Questions: The electron transport system is found in the of the inner folds of the mitochondria.
cristae
intermembrane space
lumen
cytoplasm
Transcript text: The electron transport system is found in the $\qquad$ of the inner folds of the mitochondria.
cristae
intermembrane space
lumen
cytoplasm
Solution
The answer is the first one: cristae.
Explanation for each option:
Cristae: The electron transport system is located in the cristae of the inner mitochondrial membrane. The cristae are the folds of the inner membrane, which increase the surface area for the electron transport chain and ATP synthesis to occur. This is the correct answer.
Intermembrane space: This is the space between the inner and outer membranes of the mitochondria. While it plays a role in the electron transport chain by accumulating protons (H+ ions) to create a gradient, the electron transport chain itself is not located here.
Lumen: This term generally refers to the inside space of a tubular structure, but in the context of mitochondria, it is not a term typically used. The correct term for the space inside the inner membrane is the mitochondrial matrix, which is not where the electron transport chain is located.
Cytoplasm: The cytoplasm is the fluid that fills the cell outside the mitochondria. The electron transport chain is not located in the cytoplasm; it is specific to the inner mitochondrial membrane.
In summary, the electron transport system is found in the cristae of the inner folds of the mitochondria.