energy flow and recycling

• Energy transformation can be observed in situations where chemical energy is transformed into light and heat energy, as in the case of using flashcards to light candles or power cars.
• Energy transformation is useful in living organisms as it allows for different life processes, including growth, development, metabolism, and reproduction.
• Forms of energy include kinetic energy, potential energy, thermal energy, chemical energy, mechanical energy, and more.
• The first law of thermodynamics states that energy cannot be created nor destroyed; rather, energy can be changed from one form to another.
• The second law of thermodynamics states that energy cannot be changed from one form to another without a loss of usable energy.
• Entropy is used to indicate the relative amount of disorganization of a system and is the measure of randomness.
• The second law of thermodynamics can be exemplified in the breakdown of glucose and the movement of ions across the cell membrane, which naturally tend to proceed into a state of greater entropy.
• The ATP-ADP cycle in which ATP carries energy between exergonic and endergonic reactions is a mechanism of energy transformation.
• Mechanisms of ATP Synthesis include oxidative phosphorylation, substrate-level phosphorylation, and photophosphorylation.
• Substrate-level phosphorylation is the process of producing ATP by combining ADP and a phosphate group from a phosphorylated molecule instead of an inorganic phosphate.
• Oxidative phosphorylation is an ATP synthesizing mechanism that utilizes the energy derived from the transfer of electrons in an electron transport system to combine ADP and inorganic phosphate.
• Photophosphorylation is driven by the proton motive force generated during the flow of electrons in the light reaction stage.
• Consider a cell with certain energy content, from which we wish to extract as many processes as possible.
• Energy is defined as the ability to do work or bring about a change, allowing organisms to carry out different life processes, including growth, development, metabolism, and reproduction.
• Energy is absorbed from the surroundings as the reaction occurs, so the products of an endergonic reaction contain more chemical energy than the reactants did.
• Endergonic reactions require a net input of energy and yield products that are rich in potential energy.
• Protons flow through the ATP synthase enzyme complex, which triggers ATP synthesis.
• In cells, potential energy is in the form of chemical energy stored in the chemical bonds of biomolecules.
• Endergonic reactions are energy-releasing processes where the reactants have less energy than the products.
• Earth does not go up in flames because of the first law of thermodynamics, which states that energy cannot be created nor destroyed, but it can be changed from one form to another.
• Exergonic reactions begin with reactants whose covalent bonds contain more potential energy than those in products.
• Graphical representation of energy coupling in cells.
• The first law of thermodynamics, the law of conservation of energy, states that energy cannot be created nor destroyed, but it can be changed from one form to another.
• Breaking the bond between the ADP and inorganic phosphate releases energy, which can be used for coupled reactions.
• Cells have the capacity to convert one form of energy into another, for example, plants convert solar energy into chemical energy in sugar molecules.
• Kinetic energy is the energy of motion, while potential energy is a stored energy whose capacity to accomplish work is not being used at the moment.
• Exergonic reactions are energy-releasing processes where the reactants have greater energy than the products.
• ATP is synthesized through three mechanisms: substrate-level phosphorylation, oxidative phosphorylation, and photophosphorylation.
• A biological example of an endothermic reaction is photosynthesis.
• The term entropy is used to indicate the relative amount of disorganization, and the universe moves in the direction of greater entropy.
• Should the system’s entropy be high or low?
• The reaction releases to the surroundings an amount of energy equal to the difference in potential energy between the reactants and the products.
• The second law of thermodynamics applies to living systems and states that energy cannot be changed from one form to another without a loss of usable energy.
• An endergonic reaction starts with reactants that contain relatively little potential energy.