1. Active Transport: This process moves molecules across a cell membrane against their concentration gradient, meaning from an area of low concentration to an area of high concentration. This requires energy because it's like pushing a rock uphill. Examples include the sodium-potassium pump, which is crucial for nerve impulses and muscle contractions.

2. Protein Synthesis: The process of building proteins from amino acids requires energy. This includes the steps of transcription (copying DNA into RNA) and translation (using the RNA to assemble amino acids into a protein). Protein synthesis is vital for everything from building cell structures to producing enzymes that catalyze reactions.