Biochemical Pathways and Energy Coupling Quiz

<p>Metabolism</p> Signup and view all the answers

<p>Decreases it</p> Signup and view all the answers

<p>Anabolism</p> Signup and view all the answers

<p>Non-spontaneous work</p> Signup and view all the answers

<p>To produce complex molecules</p> Signup and view all the answers

<p>Catabolism</p> Signup and view all the answers

<p>Basic building blocks</p> Signup and view all the answers

<p>To provide energy for cellular work and minimize heat loss</p> Signup and view all the answers

<p>It acts as a barrier to the reaction taking place</p> Signup and view all the answers

<p>By lowering the energy activation and allowing the reactants to achieve the transition state</p> Signup and view all the answers

<p>Enzymes are central to controlling metabolism</p> Signup and view all the answers

<p>Catalysts decrease the EA, allowing spontaneous reactions to occur</p> Signup and view all the answers

<p>Cells control metabolism by controlling the amount of enzymes and their regulatory properties</p> Signup and view all the answers

<p>To regulate metabolic pathways by inhibiting the first dedicated enzyme of a pathway</p> Signup and view all the answers

<p>To show specificity and control metabolism</p> Signup and view all the answers

<p>Because catalysts decrease the EA, allowing spontaneous reactions to occur</p> Signup and view all the answers

<p>To have a high G and act as a barrier to the reaction</p> Signup and view all the answers

<p>Gibbs free energy (G)</p> Signup and view all the answers

<p>Free energy change (ΔG)</p> Signup and view all the answers

<p>Adenosine triphosphate (ATP)</p> Signup and view all the answers

<p>ATP hydrolysis</p> Signup and view all the answers

<p>A spontaneous reaction</p> Signup and view all the answers

<p>Energy coupling</p> Signup and view all the answers

<p>Biochemical pathways</p> Signup and view all the answers

<p>Entropy (S)</p> Signup and view all the answers

<p>Hexokinase</p> Signup and view all the answers

<p>Calvin cycle</p> Signup and view all the answers

<p>Biochemical pathways are governed by the laws of thermodynamics, which state that energy is conserved and every energy transformation increases the entropy of the universe. The second law of thermodynamics implies that all energy is eventually converted into heat, which cannot be used by cells to perform work.</p> Signup and view all the answers

<p>Adenosine triphosphate (ATP) is the energy currency of a cell and is consumed during various types of cellular work. ATP hydrolysis is a common coupling reaction used to drive forward nonspontaneous reactions in cells.</p> Signup and view all the answers

<p>At the cellular level, energy coupling can be analogized to water at the top of a dam, electricity, and making toast. Just as the potential energy of water at the top of a dam can be harnessed to perform work, cells use energy coupling to drive energy-requiring processes.</p> Signup and view all the answers

<p>Enzymes speed up biochemical reactions by lowering the activation energy, allowing reactants to achieve the transition state more easily. They are essential for cellular metabolism because most biochemical reactions have a high activation energy, and without enzymes, these reactions would not occur at an appreciable rate.</p> Signup and view all the answers

<p>Catalysts lower the activation energy of spontaneous reactions, allowing them to occur at a faster rate. Catalysts are needed because spontaneous reactions may not occur at an appreciable rate if the activation energy is large, and catalysts decrease the activation energy, making the reactions more likely to happen.</p> Signup and view all the answers

<p>Cells control metabolism by using enzymes to catalyze biochemical reactions. Regulatory enzymes are important in metabolic pathways because they can be up-regulated or down-regulated, allowing cells to control the rate of specific reactions and overall metabolic processes.</p> Signup and view all the answers

<p>Feedback inhibition is a regulatory mode in which the end-product of a metabolic pathway inhibits an earlier enzyme in the pathway, slowing down the production of more product. It is common in metabolic pathways because it helps maintain homeostasis by preventing the overproduction of certain substances.</p> Signup and view all the answers

<p>Metabolism is the sum of anabolism and catabolism. Anabolism involves building complex molecules from simpler ones, while catabolism breaks down complex molecules into simpler ones. Together, they represent the biochemical reactions of an organism or cell, with catabolism making energy available for cellular work.</p> Signup and view all the answers

<p>Spontaneous work is a process that can happen on its own, without the input of external energy, while non-spontaneous work requires external energy input for the process to occur. An example of spontaneous work is water flowing down a dam, while non-spontaneous work includes water moving back up the dam.</p> Signup and view all the answers

<p>A cell engages in catabolism to remove complex molecules that are no longer useful, releasing monomers for recycling; to provide basic building blocks for producing monomers; and to make existing potential energy available for cellular work.</p> Signup and view all the answers