26. Tom notices that is a lot more short of breath after he finishes a 200 meter sprint than when he jogs for 3 miles. He is confused because he feels as if he should feel more tired when he runs for a much longer distance. Explain to him why it makes sense that he is indeed more short of breath after running a sprint than jogging. Make sure to explain it using your scientific knowledge of cellular respiration.

  • Tom is short of breath because he needs to breathe faster to take in more O2. Tom needs to take in more O2 to be used during the Krebs/Citric Acid Cycle and to be the final electron acceptor in the ETC, which voids the most ATP molecules. When he sprints, he doesn't have as much time to take in O2 and he needs more energy to be able to have those sudden bursts of speed. Also, when you sprint, it is harder for your blood to get all the oxygen that your cells need to your cells. So, he needs to breathe faster to get more oxygen into his blood stream to get them into his cells to be used to make ATP for sudden bursts of energy made in the Krebs Cycle and ETC, which use oxygen.

27. A scientist isolates mitochondria from human cells and places them in an acid solution. The acid penetrates the intermembranous space of the mitochondria. The scientist then notices that the mitochondria start making ATP despite the fact that he is not providing any glucose for them. HOs is it possible that the mitochondria are still making ATP? (Think back to what an acid is, what it releases when placed in a solution and why this would make the mitochondria synthesize ATP).

  • The acid is a carbonic acid which H2CO3. So when the acid is placed into the solution H ions are released. This will make the ETC or chemiosmosis to make energy. The H ions are in the intermembranous space, so they get transported actively through channel proteins by the electrons. Now, there is a high concentration of H ions in the matrix. These H ions then go back out throught the ATP synthase, by facilitated diffusion, and create ATP.

28. Genetic testing reveals that baby Helen has a defective gene that results in the defective production of one of the proteins in the electron transport chain. Because of faulty instructions in her DNA, one of the proteins in her ETC is misshapen, and therefore it cannot perform its function as efficiently. Baby Helen is "failing to thrive" as she is having a hard time gaining weight and reaching developmental milestones. Using your knowledge of the ETC and its role in making ATP, explain why you think baby Helen is having the problems described above.

  • Since baby Helen has a defective protein in the ETC, she has trouble using glucose. Because of this, she uses her fat deposits to make energy. That is why she is having trouble gaining weight. The reason she is having a hard time reach developmental milestones is because she is not able to make enough energy to help her grow and develop.

29. Compare the basic transformation of energy during photosynthesis and cellular respiration.

  •  For photosynthesis it needs sunlight energy, carbon-dioxide, and water to make oxygen and glucose. The formula for this would be: Sunlight + CO2 + H20 -> O2 + C6H12O6 The energy in sunlight is converted into the energy in glucose. The CO2 and H20 help with this process. O2 is just a by-product. For cellular respiration it needs glucose and oxygen to make carbon dioxide, water, and Adenosine-triphosphate. The formula for this would be: O2 + C6H12O6 -> CO2 + H2O + ATP. The energy in glucose is broken up and converted into the energy in ATP. The O2 helps with this process. CO2 and H2O are by-products.

30. Describe the role of ATP in biochemical reactions. What is ATP used for in your cells? How do your cells get energy out of a molecule of ATP? How is ATP recharged?

  • ATP is used for many, many, many biochemical reactions throughout your body. ATP molecules are used for energy to do almost every activity in your body. ATP is used for many things in your cells. Just to name a few there is endocytosis, excocytosis, phagocytosis, pinocytosis, etc. The way your cells get energy out of a molecule of ATP is by breaking bonds. There is a bond between ADP and a phosphate molecule. When this bond is broken, energy is released. ATP is recharged by the ADP and P being bonded together in ATP synthase.