Final answer:
Without oxygen, human cells switch from aerobic respiration to anaerobic glycolysis for ATP production, which is less efficient and increases acidity within cells. Red blood cells, which only use glycolysis, would die if this pathway were blocked. Prolonged oxygen deprivation can lead to tissue damage, especially in the brain.
Step-by-step explanation:
Understanding Cellular Response to Lack of Oxygen When human cells are deprived of oxygen, they cannot produce adenosine triphosphate (ATP) through aerobic respiration. Normally, oxygen plays a crucial role in the mitochondrial process of ATP production. Without it, cells must rely on anaerobic glycolysis to generate ATP, which is less efficient and results in the production of lactic acid as a byproduct. This shift facilitates a limited energy supply and can lead to an acidic intracellular environment. Human red blood cells (RBCs) are unique in that they do not perform aerobic respiration at any time because they lack mitochondria. They solely depend on glycolysis for their ATP needs. If glycolysis were blocked in RBCs, they could not generate ATP and would eventually die, as this process is their only source of energy.
In the absence of sufficient oxygen, as seen during strenuous exercise or in conditions such as hypoxia, our body systems adjust to maintain homeostasis. For instance, muscles switch to anaerobic metabolism, leading to lactic acid buildup. If the situation continues, bodily functions are impaired, which can result in damage to tissues, especially those such as brain cells, that are highly dependent on a consistent supply of ATP.