Key Vocabulary
Define metabolic pathway.
A series of enzyme-catalyzed reactions that convert a starting molecule into a final product.
Where does glycolysis occur and does it require oxygen?
It occurs in the cytoplasm and does not require oxygen.
Where do the light-dependent reactions occur?
In the thylakoid membranes of the chloroplast.
A graph shows oxygen consumption increasing with glucose availability. Which process is occurring?
Cellular respiration.
Explain how ATP hydrolysis is coupled to endergonic reactions.
ATP hydrolysis releases energy and transfers a phosphate group, driving endergonic reactions.
What is the role of ATP in cellular energetics?
ATP transfers energy by phosphorylating other molecules, making reactions energetically favorable.
Explain why oxygen is essential for the electron transport chain.
Oxygen is the final electron acceptor, allowing the ETC to continue functioning.
What is the role of water in photosynthesis?
Water is split to provide electrons, releasing oxygen.
If proton flow through ATP synthase is blocked, what happens to ATP production?
ATP production stops.
Describe how the structure of the mitochondrion increases ATP production.
Folded inner membranes increase surface area for the ETC.
Distinguish between oxidation and reduction.
Oxidation is loss of electrons; reduction is gain of electrons.
Predict what happens to ATP production if the Krebs cycle stops.
ATP production decreases because fewer electron carriers reach the ETC.
Explain why the Calvin cycle depends on the light reactions.
It requires ATP and NADPH produced by the light reactions.
A plant exposed to high light intensity shows increased oxygen production. Which reaction is responsible?
Light-dependent reactions.
Explain how photosynthesis and respiration are interdependent.
Photosynthesis produces glucose and oxygen used in respiration; respiration produces CO₂ used in photosynthesis
What is the function of NADH and FADH₂?
They carry high-energy electrons to the electron transport chain.
Why does fermentation allow glycolysis to continue?
It regenerates NAD⁺ needed for glycolysis.
Predict what happens if a plant is placed in darkness
Light reactions stop, leading to decreased Calvin cycle activity.
Explain why increasing temperature initially increases enzyme activity.
Molecules move faster, increasing collision rates.
Predict the effect of a toxin that inhibits ATP synthase.
Cells would experience an energy shortage and fail to maintain homeostasis
Define chemiosmosis.
The movement of protons across a membrane through ATP synthase to generate ATP.
Explain why most ATP is produced during oxidative phosphorylation.
The proton gradient drives ATP synthase, producing large amounts of ATP.
Identify the main product of the Calvin cycle.
G3P (a sugar used to form glucose).
Predict the effect of a pH change on enzyme function.
Enzyme activity decreases if pH moves away from the optimal range.
Analyze why both photosynthesis and respiration rely on redox reactions.
Energy transfer occurs through electron movement between molecules.