AP Chemistry Flashcards: Coupled Reactions

What this deck covers

This deck focuses on Coupled Reactions, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Identify a process where ATP synthesis is coupled to another reaction.

Answer: Oxidative phosphorylation. ATP synthesis is coupled to electron transport chain energy.

Flashcard 2: What does coupled reaction enable in cellular processes?

Answer: Efficient energy use. Coupling minimizes energy waste in cellular processes.

Flashcard 3: Which molecule often acts as a common intermediate in coupled reactions?

Answer: ATP. ATP connects exergonic and endergonic processes in metabolism.

Flashcard 4: What is a coupled reaction?

Answer: A reaction where an exergonic process drives an endergonic one. Energy from a favorable reaction powers an unfavorable one.

Flashcard 5: Identify the role of ATP in coupled reactions.

Answer: ATP acts as an energy carrier linking reactions. ATP transfers energy by releasing phosphate groups to drive reactions.

Flashcard 6: Which type of reaction is ATP hydrolysis?

Answer: Exergonic reaction. ATP hydrolysis releases energy spontaneously with negative $\Delta G$.

Flashcard 7: How do coupled reactions occur in cells?

Answer: They occur via shared intermediates, like ATP. Common molecules like ATP connect energy-releasing and energy-requiring reactions.

Flashcard 8: What is the primary function of ATP in metabolism?

Answer: To transfer energy via phosphate group transfer. Phosphorylation provides energy for cellular work and biosynthesis.

Flashcard 9: What is the role of enzymes in coupled reactions?

Answer: Enzymes lower activation energy, facilitating coupling. Enzymes catalyze both reactions in the coupling mechanism.

Flashcard 10: Which molecule often acts as a common intermediate in coupled reactions?

Answer: ATP. ATP connects exergonic and endergonic processes in metabolism.

Flashcard 11: Identify the intermediate formed during ATP hydrolysis.

Answer: ADP and inorganic phosphate (Pᵢ). These products carry energy and participate in further reactions.

Flashcard 12: What is the effect of ATP hydrolysis on reaction spontaneity?

Answer: It makes non-spontaneous reactions spontaneous. Energy coupling makes thermodynamically unfavorable reactions proceed.

Flashcard 13: What is ΔG in the context of coupled reactions?

Answer: Change in Gibbs free energy. Measures energy available for useful work in reactions.

Flashcard 14: Identify the intermediate formed during ATP hydrolysis.

Answer: ADP and inorganic phosphate (Pᵢ). These products carry energy and participate in further reactions.

Flashcard 15: What is a phosphorylated intermediate?

Answer: A substrate with added phosphate group from ATP. Activated molecules have increased reactivity for subsequent steps.

Flashcard 16: What is the energy currency of the cell?

Answer: ATP. ATP stores and transfers energy throughout the cell.

Flashcard 17: Identify a common cellular process that involves coupled reactions.

Answer: Muscle contraction. ATP hydrolysis provides energy for protein conformational changes.

Flashcard 18: State the relationship between Gibbs free energy and spontaneity.

Answer: Negative ΔG indicates spontaneous reaction. Thermodynamic favorability determines if reactions proceed without input.

Flashcard 19: What is the role of inorganic phosphate (Pᵢ) in energy transfer?

Answer: It participates in substrate-level phosphorylation. Pi can be transferred to form high-energy phosphate bonds.

Flashcard 20: Which reaction type is driven by ATP hydrolysis?

Answer: Endergonic reactions. ATP provides energy for non-spontaneous biosynthetic processes.

Flashcard 21: What happens to Gibbs free energy in exergonic reactions?

Answer: It decreases. Energy is released as the system becomes more stable.

Flashcard 22: What is a characteristic of endergonic reactions in terms of energy?

Answer: They require an input of energy. Energy must be supplied for products to form from reactants.

Flashcard 23: What is ΔG in the context of coupled reactions?

Answer: Change in Gibbs free energy. Measures energy available for useful work in reactions.

Flashcard 24: What is a characteristic of endergonic reactions in terms of energy?

Answer: They require an input of energy. Energy must be supplied for products to form from reactants.

Flashcard 25: What is the effect of ATP hydrolysis on reaction spontaneity?

Answer: It makes non-spontaneous reactions spontaneous. Energy coupling makes thermodynamically unfavorable reactions proceed.

Flashcard 26: State the equation for ATP hydrolysis.

Answer: ATP + H₂O → ADP + Pᵢ + energy. Hydrolysis breaks ATP bonds, releasing energy for cellular processes.

Flashcard 27: What is the role of NAD⁺/NADH in coupled reactions?

Answer: Electron carrier in redox reactions. Transfers electrons and energy between metabolic pathways.

Flashcard 28: What happens to Gibbs free energy in endergonic reactions?

Answer: It increases. Energy is absorbed to form less stable products.

Flashcard 29: What does 'endergonic' mean in terms of Gibbs free energy?

Answer: Endergonic reactions have a positive ΔG. Reactions require energy input and are non-spontaneous.

Flashcard 30: How is energy transferred in a coupled reaction?

Answer: Via transfer of phosphoryl groups or electrons. Chemical groups carry energy between reaction sites.

Flashcard 31: Which type of reaction is ATP hydrolysis?

Answer: Exergonic reaction. ATP hydrolysis releases energy spontaneously with negative $\Delta G$.

Flashcard 32: How does ATP hydrolysis affect reaction equilibrium?

Answer: It shifts equilibrium towards product formation. Energy release drives reactions toward completion.

Flashcard 33: What is the role of coenzymes in coupled reactions?

Answer: They assist enzymes in catalyzing reactions. Non-protein helpers facilitate enzyme-catalyzed energy transfer.

Flashcard 34: Which molecule is regenerated in coupled reactions involving ATP?

Answer: ADP is phosphorylated back to ATP. ATP is regenerated from ADP through phosphorylation reactions.

Flashcard 35: What does the term 'energy coupling' refer to?

Answer: Linking energy release from exergonic process to endergonic process. Mechanism transfers energy from favorable to unfavorable reactions.

Flashcard 36: What is a characteristic of exergonic reactions in terms of energy?

Answer: They release energy. Energy flows out, making products more stable than reactants.

Flashcard 37: Identify the process that uses ATP to power cellular work.

Answer: Mechanical work like muscle contraction. ATP hydrolysis powers myosin movement along actin filaments.

Flashcard 38: How does ATP provide energy to endergonic reactions?

Answer: By phosphorylating substrates, making them more reactive. Phosphate transfer activates molecules for subsequent reactions.

Flashcard 39: State the relationship between Gibbs free energy and spontaneity.

Answer: Negative ΔG indicates spontaneous reaction. Thermodynamic favorability determines if reactions proceed without input.

Flashcard 40: How is energy transferred in a coupled reaction?

Answer: Via transfer of phosphoryl groups or electrons. Chemical groups carry energy between reaction sites.

Flashcard 41: How does ATP hydrolysis affect reaction equilibrium?

Answer: It shifts equilibrium towards product formation. Energy release drives reactions toward completion.

Flashcard 42: Identify a reaction that is often coupled with ATP hydrolysis.

Answer: Protein synthesis. Translation requires ATP hydrolysis for amino acid assembly.

Flashcard 43: Which reaction type is driven by ATP hydrolysis?

Answer: Endergonic reactions. ATP provides energy for non-spontaneous biosynthetic processes.

Flashcard 44: What does coupled reaction enable in cellular processes?

Answer: Efficient energy use. Coupling minimizes energy waste in cellular processes.

Flashcard 45: Identify a common example of a coupled reaction in metabolism.

Answer: Glucose phosphorylation during glycolysis. ATP hydrolysis drives glucose activation in the first glycolytic step.

Flashcard 46: What is a phosphorylated intermediate?

Answer: A substrate with added phosphate group from ATP. Activated molecules have increased reactivity for subsequent steps.

Flashcard 47: Identify a process where ATP synthesis is coupled to another reaction.

Answer: Oxidative phosphorylation. ATP synthesis is coupled to electron transport chain energy.

Flashcard 48: What does 'exergonic' mean in terms of Gibbs free energy?

Answer: Exergonic reactions have a negative ΔG. Reactions release energy and occur spontaneously.

Flashcard 49: What does 'endergonic' mean in terms of Gibbs free energy?

Answer: Endergonic reactions have a positive ΔG. Reactions require energy input and are non-spontaneous.

Flashcard 50: What is the role of coupled reactions in metabolism?

Answer: They facilitate biosynthesis and cellular work. Energy coupling drives essential cellular functions efficiently.

Flashcard 51: What occurs to ATP in a coupled reaction?

Answer: It is hydrolyzed to ADP and Pᵢ. ATP breakdown releases energy for the coupled process.

Flashcard 52: Identify the role of ATP in coupled reactions.

Answer: ATP acts as an energy carrier linking reactions. ATP transfers energy by releasing phosphate groups to drive reactions.

Flashcard 53: What is the main purpose of coupling reactions in the cell?

Answer: To use energy from one reaction to drive another. Efficiently transfers energy between cellular processes.

Flashcard 54: State the equation for ATP hydrolysis.

Answer: ATP + H₂O → ADP + Pᵢ + energy. Hydrolysis breaks ATP bonds, releasing energy for cellular processes.

Flashcard 55: Which type of reaction is driven by the energy released from ATP hydrolysis?

Answer: Endergonic reactions. ATP hydrolysis provides energy for biosynthetic pathways.

Flashcard 56: How does ATP provide energy to endergonic reactions?

Answer: By phosphorylating substrates, making them more reactive. Phosphate transfer activates molecules for subsequent reactions.

Flashcard 57: What is the primary function of ATP in metabolism?

Answer: To transfer energy via phosphate group transfer. Phosphorylation provides energy for cellular work and biosynthesis.

Flashcard 58: Which type of reaction is driven by the energy released from ATP hydrolysis?

Answer: Endergonic reactions. ATP hydrolysis provides energy for biosynthetic pathways.

Flashcard 59: What is the energy currency of the cell?

Answer: ATP. ATP stores and transfers energy throughout the cell.

Flashcard 60: What is a coupled reaction?

Answer: A reaction where an exergonic process drives an endergonic one. Energy from a favorable reaction powers an unfavorable one.

Flashcard 61: What is the role of coupled reactions in metabolism?

Answer: They facilitate biosynthesis and cellular work. Energy coupling drives essential cellular functions efficiently.

Flashcard 62: What happens to Gibbs free energy in endergonic reactions?

Answer: It increases. Energy is absorbed to form less stable products.

Flashcard 63: Identify a common example of a coupled reaction in metabolism.

Answer: Glucose phosphorylation during glycolysis. ATP hydrolysis drives glucose activation in the first glycolytic step.

Flashcard 64: Identify a reaction that is often coupled with ATP hydrolysis.

Answer: Protein synthesis. Translation requires ATP hydrolysis for amino acid assembly.

Flashcard 65: Which molecule is regenerated in coupled reactions involving ATP?

Answer: ADP is phosphorylated back to ATP. ATP is regenerated from ADP through phosphorylation reactions.

Flashcard 66: What is a characteristic of exergonic reactions in terms of energy?

Answer: They release energy. Energy flows out, making products more stable than reactants.

Flashcard 67: What is the role of NAD⁺/NADH in coupled reactions?

Answer: Electron carrier in redox reactions. Transfers electrons and energy between metabolic pathways.

Flashcard 68: What happens to Gibbs free energy in exergonic reactions?

Answer: It decreases. Energy is released as the system becomes more stable.

Flashcard 69: What does ATP stand for?

Answer: Adenosine Triphosphate. Universal energy currency with three phosphate groups.

Flashcard 70: What is the role of coenzymes in coupled reactions?

Answer: They assist enzymes in catalyzing reactions. Non-protein helpers facilitate enzyme-catalyzed energy transfer.

Flashcard 71: What does 'exergonic' mean in terms of Gibbs free energy?

Answer: Exergonic reactions have a negative ΔG. Reactions release energy and occur spontaneously.

Flashcard 72: Identify a common cellular process that involves coupled reactions.

Answer: Muscle contraction. ATP hydrolysis provides energy for protein conformational changes.

Flashcard 73: Identify the process that uses ATP to power cellular work.

Answer: Mechanical work like muscle contraction. ATP hydrolysis powers myosin movement along actin filaments.

Flashcard 74: What is the main purpose of coupling reactions in the cell?

Answer: To use energy from one reaction to drive another. Efficiently transfers energy between cellular processes.

Flashcard 75: What does ATP stand for?

Answer: Adenosine Triphosphate. Universal energy currency with three phosphate groups.

Flashcard 76: What is the role of enzymes in coupled reactions?

Answer: Enzymes lower activation energy, facilitating coupling. Enzymes catalyze both reactions in the coupling mechanism.