Cellular Energetics
Photosynthesis and cellular respiration are essential processes for life. Which statement correctly compares these two processes?
Photosynthesis produces glucose, while cellular respiration consumes glucose.
Photosynthesis occurs in mitochondria, while cellular respiration occurs in chloroplasts.
Photosynthesis and cellular respiration both produce oxygen.
Photosynthesis and cellular respiration both consume carbon dioxide.
How do changes in temperature and pH affect enzyme activity?
Enzymes are not affected by temperature or pH.
Enzymes function optimally regardless of temperature or pH.
Enzymes have an optimal temperature and pH range; deviations can lead to denaturation.
Enzymes function better at extreme temperatures and pH levels.
How is the proton gradient generated and used in the light-dependent reactions to produce ATP?
The electron transport chain transfers electrons, creating a proton gradient, which ATP synthase uses to make ATP.
The Calvin cycle directly pumps protons across the membrane to create the gradient.
Photosystems I and II directly use light energy to pump protons across the membrane.
Water molecules are split, releasing protons that create the gradient.
Which molecule serves as the primary energy currency of the cell, powering most cellular activities?
Glucose
ATP (adenosine triphosphate)
NADPH
Enzyme
Which of the following best describes entropy in the context of living systems?
A measure of perfect order and organization.
A measure of disorder or randomness.
The energy available to do work.
The total energy in a closed system.
In cells, energy-releasing processes are often coupled with energy-requiring processes. Which of the following is an example of this coupling?
The breakdown of glucose to release energy, which is then used to synthesize ATP.
The synthesis of proteins directly releasing heat.
The transport of molecules across the cell membrane without energy input.
The increase of entropy without energy input.
What are the primary reactants of photosynthesis?
Glucose and oxygen
Carbon dioxide and water
ATP and NADPH
Sugars and oxygen

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If a toxin inhibits the production of ATP in a cell, which of the following processes would be most immediately affected?
DNA replication
Active transport
Passive transport
Protein synthesis
A scientist is studying an enzyme-catalyzed reaction and observes that the reaction rate decreases significantly when a specific molecule binds to the enzyme at a site distinct from the active site. This is most likely an example of:
Competitive inhibition
Noncompetitive inhibition
Uncompetitive inhibition
Feedback activation
What is the primary role of an enzyme in a chemical reaction within a cell?
To increase the activation energy of the reaction.
To decrease the activation energy of the reaction.
To be consumed during the reaction.
To change the equilibrium of the reaction.