Apoptosis Pathways Quiz

What are the two ways of apoptosis initiation?

• Extrinsic Pathway and Intrinsic Pathway

• Exogenous Pathway and Internal Pathway

• External Pathway and Inborn Pathway

• Extraneous Pathway and Innate Pathway

Which proteins are involved in the death signals for apoptosis?

• Tumor necrosis factor and CD95/Fas

• Interleukin-6 and Interferon-gamma

• Epidermal growth factor and Vascular endothelial growth factor

• Insulin-like growth factor and Platelet-derived growth factor

What is the function of procaspase-8 in apoptosis?

• It acts as an initiator caspase

• It stimulates calcium release from mitochondria

• It promotes the production of active caspase-9

• It activates the executioner caspase

Which protein is responsible for counteracting pro-apoptotic proteins in the outer mitochondrial membrane?

• Procaspase-9

• Bad

• Bcl-2

• Cytochrome c

What triggers the release of cytochrome c into the cytosol in the intrinsic pathway of apoptosis?

• Binding of survival factors

• Accumulation of pro-apoptotic proteins

• Activation of initiator procaspase

• Stimulation of calcium release from mitochondria

What is the role of cytochrome c in the intrinsic pathway of apoptosis?

• It activates the executioner caspase, caspase-3

• It binds to IP3 receptors and stimulates calcium release from mitochondria and ER

• It forms a complex with other proteins, resulting in activation of an initiator caspase

• It recruits a cytosolic adaptor protein that assembles procaspase-9 into an apoptosome

What is the function of caspase-9 in the intrinsic pathway of apoptosis?

• It recruits a cytosolic adaptor protein that assembles procaspase-9 into an apoptosome

• It forms a complex with other proteins, resulting in activation of an initiator caspase

• It promotes the production of active caspase-9

• It activates the executioner caspase, caspase-3

What is the role of p53 protein in inducing apoptosis?

• It activates the executioner caspase, caspase-3

• It can lead to apoptosis through DNA damage

• It promotes the production of active caspase-9

• It activates an initiator procaspase, procaspase-9

What initiates the extrinsic pathway of apoptosis?

• Accumulation of pro-apoptotic proteins leading to the formation of channels in the outer mitochondrial membrane

• Withdrawal of survival factors

• Binding of a tumor necrosis factor (TNF) family ligand to its receptor

• Cellular stress causing BH3 activation and cytochrome c release

What activates the effector caspase-3 in both extrinsic and intrinsic apoptosis pathways?

• Activation of initiator procaspase in the intrinsic pathway and binding of a death receptor in the extrinsic pathway

• Formation of channels in the outer mitochondrial membrane in the intrinsic pathway and clustering of receptors in the extrinsic pathway

• Downstream signaling proteins in the extrinsic pathway and cytochrome c release in the intrinsic pathway

• Binding of survival factors in the intrinsic pathway and withdrawal of survival factors in the extrinsic pathway