Q.29 Which of the following cell organelle(s) is/are surrounded by a single
phospholipid membrane?
(A) Golgi apparatus
(B) Lysosome
(C) Mitochondria
(D) Nucleus

Lysosomes are the cell organelle surrounded by a single phospholipid membrane among the given options. This structure helps them function as the cell’s digestive system by containing hydrolytic enzymes safely isolated from the cytoplasm.

Correct Answer

(B) Lysosome​

Option Breakdown

• Golgi apparatus: Consists of stacked cisternae, each enclosed by a single membrane, but the organelle as a whole features multiple such membranes rather than a singular enclosing one.​

• Lysosome: Bounded by a single phospholipid bilayer that sequesters powerful digestive enzymes, preventing damage to other cellular components.​

• Mitochondria: Possesses a double membrane—an outer porous layer and an inner folded cristae membrane for ATP production.​

• Nucleus: Enveloped by a double nuclear membrane perforated with pores for material exchange between nucleoplasm and cytoplasm.​

Biological Relevance

Single-membrane organelles like lysosomes enable targeted degradation of waste, pathogens, and damaged parts, maintaining cellular homeostasis. In contrast, double-membrane structures such as mitochondria and nuclei support specialized functions like energy generation and genetic control. Understanding these distinctions is key for exams in cell biology and biochemistry.