to generate ATP. It is believed that these two parts were two separate structures with two different functions that eventually evolved into ATP synthase. The F OThe region is similar to the helicases from DNA (enzymes that decompress DNA so that it can be used as a template for replication), while the F 1 -ATPase is similar to the H + which allow flagella, arm-like appendages in some bacteria, to move. F 1 -ATPase has a central stalk and rotor which, when turned, converts ADP and P i in ATP.
This is an interpretation of the structure of ATP synthase. F O is shown in blue and violet, while F 1 -ATPase is shown in red.
ATP synthesis
ATP is produced through different methods: through cellular respiration in the mitochondria, during the photosynthesis in plant chloroplasts and through the inner membrane of bacteria and archaea, which do not have mitochondria. Although the methods of ATP production vary between different types of organisms, they all follow a similar basic procedure.
In the mitochondria of eukaryotes, the molecules NADH and FADH 2which are products of the citric acid cycle, pass electrons through a electron transport chainwhere they travel through three different protein complexes. This process releases energy, and this energy allows protons (H + ) travel down a proton gradient through protein complexes, which act as proton pumps. The flow of these protons down the gradient turns the rotor and stalk of ATP synthase, which makes possible a phosphate group.bond with adenosine diphosphate (ADP), forming ATP. In chloroplasts, the process is similar, except that light energy is the type of energy that excites electrons, causing them to flow down the electron transport chain and allow H + travel across a membrane in the chloroplast. These methods are similar in very different organisms, as the ability to generate ATP existed in the common ancestor of all living organisms.
- Adenosine triphosphate (ATP): the main energy molecule used by the cell.
- Eukaryotes: organisms that have eukaryotic cells, which are complex cells with a nucleus and organelles.
- Mitochondria: the organelle of eukaryotic cells that produces ATP.
- Chloroplast: the organelle of plant cells which, in addition to mitochondria, produces ATP through photosynthesis.