Examples of concentration gradient in the following topics:
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- In secondary active transport, a molecule is moved down its electrochemical gradient as another is moved up its concentration gradient.
- Instead, another molecule is moved up its concentration gradient, which generates an electrochemical gradient.
- The molecule of interest is then transported down the electrochemical gradient.
- As sodium ion concentrations build outside the plasma membrane because of the action of the primary active transport process, an electrochemical gradient is created.
- An electrochemical gradient, created by primary active transport, can move other substances against their concentration gradients, a process called co-transport or secondary active transport.
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- On the contrary, concentration gradients are a form of potential energy, dissipated as the gradient is eliminated.
- Each separate substance in a medium, such as the extracellular fluid, has its own concentration gradient independent of the concentration gradients of other materials.
- This lack of a concentration gradient in which there is no net movement of a substance is known as dynamic equilibrium.
- Extent of the concentration gradient: The greater the difference in concentration, the more rapid the diffusion.
- Diffusion through a permeable membrane moves a substance from an area of high concentration (extracellular fluid, in this case) down its concentration gradient (into the cytoplasm).
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- Osmosis is the movement of water through a semipermeable membrane according to the concentration gradient of water across the membrane, which is inversely proportional to the concentration of solutes.
- Water has a concentration gradient in this system.
- Thus, water will diffuse down its concentration gradient, crossing the membrane to the side where it is less concentrated.
- This diffusion of water through the membrane—osmosis—will continue until the concentration gradient of water goes to zero or until the hydrostatic pressure of the water balances the osmotic pressure.
- Describe the process of osmosis and explain how concentration gradient affects osmosis
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- In passive transport, substances move from an area of higher concentration to an area of lower concentration .
- A physical space in which there is a range of concentrations of a single substance is said to have a concentration gradient.
- In solutions containing more than one substance, each type of molecule diffuses according to its own concentration gradient, independent of the diffusion of other substances.
- Many factors can affect the rate of diffusion, including, but not limited to, concentration gradient, size of the particles that are diffusing, and temperature of the system.
- Diffusion through a permeable membrane moves a substance from an area of high concentration (extracellular fluid, in this case) down its concentration gradient (into the cytoplasm).
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- Simple concentration gradients are differential concentrations of a substance across a space or a membrane, but in living systems, gradients are more complex.
- The electrical gradient of K+, a positive ion, also tends to drive it into the cell, but the concentration gradient of K+ tends to drive K+ out of the cell.
- The combined gradient of concentration and electrical charge that affects an ion is called its electrochemical gradient .
- To move substances against a concentration or electrochemical gradient, the cell must use energy.
- Electrochemical gradients arise from the combined effects of concentration gradients and electrical gradients.
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- Osmotic pressure is influenced by the concentration of solutes in a solution.
- Water passes through semi-permeable membranes by passive diffusion, moving along a concentration gradient and equalizing the concentration on either side of the membrane.
- Active transport requires energy in the form of ATP conversion, carrier proteins, or pumps in order to move ions against the concentration gradient.
- Passive transport, such as diffusion, requires no energy as particles move along their gradient.
- Active transport requires additional energy as particles move against their gradient.
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- Diffusion arises from the statistical tendency of particles to redistribute from regions where they are highly concentrated to regions where the concentration is low .
- Differences in concentration of ions on opposite sides of a cellular membrane lead to a voltage called the membrane potential.
- Many ions have a concentration gradient across the membrane, including potassium (K+), which is at a high inside and a low concentration outside the membrane.
- Sodium (Na+) and chloride (Cl–) ions are at high concentrations in the extracellular region, and low concentrations in the intracellular regions.
- These concentration gradients provide the potential energy to drive the formation of the membrane potential.
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- Diffusion is the movement of particles from regions of high concentration towards regions of lower concentration.
- Diffusion is the movement of particles move from an area of high concentration to an area of low concentration until equilibrium is reached .
- Diffusion explains the net flux of molecules from a region of higher concentration to one of lower concentration.
- However, diffusion can still occur in the absence of a concentration gradient.
- Particles moving from areas of high concentration to areas of low concentration.
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- Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient.
- The uneven distribution of H+ ions across the membrane establishes both concentration and electrical gradients (thus, an electrochemical gradient) owing to the hydrogen ions' positive charge and their aggregation on one side of the membrane.
- This protein acts as a tiny generator turned by the force of the hydrogen ions diffusing through it, down their electrochemical gradient.
- In oxidative phosphorylation, the hydrogen ion gradient formed by the electron transport chain is used by ATP synthase to form ATP.
- ATP synthase is a complex, molecular machine that uses a proton (H+) gradient to form ATP from ADP and inorganic phosphate (Pi).
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- Anaerobic respiration utilizes highly reduced species - such as a proton gradient - to establish electrochemical membrane gradients.
- An electrochemical gradient has two components.
- Second, a chemical component is caused by a differential concentration of ions across the membrane.
- Cellular respiration (both aerobic and anaerobic) utilizes highly reduced species such as NADH and FADH2 to establish an electrochemical gradient (often a proton gradient) across a membrane, resulting in an electrical potential or ion concentration difference across the membrane.
- In contrast, fermentation does not utilize an electrochemical gradient.