{"answerArea": {"calculator": false, "chi2Table": false, "periodicTable": false, "tTable": false, "zTable": false}, "hints": [{"content": "All of the electrons that enter the transport chain come from NADH and FADH2, which are produced during earlier phases of cellular respiration. \n \nIn the electron transport chain (ETC), NADH and FADH2 are then oxidized to form NAD+ and FAD, respectively so they can be reused in other steps of cellular respiration.\n\n", "images": {}, "replace": false, "widgets": {}}, {"content": "NADH is a better electron donor than FADH2 because NADH has electrons at a high level, allowing it to transfer electrons directly to complex I in the ETC. As electrons move through complex I, energy is released, and H+ ions are pumped across the membrane.\n\nConversely, FADH2 has electrons at a lower energy level, so it cannot transfer its electrons to complex I in the ETC. Instead, it feeds them into the ETC through complex II, which does not pump H+ ions across the membrane.", "images": {}, "replace": false, "widgets": {}}, {"content": "The correct answer is\n\nAll of the electrons that enter the transport chain (ETC) come from NADH and FADH2 molecules which are produced during earlier phases of cellular respiration.", "images": {}, "replace": false, "widgets": {}}], "itemDataVersion": {"major": 0, "minor": 1}, "question": {"content": "NADH and FADH2 are electron carriers that are involved in oxidative phosphorylation, the final step of cellular respiration.\n\n**Which of the following is true of electron carriers NADH and FADH2?**\n\n[[☃ radio 1]]", "images": {}, "widgets": {"radio 1": {"alignment": "default", "graded": true, "options": {"choices": [{"clue": "NADH is a better electron donor than FADH2.\n\nNADH is a better electron donor than FADH2 because NADH has electrons at a high level, allowing it to transfer electrons directly to complex I in the ETC. As electrons move through complex I, energy is released, and H+ ions are pumped across the membrane.\n\nConversely, FADH2 has electrons at a lower energy level, so it cannot transfer its electrons to complex I in the ETC. Instead, it feeds them into the ETC through complex II, which does not pump H+ ions across the membrane.", "content": "FADH2 is a better electron donor than NADH because it allows more H+ ions to be pumped across the membrane.", "correct": false}, {"clue": "Reduced electron carriers NADH and FADH2 are produced during glycolysis, pyruvate oxidation, and the Krebs cycle. They then provide the electrons that begin the ETC.", "content": "All of the electrons that enter the transport chain (ETC) come from NADH and FADH2 molecules which are produced during earlier phases of cellular respiration.", "correct": true}, {"clue": "When NADH and FADH2 pass their electrons to the electron transport chain (ETC), they turn back into NAD+ and FAD, which can then be reused in other parts of cellular respiration.", "content": "NADH and FADH2 are single-use molecules so once they donate their electrons, they cannot be used again.", "correct": false, "isNoneOfTheAbove": false}, {"clue": "NADH is the reduced form of NAD+ while FADH2 is the reduced form of FAD.", "content": "NADH is the oxidized form of NAD+ and FADH2 is the reduced form of FADH.", "correct": false, "isNoneOfTheAbove": false}], "countChoices": false, "deselectEnabled": false, "displayCount": null, "hasNoneOfTheAbove": false, "multipleSelect": false, "randomize": false}, "static": false, "type": "radio", "version": {"major": 1, "minor": 0}}}}}