Final answer:
The process that doesn't require energy within a cell is diffusion of small molecules, as it is a spontaneous process.
Step-by-step explanation:
The process that happens inside a cell that does not normally require consumption of free energy by the cell is C. Diffusion of small molecules within the cell. Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration, and it does not require cellular energy because it is a spontaneous process. In contrast, processes like replication of the genetic material, import of nutrients from the environment, regulation of gene expression, and synthesis of enzymes that catalyze cellular reactions are all energy-dependent processes.
The process mentioned in option C, "Diffusion of small molecules within the cell," is one that does not require the consumption of free energy by the cell. Diffusion is a passive, spontaneous movement of particles from areas of higher concentration to areas of lower concentration, driven by the inherent kinetic energy of the particles. This process allows small molecules to distribute themselves evenly within the cell without the need for cellular energy input.
In contrast, various cellular processes, such as the replication of genetic material, nutrient import from the environment, gene expression regulation, and enzyme synthesis, are energy-dependent and necessitate the consumption of free energy by the cell. These energy-driven processes are crucial for the maintenance, growth, and functioning of the cell, highlighting the distinction between energy-independent processes like diffusion and those that actively require cellular energy.