📚 Topic Summary
The Electron Transport Chain (ETC) and Chemiosmosis are the final stages of cellular respiration, where most of the cell's ATP (energy currency) is produced. The ETC involves a series of protein complexes embedded in the inner mitochondrial membrane that pass electrons from one molecule to another, ultimately reducing oxygen to water. This electron flow generates a proton gradient across the membrane. Chemiosmosis uses the energy stored in this proton gradient to drive ATP synthesis by ATP synthase.
🧪 Part A: Vocabulary
Match the following terms with their definitions:
| Term |
Definition |
| 1. Electron Transport Chain |
A. The enzyme that uses the proton gradient to synthesize ATP |
| 2. ATP Synthase |
B. The process of using a proton gradient to drive ATP synthesis. |
| 3. Chemiosmosis |
C. A series of protein complexes that transfer electrons. |
| 4. Proton Gradient |
D. The final electron acceptor in the electron transport chain. |
| 5. Oxygen |
E. The difference in proton concentration across a membrane. |
Answer Key: 1-C, 2-A, 3-B, 4-E, 5-D
🧬 Part B: Fill in the Blanks
Complete the following paragraph using the words: mitochondria, ATP, protons, electron, oxygen.
The electron transport chain is located in the inner membrane of the __________. It uses energy from the __________ to pump __________ across the membrane, creating a gradient. This gradient drives the synthesis of __________. The final electron acceptor in the chain is __________.
Answer Key: mitochondria, electron, protons, ATP, oxygen
🤔 Part C: Critical Thinking
Explain how the electron transport chain and chemiosmosis are interdependent processes. What would happen if one stopped working?