Devon-Jake-CR+essays

26. Tom notices that he 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 more short of breath after r﻿unning a 200 meter sprint because he used oxygen faster than he can gain it back putting his cells in oxygen debt. His body starts to breathe faster and his heart pumps faster in order for him to be able to get all of the oxygen he needs. When he was jogging his body was able to recieve oxygen at a steady rate while he was using it. Having this equal balance caused him to not be short of breath.

27. A scientist isolates mitochondria form 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. How 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).

When acid is placed in a solution hydrogen ions are released. In the last stage of cellular respiration during the ETC hydrogen moves across the inner membrane from the intermembranous space to the matrix through the ATP synthase. The acid released hydrogen ions in the intermembranous space. These ions naturally move from high concentration to low concentration while traveling through the ATP synthase. The ATP synthase attaches ADP and a phosphate to make ATP. That is how it is possible for the mitochondria to continue making ATP without glucose.

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 mis-shapen, 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.

The ETC is the final stage of cellular respiration and produces the most ATP. Since one of Helen's ETC proteins is mis-shapen, it is having trouble pumping the hydrogen ions. Since the hydrogen ions are not being pumped as efficiently they won't pass through ATP synthase as fast. Since the hydrogen ions are not passing through as fast her body can't make all of the ATP that is needed for her cells to grow and divide normally. This results in Helen having low weight. Without ATP her body won't develop properly and she will not reach the development milestones.

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

During photoshnthesis energy starts out in the form of sunlight when it enters the chloroplasts in a plant cell.. The energy is transfered from sunlight energy into chemical energy that is stored in the bonds of glucose. It uses water and carbon dioxide and releases oxygen while doing this. In cellular respiration the bonds of glucose are broken and the energy is transfered from electrons into useable energy stored in the bonds of ATP. This happens aerobically or anaerobically during glycosis, the citric acid cycle, and the electron transport chain.

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?

In biochemical reactions ATP is used to make and break bonds and is needed for all reactions to occur. An example is during the calvin cycle when the RuBP and carbon dioxide are transformed into G3P. ATP in our cells is used for energy. Our cells get energy out of ATP by breaking the bond between phosphates. The molecule of ATP then becomes ADP. It is recharged by attaching a phosphate to ADP and therefore becomes ATP again.