Proton Gradient
Proton Gradient - Related Videos
09:40
Proton Exchange Membrane Fuel Cells
0 Views •
2023
Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University The United States consumes a large amount of energy – the current rate is around 97.5 quadrillion BTUs annually. The vast majority (90%) of this energy comes from non-renewable fuel sources. This energy is used for electricity (39%), transportation (28%), industry (22%), and residential/commercial use (11%). As the world has a limited supply of these non-renewable sources, the United States (among others) is...
08:42
Density Gradient Ultracentrifugation
0 Views •
2023
Density gradient ultracentrifugation is a common technique used to isolate and purify biomolecules and cell structures. This technique exploits the fact that, in suspension, particles that are more dense than the solvent will sediment, while those that are less dense will float. A high-speed ultracentrifuge is used to accelerate this process in order to separate biomolecules within a density gradient, which can be established by layering liquids of decreasing density in a centrifuge tube. The...
10:10
Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
0 Views •
Cited by 11 •
2016
The motion regimes of ibuprofen encapsulated in β-cyclodextrin nanosponges polymer network are investigated using pulsed-field-gradient spin-echo (PGSE) NMR technique. Synthesis, purification, drug loading, implementation of the NMR pulse sequence and data analysis to work out the mean square displacement of the drug at several observation times are described in detail.
03:36
Purification of Bacteriophages Using a Sucrose Density Gradient
0 Views •
2026
Source: Rustad, M., et.al. Synthesis of Infectious Bacteriophages in an E. coli-based Cell-free Expression System. J. Vis. Exp. (2017)This video demonstrates the purification of bacteriophages from a suspension containing host bacterial debris using a sucrose density gradient. It shows how the density gradient separates phages by buoyant density, enabling recovery of a visible band for resuspension and further analysis.
10:52
Denaturing Gradient Gel Electrophoresis (DGGE)
0 Views •
Cited by 10 •
2007
FAQs
Its energy has two linked components: a difference in hydrogen ion concentration and a difference in electrical charge across the membrane. Together, these properties create the proton-motive force, rather than relying on concentration alone. This combined electrochemical energy explains why the gradient can drive several cellular processes, not only ATP production.
ATP synthase provides a controlled route for protons to return across the membrane. Their movement through the enzyme supplies energy that drives the formation of ATP from ADP and phosphate. In this way, the enzyme couples an ion-flow event to chemical energy storage, linking membrane bioenergetics directly to the cell’s ATP supply.
The membrane location differs between major energy-converting organelles. In cellular respiration, the mitochondrial inner membrane maintains the relevant gradient, whereas photosynthetic light-driven reactions generate one across chloroplast membranes. This distinction connects the same energy-storage principle to two different biological inputs: electron transport during respiration and light-driven reactions during photosynthesis.
Separation across a membrane is essential because it stores energy in an organized electrochemical difference. Electron transport chains or light-driven reactions move protons to one side, and the resulting proton-motive force makes their return energetically useful. ATP synthase can then capture that directed flow instead of allowing the energy difference to remain unused.
Beyond ATP synthesis, proton flow can power membrane transport and flagellar movement. The gradient therefore functions as a versatile energy source for work at the membrane and for cellular movement. In bacteria, it also contributes to energy conservation, showing that its role extends beyond the organelles associated with respiration and photosynthesis.
The gradient serves as an intermediate energy store between proton-moving reactions and ATP formation. Electron transport chains establish it during cellular respiration, while ATP synthase uses its return flow to produce ATP. This arrangement links membrane electron-transfer activity with the chemical energy that cells can use for metabolic work.