A Level Biology Practice Exam

Which of the following processes requires energy from the hydrolysis of ATP?

1. Passive transport

2. Anabolic reactions

3. Simple diffusion

4. Endocytosis

The correct answer is: Anabolic reactions

The hydrolysis of ATP provides the energy necessary for anabolic reactions, which are processes that involve the synthesis of complex molecules from simpler ones. These reactions typically require energy input to form new chemical bonds and create more structured or larger molecules, such as proteins from amino acids or nucleic acids from nucleotides. ATP serves as the primary energy currency of the cell, and its hydrolysis to adenosine diphosphate (ADP) and inorganic phosphate releases energy that can be harnessed to drive these biosynthetic pathways. Anabolic reactions are essential for growth, repair, and the maintenance of cellular structures, making the energy derived from ATP a critical component of these processes. In contrast, passive transport and simple diffusion do not require energy input as they rely on the natural movement of molecules down their concentration gradient. Endocytosis also utilizes energy from ATP for membrane movement and engulfing substances but is distinct from anabolic reactions, which specifically refer to synthesis processes.