Which cell organelle contains the hydrolase enzyme cathepsin ?
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To remember the organelle with acid hydrolases: think "Lyse" = to break apart. Lysosomes contain over 40 types of hydrolytic enzymes, including proteases (cathepsins).
Step 1: Understanding the Concept:
Lysosomes are membrane-bound cellular organelles containing a variety of hydrolytic enzymes.
These enzymes, active under acidic conditions, degrade macromolecules, cellular debris, and foreign material. Step 2: Detailed Explanation:
Cathepsins are a large family of proteases (peptidases) that cleave peptide bonds in proteins.
They are classified based on their active site structure into cysteine proteases (e.g., cathepsins B, L, H), aspartic proteases (e.g., cathepsin D), and serine proteases (e.g., cathepsin G).
Most cathepsins are synthesized as inactive zymogens on ribosomes, transported through the rough endoplasmic reticulum and Golgi complex, and targeted to lysosomes via the mannose-6-phosphate receptor pathway.
Inside the lysosome, the internal acidic pH (maintained at approximately 5 to 0 by a proton-pumping vacuolar ATPase) promotes the auto-activation and optimal catalytic performance of cathepsins.
Thus, lysosomes are the default functional compartment for cathepsins. Step 3: Final Answer:
The lysosome is the cell organelle that contains the hydrolase enzyme cathepsin.
