1. Why is respiration important to humans? 2. Write the equations for aerobic and anaerobic respiration in humans. 3. Suggest two reasons why we need energy when we sleep.

1. **Importance of Respiration** - Respiration is essential for humans because it provides the energy needed for all bodily functions. Energy is released during the breakdown of food molecules, which is then used to produce adenosine triphosphate (ATP), the “energy currency” of the cell. - The process also allows for the removal of carbon dioxide, a waste product of metabolism, which helps maintain the acid-base balance of the body. 2. **Equations for Respiration** - **Aerobic Respiration:** In the presence of oxygen, cells break down glucose to produce carbon dioxide, water, and ATP. The equation is: \[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)} \] - **Anaerobic Respiration:** In the absence of oxygen, such as during intense exercise, human cells convert glucose into lactic acid and ATP. The equation is: \[ C_6H_{12}O_6 \rightarrow 2C_3H_6O_3 + \text{Energy (ATP)} \] 3. **Reasons for Needing Energy While Sleeping** - **Cellular Repair and Maintenance:** Even during sleep, the body is actively repairing tissues, synthesizing proteins, and performing various cellular maintenance tasks. Energy is necessary for these processes. - **Brain Function and Memory Consolidation:** Sleeping is a critical period for the brain to consolidate memories, process new information, and maintain neuronal health. This requires energy to support the complex biochemical processes involved in brain function.