Bioenergetics and Enzyme Catalysis

It allows prediction of the direction of chemical reactions, their equilibrium position, and the work they can perform.

Heterotrophic cells acquire it from nutrient molecules, while photosynthetic cells obtain it from absorbed solar radiation.

Enzymes lower the activation energy, allowing reactions to proceed more quickly at body temperature.

<p>No, enzymes cannot change equilibrium constants; they can only increase the rate of reaction.</p> Signup and view all the answers

<p>It can be driven forward by coupling it to a highly exergonic reaction.</p> Signup and view all the answers

<p>It means the overall reaction’s free-energy change can be determined by the sum of the individual changes.</p> Signup and view all the answers

<p>The synthesis has a positive ΔG′° value, predicting that it will not proceed spontaneously under standard conditions.</p> Signup and view all the answers

<p>Anabolic processes build complex molecules requiring energy, while catabolic processes break down complex molecules releasing energy.</p> Signup and view all the answers

<p>The first law states that energy cannot be created or destroyed, only transformed or transferred.</p> Signup and view all the answers

<p>The second law states that in natural processes, the entropy of the universe tends to increase, leading to greater disorder.</p> Signup and view all the answers

<p>NADH stores energy used to drive ATP synthesis.</p> Signup and view all the answers

<p>Bioenergetics is the study of energy transformations in living cells and their underlying chemical processes.</p> Signup and view all the answers

<p>Anabolic processes build complex molecules from simpler ones, while catabolic processes break down complex molecules into simpler ones.</p> Signup and view all the answers

<p>Cells regulate enzyme activity by changing the number of enzyme molecules or the catalytic activity of existing enzymes.</p> Signup and view all the answers

<p>Free energy (G) represents the energy available to do work during a reaction at constant temperature and pressure.</p> Signup and view all the answers

<p>Living systems are open systems because they continuously exchange material and energy with their surroundings.</p> Signup and view all the answers

<p>Energy transduction refers to the process of converting one form of energy into another within cellular contexts.</p> Signup and view all the answers

<p>Organisms create order by continually exchanging energy and material with their surroundings, preventing equilibrium.</p> Signup and view all the answers

<p>They maintain different concentrations in compartments, influencing metabolic rates through kinetic control.</p> Signup and view all the answers

<p>Key enzymes can be activated allosterically or by altering their synthesis and breakdown rates.</p> Signup and view all the answers

<p>ATP acts as the universal energy currency that provides energy for cellular work.</p> Signup and view all the answers

<p>Cells couple energy-releasing (exergonic) reactions, such as ATP cleavage, to endergonic reactions.</p> Signup and view all the answers

<p>They provide energy by oxidizing substrates, which is conserved in reduced cofactors like NADH.</p> Signup and view all the answers

<p>Energy transduction refers to the conversion of one form of energy into another, enabling biochemical work.</p> Signup and view all the answers

<p>The free-energy change indicates the maximum energy available to do work during a reaction.</p> Signup and view all the answers

<p>They regulate and integrate metabolic activities across different tissues from outside the cells.</p> Signup and view all the answers

<p>Anabolic processes build complex molecules, while catabolic processes break down molecules to release energy.</p> Signup and view all the answers

<p>It allows for better control of metabolic rates and the efficient regulation of energy use.</p> Signup and view all the answers

<p>A negative ΔG indicates that the reaction is exergonic and releases free energy, making it energetically favorable.</p> Signup and view all the answers

<p>Exothermic reactions have a negative ΔH as they release heat, while endothermic reactions have a positive ΔH as they absorb heat.</p> Signup and view all the answers

<p>A positive ΔS indicates an increase in disorder, which contributes to making ΔG negative and favoring spontaneity.</p> Signup and view all the answers

<p>Anabolic processes build complex molecules from simpler ones and are generally endergonic, while catabolic processes break down complex molecules into simpler ones and are typically exergonic.</p> Signup and view all the answers

<p>Temperature (T) can affect ΔG through its role in the equation ΔG = ΔH - TΔS, where a higher temperature can increase the impact of ΔS.</p> Signup and view all the answers

<p>ΔG′° is a physical constant for a specific reaction and is calculated using ΔG′° = -RT ln K′ eq.</p> Signup and view all the answers

<p>Bioenergetics studies energy relationships and conversions in biological systems, which are fundamental to metabolism.</p> Signup and view all the answers

<p>Anabolic processes involve the synthesis of complex molecules from simpler ones, while catabolic processes break down complex molecules into simpler ones.</p> Signup and view all the answers

<p>ATP hydrolysis releases energy, which drives various endergonic reactions in metabolic pathways.</p> Signup and view all the answers

<p>ΔG represents the net effect of enthalpy and entropy, predicting the spontaneity and stability of reactants and products.</p> Signup and view all the answers

<p>ΔG is variable because it depends on concentrations of reactants and products, whereas ΔG′° is constant for a specific reaction.</p> Signup and view all the answers

<p>Energy transduction refers to the conversion of energy from one form to another within cells to perform work.</p> Signup and view all the answers

<p>Entropy represents the degree of randomness and influences the free-energy change, impacting the direction of metabolic reactions.</p> Signup and view all the answers

<p>A negative ΔG′° indicates a reaction that tends to proceed spontaneously in the forward direction, while a positive ΔG′° suggests it would not occur without energy input.</p> Signup and view all the answers

<p>The hydrolysis of ATP provides the energy necessary to drive the endergonic synthesis of glucose 6-phosphate from glucose and inorganic phosphate.</p> Signup and view all the answers