Module 2 - Lesson 1 & 2 Flashcards
What is the role of mitochondria in apoptosis?
Mitochondria release cytochrome c which helps activate caspases.
What family of proteins regulates apoptosis through interactions with mitochondria?
The Bcl-2 family.
What type of caspase is initiator caspase-9 classified as?
Initiator caspase
Which protein forms the apoptosome?
Apaf-1
What type of cell death is typically associated with inflammation?
Necrosis
How do pro-apoptotic and anti-apoptotic Bcl-2 family members affect apoptosis?
Pro-apoptotic members promote mitochondrial membrane permeabilization, while anti-apoptotic members inhibit it, thus regulating cytochrome c release and caspase activation.
Why is caspase activation a key step in apoptosis?
Caspases cleave various cellular substrates, leading to the systematic dismantling of the cell.
How does the intrinsic pathway of apoptosis differ from the extrinsic pathway?
The intrinsic pathway is initiated by internal signals like DNA damage and involves mitochondrial cytochrome c release, while the extrinsic pathway is triggered by external death ligands binding to cell surface receptors.
Why is the apoptosome important in programmed cell death?
It brings together Apaf-1 and procaspase-9 to initiate the caspase cascade.
What would happen if a cell overexpressed anti-apoptotic Bcl-2 proteins?
The cell would be resistant to apoptosis, potentially leading to uncontrolled cell growth or cancer.
How can you experimentally detect activation of caspase-3 in apoptotic cells?
Use antibodies specific to the cleaved (active) form of caspase-3 in Western blotting or immunofluorescence.
If a researcher knocks out the gene encoding Apaf-1, what is the expected outcome in response to mitochondrial damage?
Apoptosis would be impaired due to failure to form the apoptosome.
Describe a method to determine whether a cell is undergoing intrinsic versus extrinsic apoptosis.
Use assays to detect cytochrome c release (intrinsic) versus Fas receptor activation or caspase-8 activation (extrinsic).
