Which of the following releases energy?
nutrients entering a cell through the cell membrane
removing a phosphate group from an atp molecule
building sugar or starch molecules for long-term energy storage
adding an additional phosphate group to an adp molecule

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.