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There are two types of active transport: primary active transport that uses adenosine triphosphate (ATP), and secondary active transport that uses an electrochemical gradient. This process is in contrast to passive transport , which allows molecules or ions to move down their concentration gradient, from an area of high concentration to an area ...
Other factors may also dissipate the proton gradient creating an apparently leaky mitochondria. An uncoupling protein known as thermogenin is expressed in some cell types and is a channel that can transport protons. When this protein is active in the inner membrane it short circuits the coupling between the electron transport chain and ATP ...
Bioenergetics is a field in biochemistry and cell biology that concerns energy flow through living systems. [1] This is an active area of biological research that includes the study of the transformation of energy in living organisms and the study of thousands of different cellular processes such as cellular respiration and the many other metabolic and enzymatic processes that lead to ...
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).
The rate of ion transport through the channel is very high (often 10 6 ions per second or greater). Ions pass through channels down their electrochemical gradient , which is a function of ion concentration and membrane potential, "downhill", without the input (or help) of metabolic energy (e.g. ATP , co-transport mechanisms, or active transport ...
They are responsible for the active transport of calcium out of the cell for the maintenance of the steep Ca 2+ electrochemical gradient across the cell membrane. Calcium pumps play a crucial role in proper cell signalling by keeping the intracellular calcium concentration roughly 10,000 times lower than the extracellular concentration. [ 1 ]
Selective reabsorption is the process whereby certain molecules (e.g. ions, glucose and amino acids), after being filtered out of the capillaries along with nitrogenous waste products (i.e. urea) and water in the glomerulus, are reabsorbed from the filtrate as they pass through the nephron. [1]
Active BBC Bitesize , [ 1 ] also abbreviated to Bitesize , is the BBC 's free online study support resource for school-age pupils in the United Kingdom . It is designed to aid pupils in both schoolwork and, for older pupils, exams .