1. Explain why humans require oxygen to survive and discuss the metabolic consequences of oxygen deprivation (hypoxia) such as during drowning or high altitude climbing. Include in your answer a discussion of the 2019 Nobel Prize winning work in Physiology or Medicine by William G. Kaelin, Jr., Sir Peter J. Ratcliffe and Gregg L. Semenza for their discoveries of how cells sense and adapt to oxygen availability.

Oxygen is taken inside the body and carbon dioxide is taken out of the body in a process known as respiration. Oxygen is crucial for living because it is required for the breakdown of nutrients inside the cell to gain energy. All the food we eat will be useless if there would be no oxygen present. The cell utilize the oxygen for the breakdown of nutrients to produce energy, otherwise they can't survive. Blood supply the oxygen and nutrients to different parts of body and any damage to blood vessel can cause damage to crucial organs of the body like heart due to lack of oxygen.

We can breath easily at normal places because of normal atmospheric pressure of air (oxygen). There is low atmospheric pressure at high altitude that cause lower oxygen intake of body, which results in deficiency of oxygen in body known as hypoxia. A person may feel anxiety, dizziness and rapid heart rate etc during hypoxia. During hypoxia the body increased the production of red blood cell that can carry more oxygen to deal with it.

William G. Kaelin, Jr., Sir Peter J. Ratcliffe and Gregg L. Semenza said that whenever there will be shortness of oxygen the body will detect it and try to accomplish it by producing hypoxia identification factor in the cell. That activates the genes associated with oxygen to deal with the condition.