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Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate (ATP), and secondary active transport that uses an electrochemical gradient.
The sodium–potassium pump (a type of P-type ATPase) is found in many cell (plasma) membranes and is an example of primary active transport.Powered by ATP, the pump moves sodium and potassium ions in opposite directions, each against its concentration gradient.
Including one H + for the transport reactions, this means that synthesis of one ATP requires 1 + 10/3 = 4.33 protons in yeast and 1 + 8/3 = 3.67 in vertebrates. This would imply that in human mitochondria the 10 protons from oxidizing NADH would produce 2.72 ATP (instead of 2.5) and the 6 protons from oxidizing succinate or ubiquinol would ...
Unlike diffusion (a form of passive transport), solute pumping requires energy (provided by ATP) to change the shape of the protein channel to allow the molecule to pass through, which is why it is an active transport mechanism.
The enzymatic hydrolysis of ATP requires proper binding of the phosphates and positioning of the γ-phosphate to the attacking water. [23] In the nucleotide binding site, the oxygen atoms of the β- and γ-phosphates of ATP are stabilized by residues in the Walker A motif [49] [50] and coordinate with Mg 2+. [23]
Therefore, making and exporting one ATP requires 4H +. The inner membrane contains an antiporter , the ADP/ATP translocase, which is an integral membrane protein used to exchange newly synthesized ATP in the matrix for ADP in the intermembrane space.
In active transport a solute is moved against a concentration or electrochemical gradient; in doing so the transport proteins involved consume metabolic energy, usually ATP. In primary active transport the hydrolysis of the energy provider (e.g. ATP) takes place directly in order to transport the solute in question, for instance, when the ...
Secondary active transport is when one solute moves down the electrochemical gradient to produce enough energy to force the transport of another solute from low concentration to high concentration. [ citation needed ] An example of where this occurs is in the movement of glucose within the proximal convoluted tubule (PCT).