Examples of free energy in the following topics:
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- Free energy, called Gibbs free energy (G), is usable energy or energy that is available to do work.
- A measurement of free energy is used to quantitate these energy transfers.
- Free energy is called Gibbs free energy (G) after Josiah Willard Gibbs, the scientist who developed the measurement.
- In other words, Gibbs free energy is usable energy or energy that is available to do work.
- A negative ∆G also means that the products of the reaction have less free energy than the reactants because they gave off some free energy during the reaction.
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- Since ATP hydrolysis releases energy, ATP synthesis must require an input of free energy.
- Exactly how much free energy (∆G) is released with the hydrolysis of ATP, and how is that free energy used to do cellular work?
- Unless quickly used to perform work, ATP spontaneously dissociates into ADP + Pi, and the free energy released during this process is lost as heat.
- The Na+/K+ pump gains the free energy and undergoes a conformational change, allowing it to release three Na+ to the outside of the cell.
- By donating free energy to the Na+/K+ pump, phosphorylation drives the endergonic reaction.
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- Activation energy is the energy required for a reaction to occur, and determines its rate.
- This small amount of energy input necessary for all chemical reactions to occur is called the activation energy (or free energy of activation) and is abbreviated EA.
- Since these are energy-storing bonds, they release energy when broken.
- The free energy released from the exergonic reaction is absorbed by the
endergonic reaction.
- Free energy diagrams illustrate the energy profiles for a given reaction.
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- A living cell cannot store significant amounts of free energy.
- Excess free energy would result in an increase of heat in the cell, which would lead to excessive thermal motion that could damage and then destroy the cell.
- ATP is often called the "energy currency" of the cell and can be used to fill any energy need of the cell.
- The hydrolysis of ATP produces ADP, together with an inorganic phosphate ion (Pi), and the release of free energy.
- The ADP molecule and a free phosphate ion are released into the medium and are available for recycling through cell metabolism.
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- Mitochondria are energy-producing organelles that are thought to have once been a type of free-living alpha-proteobacterium.
- Eukaryotic cells contain anywhere from one to several thousand mitochondria, depending on the cell's level of energy consumption.
- As the amount of oxygen increased in the atmosphere billions of years ago and as successful aerobic prokaryotes evolved, evidence suggests that an ancestral cell with some membrane compartmentalization engulfed a free-living aerobic prokaryote, specifically an alpha-proteobacterium, thereby giving the host cell the ability to use oxygen to release energy stored in nutrients.
- Alpha-proteobacteria are a large group of bacteria that includes species symbiotic with plants, disease organisms that can infect humans via ticks, and many free-living species that use light for energy.
- These features all support that mitochondria were once free-living prokaryotes.
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- Mitochondria are organelles that are responsible for making adenosine triphosphate (ATP), the cell's main energy-carrying molecule.
- These features all support the hypothesis that mitochondria were once free-living prokaryotes.
- Mitochondria are often called the "powerhouses" or "energy factories" of a cell because they are responsible for making adenosine triphosphate (ATP), the cell's main energy-carrying molecule.
- ATP represents the short-term stored energy of the cell.
- Your muscle cells need a lot of energy to keep your body moving.
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- ATP is critical for muscle contractions because it breaks the myosin-actin cross-bridge, freeing the myosin for the next contraction.
- ATP first binds to myosin, moving it to a high-energy state.
- ADP and Pi remain attached; myosin is in its high energy configuration .
- As myosin expends the energy, it moves through the "power stroke," pulling the actin filament toward the M-line.
- At the end of the power stroke, the myosin is in a low-energy position.
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- The various types of energy include kinetic, potential, and chemical energy.
- The potential energy stored in molecules can be converted to chemical energy, which can ultimately be converted to kinetic energy, enabling an organism to move.
- Energy associated with objects in motion is called kinetic energy.
- The jet engines are converting potential energy in fuel to the kinetic energy of movement.
- This type of potential energy is called chemical energy, and like all potential energy, it can be used to do work.
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- All organisms require energy to complete tasks; metabolism is the set of the chemical reactions that release energy for cellular processes.
- Plants convert light energy from the sun into chemical energy stored in molecules during the process of photosynthesis.
- Some of these chemical reactions are spontaneous and release energy, whereas others require energy to proceed.
- Energy is needed to perform heavy labor and exercise, but humans also use a great deal of energy while thinking and even while sleeping.
- Just as energy is required to both build and demolish a building, energy is required for both the synthesis and breakdown of molecules.
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- Animals use energy for metabolism, obtaining that energy from the breakdown of food through the process of cellular respiration.
- Animals need food to obtain energy and maintain homeostasis.
- Adenosine triphosphate, or ATP, is the primary energy currency in cells.
- ATP stores energy in phosphate ester bonds, releasing energy when the phosphodiester bonds are broken: ATP is converted to ADP and a phosphate group.
- ATP is the energy molecule of the cell.