Apoptosis and FACS Analysis Quiz

A programmed process of cell death that is essential for normal development and tissue homeostasis.

Uncontrolled cell death caused by injury, toxins, or lack of oxygen, leading to inflammation and tissue damage.

A self-eating process where cells break down and recycle their own components, providing nutrients and energy under stress.

A pathway triggered by internal cellular stress, such as DNA damage or lack of nutrients, leading to activation of caspase enzymes.

A pathway triggered by external signals, such as death ligands from other cells, activating receptor proteins and initiating caspase cascade.

A family of proteases responsible for dismantling the cell during apoptosis, breaking down proteins and leading to cell fragmentation.

Proteins that promote apoptosis, such as Bax, Bak, and Bid, which activate caspases to trigger cell death.

Proteins that inhibit apoptosis, such as Bcl-2 and Bcl-xL, preventing caspase activation and protecting cells from death.

Organelles formed by the fusion of lysosomes and phagosomes. They degrade components of engulfed materials and recycle usable parts for the cell.

The breakdown or degradation of chromatin within a cell, often associated with cell death.

External signals that trigger intracellular pathways, activating enzymes that lead to programmed cell death.

Signals that trigger cell death pathways are external and originate from the environment. These signals interact with receptors on the cell surface, initiating the process of cell death.

A series of steps or reactions within a cell that are triggered by external signals. These pathways can lead to cell death.

Proteins that act as catalysts, speeding up chemical reactions in cells. They play a role in cell death by breaking down cell structures.

Specific signals are critical for cell death because they ensure that only unwanted or damaged cells are eliminated, while healthy cells remain unaffected. This controlled process prevents uncontrolled cell death and maintains tissue homeostasis.

An orderly and controlled process of cell suicide, essential for development, tissue maintenance, and eliminating damaged cells.

Annexin V-FITC is a fluorescent dye that binds to phosphatidylserine (PS), a phospholipid that flips to the outer leaflet of the cell membrane during apoptosis.

PI is a fluorescent dye that can enter cells with damaged membranes, which is characteristic of late-stage apoptosis or necrosis.

A FACS plot displays cell populations based on their fluorescent signals. Cells stained with Annexin V-FITC and PI are categorized into quadrants: Live, Early Apoptosis, Late Apoptosis, and Necrosis.

A chemotherapy drug might induce apoptosis in cancer cells. Analyzing changes in Annexin V and PI staining patterns after treatment can show how effective the drug is at killing cancer cells.

Fas ligand binds to its receptor, initiating the extrinsic apoptosis pathway. This binding triggers a cascade of events leading to cell death.

The DISC (Death-Inducing Signaling Complex) forms when Fas ligand binds to its receptor. This complex activates caspase 8, a key protein in the apoptotic cascade.

Pro-caspase 9 is an inactive precursor of the caspase 9 enzyme. Cleavage of pro-caspase 9 into active caspase 9 is essential for the intrinsic apoptotic pathway.

The apoptosome is a complex formed during the intrinsic apoptosis pathway. It is crucial for activating caspase 9, which initiates a cascade leading to cell death.

Overexpression of Bcl-2, an anti-apoptotic protein, can lead to cancer. Bcl-2 inhibits apoptosis by preventing the release of cytochrome c from mitochondria.

A type of phospholipid found in the inner leaflet of the cell membrane. During apoptosis, PS translocates to the outer leaflet, which serves as a signal for phagocytosis by macrophages, a process where these cells engulf and remove the dead cell.

A protein that binds to phosphatidylserine (PS). Used in conjunction with fluorescent dyes, Annexin V can be used to detect apoptotic cells via flow cytometry. When Annexin V binds to PS on the cell surface, it reveals a green signal under a fluorescent microscope.

A fluorescent dye that is used to detect necrotic cells. PI can only enter cells with damaged membranes, which occurs during necrosis. It binds to DNA and emits red fluorescence, allowing scientists to identify necrotic cells under a microscope.

A technique used to analyze and sort cells based on their properties, such as size, granularity, and protein expression. Flow cytometry is a valuable tool for studying apoptosis as it can identify cells with different apoptotic stages based on their protein expression and membrane permeability. Cells are stained with fluorescent dyes, and then passed through a laser beam. The light scatter pattern and fluorescence intensity of each cell provide information about its characteristics.

A graph that shows the results of flow cytometry data. Cells are plotted according to two parameters, usually fluorescent intensity of two different dyes (e.g., Annexin V and Propidium Iodide). The plot helps visualize the distribution of cells with different apoptotic states.

A protein that inhibits the release of cytochrome c from mitochondria, preventing caspase activation and apoptosis. Mutations in Bcl-2 can allow damaged cells to survive.

A protein that promotes the release of cytochrome c from mitochondria, leading to caspase activation and apoptosis. Mutations in Bax can impair apoptosis.

A protein that activates Bax, promoting apoptosis. Mutations in Bim can prevent apoptosis.

A protein that activates caspase 9, initiating the apoptotic cascade. Mutations in cytochrome c can contribute to cancer.

A protein involved in the extrinsic apoptotic pathway that binds to its receptor, triggering apoptosis. Mutations in FAS ligand can prevent the binding process.

A protein that inhibits caspases, preventing apoptosis. Mutations in IAP can contribute to cancer.

A protein that promotes cell cycle arrest or apoptosis in response to DNA damage. Mutations in p53 can lead to cancer.