Cells must use energy to move a substance against a concentration gradient (i. e., from a compartment with a low concentration of the substance to a compartment with a higher concentration). which of the following processes would require a cell to expend energy? choose all of the correct answers. transport of sodium ions out of cells transport of sodium ions into cells transport of potassium ions out of cells transport of potassium ions into cells transport of calcium ions out of cells transport of calcium ions into the cytoplasm of a cell from the ecf transport of calcium ions out of the cytoplasm of a cell and into an organelle that has a high concentration of calcium ions. transport of calcium ions out of an organelle that has a high concentration of calcium ions and into the cytoplasm of a cell.