In this week’s discussion, we will explore the production of ATP in the human body. The overall process of cellular respiration (described in an overview format in the 14-minute video below) is the production of between 30 and 38 molecules of ATP for every molecule of glucose (ATP is contained in “Energy” in the chemical equation below).
The energy necessary to sustain life is harvested by the food we eat. Most nutrition labels highlight the amount of energy, in units of calories, released from carbohydrates, proteins, and fats. Here, we consider only the processes by which carbohydrates (in the form of glucose) generate ATP.
ATP is produced from glucose in three steps: (1) glycolysis, (2) the Krebs cycle, and (3) The electron transport chain. We will not go into details about the many chemical reactions involved in each of these three pathways, rather, we will consider only the numbers of ATP molecules generated from each step (from one glucose molecule).
Watch the Khan Academy Cellular Respiration Introduction video, and then respond to the prompts below.
Classify the type of chemical reaction represented above.
After watching the video, identify the three stages of cellular respiration. Be sure to point out whether each step is aerobic, which means it requires oxygen, or anaerobic, which means it does not require oxygen.
Next, identify how many ATP molecules are generated in each step of cellular respiration.
Lastly, please describe in a couple sentences why oxygen is necessary for the aerobic steps in cellular respiration. After all, approximately 20% of the air we breathe is oxygen, and approximately 80% is nitrogen. Why isn’t nitrogen used in respiration instead of oxygen? To guide your answer, please consider the electronegativity of oxygen