Final answer:
The statement is true; the cell does require ATP for muscle contraction and for building molecules, as ATP is the main energy currency used for various cellular functions.
Step-by-step explanation:
The statement that the cell needs ATP for flexing muscles and for building molecules is true. Adenosine triphosphate, or ATP, is known as the body's fuel source and is vital for various cellular processes. In terms of muscle contraction, ATP provides the necessary energy for cross-bridge formation and filament sliding, which are essential for muscles to contract. Moreover, ATP is necessary to build organic molecules, a process that is fundamental for cell growth, repair, and normal function.
ATP is also involved in driving other cellular processes, such as the hydrolysis of ATP molecule during energy-requiring reactions and assisting in electrical signal transmission in nerve cells. It is, without a doubt, the useable form of energy for your cells, acting as the energy currency within the biological systems. In essence, the role of ATP in cells is to capture and transfer energy for an extensive range of cellular functions, including both the contraction of muscles during physical activity and the synthesis of biomolecules, which is a core aspect of metabolism.