The hydrolysis of ATP actually refers to the hydrolysis of high-energy phosphate bonds in ATP molecules.The hydrolysis of high-energy phosphoric acid bond can release a large amount of energychemical energyIt's stored in high-energy phosphate bonds.
Some ATPases areIntrinsic membrane protein, can be anchored atBiomembraneAnd can move on the membrane;These ATPases are also called transmembrane ATPases.
reaction mechanism
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ATPase
ATPase andATP hydrolysisReaction coupled transport is a strict chemical reaction, that is, the hydrolysis of each molecule of ATP can transport a certain number of solution molecules.For example, forSodium potassium ATPase, ATP hydrolysis per molecule can make 3Sodium ionTransported out of cells, two at the same timePotassium ionIs shipped in.
Transmembrane ATPases need the energy generated by ATP hydrolysis because these enzymes need to do work:thermodynamicsIn other words, with the membrane as the reference, they can transport substances from the low concentration side to the high concentration side.This process is calledActive transportation。
The basic assumption of the chemical permeation hypothesis is that when the high-energy electronsrespiratory chainDuring transmission, the released energy makes the proton (H+）Pump from the matrix side of mitochondrial inner membrane toMembrane gap；Intimal formationelectrochemistryProton gradient.There is energy in the gradientATP synthaseCatalyze and drive ADP and inorganic phosphoric acid to form ATP, namelyOxidative phosphorylationProcess.The basis of this hypothesismitochondrionThere are four specific assumptions about the function of:
2. MitochondriaATP synthasecomplexOrTransmembrane transportProton, but its action is reversible.The complex uses sufficient electrochemical proton gradient energy to synthesize ATP in its interior, when the protonMembrane gapFlowing towards the matrix through the complex;When the electrochemical proton gradient is insufficient to synthesize ATP, the ATPase complex can hydrolyze ATP, and the energy generated will pump protons from the matrix side to the membrane gap.
ATPase
3. The inner membrane of mitochondria generally does not allow ions to penetrate, especially H+、OH-Not free and transparent.
The transmembrane ATPase can import many substances needed for metabolism and export toxins, metabolic wastes and other substances that may hinder the cell process.For example,Sodium potassium ATPase(also called sodium/Potassium ionATPase) can regulate the concentration of sodium/potassium ions in cells, so as to maintain theResting potential；Hydrogen potassium ATPase (also known as hydrogen/potassium ion ATPase or stomachproton pump）It can keep acidified environment in stomach.
Except asIon exchangerThere are other categories of transmembrane ATPases, includingTransporter(co transporter) and "pump" (some "ion exchangers" are also called "pumps").Some of these transmembrane ATPases can cause the flow of charges inside and outside the membrane, while others cannot. Therefore, these transporters can be classified into the electrogenic type（electrogenic）And non electrified.
physiological function
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The body's stored ATP energy can only last for 15 seconds. After running 100 meters, it will be used up. If it is insufficient, it will continue to passRespirationAnd other synthetic ATP.Pure ATP is white powder and soluble in water. As a medicine, it can provide energy and improve the metabolism of patients.ATP tablet can be taken orally, and injection can provideintramuscular injectionorintravenous injection。
Strenuous exerciseWhen the body is in a temporary anoxic state, the metabolic process of energy substances in the body under anoxic state is called anaerobic metabolism.It includes the following twoEnergy supplySystem.
① Notlactic acidEnergy (ATP-CP) system can generally maintain anaerobic metabolism of muscle activity for 10 seconds.
② Lactic acid energy system - the non lactic acid energy (ATP-CP) system and lactic acid energy system that can generally maintain 1-3 points of muscle activity are the main ways of energy supply for muscles engaged in short-term and intense exercise.ATPRelease energyForMuscle contractionThe time of ATP synthesis is only 1-3 seconds, which depends on CP decomposition to provide energy, but the content of CP in muscle can only provide the energy decomposed after ATP synthesis to maintain 6-8 seconds of muscle contraction.Therefore, rapid activity within 10 seconds mainly depends on the ATP CP system to supply energy for muscle contraction.The lactic acid energy system is a kind of muscleMuscle glycogenEnzymolysis under anoxic condition, after a series ofchemical reactionFinally, lactic acid is produced in the body and energy is released for muscle contraction.This metabolic process can provide about 1-3 minutes for muscle contraction.
1. Understand the truth of sports promoting physical health
Sports can accelerate the consumption of energy and substances in the body, promote the decomposition and synthesis of substances in the bodyHistiocyteGet more nutrition than the original level,OrganismGet more vigorous activity ability, so that the body can continue to develop and improve, which is the basic principle of physical exercise to promote the healthy development of the body.
2. Understand energy supply and improvementAthletic abilityRelationship of
Sports consume energy substances in the body. After a period of rest, the energy substances in the body can recover or even exceed the original level. This change is calledExcess recovery。The degree and time of excessive recovery depend onAmount of exerciseSize of.The greater the amount of exercise in a certain range, the more energy in the bodyMaterial consumptionThe more you have, the greater the extent of over recovery is, but the time required is also long. In the stage of over recovery of the body, the second appropriate exercise and rest can gradually improve the level of energy supply of the human body, so as to continuously improve the human movement ability.
Anaerobic metabolic capacity isSpeed qualityThe important foundation of.PEclassThe method of developing anaerobic metabolic capacity is generally intermittent exercise andSustainabilitypractice.Intermittent exercises mainly develop the energy supply capacity of the ATP CP system.Generally, each practice is within 30 seconds, and 1-3 minutesActive rest, and then appropriate exercises can improve the speed quality.Continuous practice mainly develops the supply capacity of lactic acid system.Generally, each exercise lasts more than 30 secondsrest timeShort, can improve speed endurance.
Aerobic metabolism is a long-term processAerobic exerciseAbility.The key to the development of aerobic metabolic capacity is to have sufficient oxygen supply, that is, human unit timeInternal absorptionMaximum value of oxygen utilization——Maximum oxygen consumption。The maximal oxygen consumption is closely related to the oxygen carried and transported by blood circulation in unit time.Therefore,Cardiopulmonary functionThe quality of will directly affect the maximum oxygen consumption.Use low or mediumExercise intensityThe exercise lasts for a long time. Since the body can get sufficient oxygen supplyAerobic oxidationEnergy supply, therefore, can improve aerobic metabolism, thereby improving cardiopulmonary function.
In addition to the above side effects, ATP can also causeAnaphylactic shock。In recent years, cases of anaphylactic shock and even death caused by ATP have been reported from time to time in China.hisclinical manifestationFor trembling, fidgetingdyspneaandArrhythmiaTherefore, attention should be paid to the following issues when using:
(2) After ATP is decomposed in the body, it can make the whole bodyVasodilation, blood pressure drops, so it is not suitable foracute myocardial infarction 。cerebral hemorrhageATP shall also be disabled at the initial stage.ATP should not be combined with drugs that can aggravate negative conduction and frequency effects.
(3) The intravenous injection should be slow, and the treatment should start from a small dose. If it is ineffective, the dosage can be gradually increased.
ATP synthase canProton dynamic potentialPromoted by, use ADP and Pi to catalyze the synthesis of biological energy“currency”——ATP。In general, most of the ATP needed by the body isATP SynthaseGenerated.It is estimated that the amount of ATP needed by the human body for normal activities every dayApproximately equal toHis weight, such as that of an adult weighing 70kg, is synthesized every day for normal useLife activitiesThe amount of ATP is about 70kg.Such a huge amount of ATP is synthesized by countless ATP synthase in the human body.
At the same time,ATP synthaseIt can also catalyzeReverse reactionThat is ATP hydrolysis.Therefore, in a sense, ATP synthase is also a kind of ATPase.
