* Growth and repair: Cells need energy to synthesize new molecules and repair damaged ones.
* Movement: Muscle cells use ATP to contract and allow movement.
* Active transport: Cells need energy to move substances across their membranes against their concentration gradient.
* Signal transduction: Cells use energy to transmit signals between different parts of the cell and with other cells.
In essence, cellular respiration breaks down glucose in the presence of oxygen to release energy that is stored in ATP molecules. This process is crucial for the survival and functioning of all living organisms.
