Question

Which of the following labilisers found on the membrane of the lysosome?
A. Cortisone and cortisol
B. Cholesterol and heparin
C. Testosterone and progesterone
D. Cholesterol and progesterone

Answer 1

Hint: Lysosome is a membrane-bound organelle that is found on animal cells. It contains digestive enzymes that break down excess or worn-out cell parts. They are also used to destroy invading viruses and bacteria.

Complete Answer:
Labilisers cause instability of the lysosomal membrane, leading to the release of enzymes from the lysosome. Other substances, called stabilizers, have a stabilizing action on the membrane. Let us analyze each given option to find out the correct answer.

Option A: Cortisone and cortisol are stabilizers. They have a stabilizing action on the lysosomal membrane.
- Lysosomal membrane stabilization has been proposed as a mechanism for the anti-inflammatory action of corticosteroid hormones. Cortisone is a 21-carbon steroid hormone.
- It is one of the main hormones released by the adrenal gland in response to stress. It controls and regulates the release of the lysosomal enzymes into the cellular fluid. Therefore, this is an incorrect option.

Option B: Cholesterol and heparin is a lysosomal stabilizer. Heparin is an anticoagulant. Therefore, this is an incorrect option.

Option C: The dispersed spherical structures called lysosomes contain the hydrolysing enzyme which is incapable of digesting their own membrane because the membrane is highly modified.T he enzymes are rendered inactive by electrostatic binding forces.
- Lysosomal membranes are sensitive to many labilisers and stabilizers. Vitamins like A, B, K, and hormones like progesterone, B-estradiol, and some metal ions like silver, mercury, etc. labilize the membrane and allow the enzymes to diffuse out.
- But cholesterol, cortisones, etc stabilize the membranes. Thus, intracellular conditions control and regulate the release of the lysosomal enzymes into the cellular fluid. Therefore, this is the correct option.

Option D: Cholesterol is stabiliser while progesterone is labelizer. Progesterone labilize the membrane and allows the enzymes to diffuse out. However, cholesterol stabilizes the membranes, and thus, intracellular conditions control and regulate the release of the lysosomal enzymes into the cellular fluid. Therefore, this is an incorrect option.

Hence the correct answer is option C.

Note: It is to be noted that labiliser increases the permeability of the lysosomal membrane to small solutes like sucrose. Therefore, the osmotic swelling might completely disrupt the membrane.