The activation of caspases is likely to lead to? & x20; - SJH Nursing Officer - 2019

SJH Nursing Officer - 2019

Biochemistry and Nutrition

Easy

Appeared in: SJH Nursing Officer - 2019

Explanation

Caspases are the central executioner enzymes responsible for carrying out apoptosis, which is the process of programmed cell death.
The name 'caspase' stands for Cysteine-ASPartic proteASE, highlighting their mechanism: they are proteases that use a cysteine residue in their active site to cleave target proteins specifically after an aspartic acid residue.
Apoptosis proceeds via a cascade where initiator caspases (like caspase-8 and -9) are activated by pro-apoptotic signals, and they, in turn, activate executioner caspases (like caspase-3).
Executioner caspases are responsible for dismantling the cell by cleaving key structural and regulatory proteins, leading to the morphological changes of apoptosis.

Option B: Blood coagulation is a distinct physiological process that stops bleeding. It is driven by the coagulation cascade, a series of enzymatic activations involving clotting factors (e.g., thrombin, fibrinogen), and is unrelated to caspases.
Option C: Mitotic cell division is the process by which a cell divides into two daughter cells. This process is tightly controlled by cyclins and cyclin-dependent kinases (CDKs), not caspases. In fact, apoptosis and cell division are generally opposing processes.
Option D: The G1 and S phases are parts of the cell cycle leading up to division. Progression through these checkpoints is regulated by specific cyclin-CDK complexes (e.g., Cyclin D-CDK4/6 for G1, Cyclin E-CDK2 for the G1/S transition), not by caspases.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Role of caspases in programmed cell death (apoptosis) as background academic context rather than a clinical decision trigger.
Understanding apoptosis is crucial as its dysregulation is implicated in many diseases. Insufficient apoptosis can lead to cancer (as malignant cells evade death) and autoimmune diseases (as self-reactive immune cells are not eliminated).
Excessive apoptosis contributes to tissue damage in conditions like myocardial infarction, stroke, and neurodegenerative diseases (e.g., Alzheimer's, Parkinson's).
Many chemotherapy drugs for cancer work by inducing apoptosis in rapidly dividing tumor cells.

How to Approach the Question

First, identify the key term in the question: 'caspases'.
Access your foundational knowledge of cell biology. Recall that caspases are a family of enzymes with a very specific and well-known function.
Connect the term 'caspase' to its primary role. The name itself is a mnemonic for its function in programmed cell death (apoptosis).
Evaluate the options based on this core knowledge. 'Apoptotic cell death' is the direct outcome of caspase activation.
Briefly consider the other options to confirm they are incorrect. Recognize that blood coagulation, mitosis, and cell cycle progression are regulated by entirely different molecular pathways (clotting factors, cyclins, CDKs), making them incorrect choices.

Concept Tested & Keywords

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