Which term refers to membranes that enclose organelles within the cell?

• A. Plasma membranes
• B. Nuclear membranes
• C. Organelle membranes
• D. Cell wall

Answer: (C)

Membranes that enclose organelles within the cell are called organelle membranes. Inside the cell, many structures are surrounded by their own membranes, forming distinct compartments that keep enzymes and reactions localized and regulated. This organization lets each organelle maintain its own environment, such as the mitochondrial membrane supporting energy production or the nuclear envelope guarding genetic material. The plasma membrane, by contrast, surrounds the entire cell and is not the membrane that encloses individual organelles. The cell wall is a rigid layer outside the plasma membrane in plants and some microbes and is not a membrane around organelles.