Ch.14 Flashcards
2 types of cell deaths
Program
Injury
Cell death and cell proliferation are balanced throughout the life of?
Multicellular organisms
Why programmed cell death?
- Balance prolifiration
- Eliminate damage cells
- Eliminate virus infected cells
Apoptosis
An active process of programmed cell death, characterized by: Cleavage of chromosomal DNA Chromatin condensation Fragmentation of the nucleus Fragmentation of the cell
How do you stop the transcription if you want to kill the cell?
By killing chromosomal DNA
Phagocytosis
Cell eating is the ingestion of large particles such as bacteria.
During phagocytosis, cells engulf large particles such as bacteria, cell debris, or other intact cells.
3 types of gene required for apoptosis:
Ced-3, ced-4, and ced-9
Caspases
Are protease and are the ultimate affectors or executioners of programmed cell death, bringing about the events of apoptosis by cleaving nearly 100 different cell target proteins.
All Caspase are synthesized as inactive precursors that can be converted to the active form by….
Proteolytic cleavage
Who controls caspase activation(cleavage)?
Other Caspase
Apootosome
Is a protein complex in which Caspase-9 is activated to initiate apoptosis following the release of cytochrome c from mitocondria.
Ced-9
An oncogene inhibiting apoptosis
Ced-3
Caspase
Ced-4
Apaf-1
3 functional groups of bcl-2?
- antiapoptotic-bcl-2 protein(ced-9)
- proapoptotic- multidomain
- proapoptotic- BH3 only (Noxa, puma)
Cell’s death or life depends on..
Proapoptotic and antiapoptotic of bcl-2 family
P53
Is a transcription factor that arrests the cell cycle in G1 in response to damaged DNA and is required for apoptosis induced by a variety of stimuli.
Role of p53 in DNA damage-induced apoptosis
- Hold cell cycle to allow cell to repair damage
2. It can transcribe puma/Noxa members to BCR family.
Tumor necrosis factor (TNF)
Polypeptide growth factor that induced programmed cell death
How do cell death receptor signal apoptosis?
By directly activating an initiator Caspase
What happens during apoptosis?
DNA fragmentation, chromatin condensation, fragmentation of nucleus,fragmentation of cell.
Most cells in adult animals are arrested in which stage?
G0
What is stem cell?
- Found in all multi-cellular organisms
- they retain the ability to renew themselves through mitotic cell division and can differentiate into a diverse range of specializing cell types.
What are the unique properties of stem cells?
- capable of dividing and renewing themselves for long periods
- they are unspecialized
- they can give rise to specialized cell types
Embryonic stem cells (ES cells):
- Stem cells derived from the inner cell mass of an early stage embryo
- able to differentiate into all types of cells in the adult body.
- more specialized
- can make every part of your body
Adult stem cells
Undifferentiated cells found throughout the body after embryonic development that divide to replenish dying cells and regenerate damaged tissues.
What are the similarities and differences between embryonic and adult stem cells?
Adult and embryonic stem cell differ in the number and type of differentiated cell typed they can become
- ES cells can become all cell types of body because they are pluripotent
- adult stem cells are generally limited to differentiating into different cell types of their tissue of origin.
- adult stem cell plasticity may exist, increasing the number of cell types a given adult stem cell can become.
Totipotent
Cell has the potential to divide an produce all the differentiated cells in an organism, including extraembryonic tissues.
Pluripotent
Stem cells can give rise to any fetal or adult cell type. However, alone they can not develop into a fetal or adult animal because they lack the potential to contribute to extraembryonic tissue, such as the placenta.
Multipotent
Cell can give rise to several other cell types, but those typed are limited in number.
Ex: hematopoietic
Progenitor
Cells are refer to immature or undifferentiated cells, the term Is far less restrictive.
Plasticity
Ability of stem cells from one tissue be able to differentiate into cells give rise to other tissues.
A bone marrow transplantation is..
A clinical procedure in which transplantation of bone marrow stem cells is used in the treatment of cancer and disease of hematopoietic system.
Epithelial stem cells
Clinical application in the form of skin grafts that are used to treat patients with burn, wound, and ulcers
Somatic cell nuclear transfer
Basic procedure of animal cloning in which the nucleus of an adult somatic cell is transferred to an enucleated egg
Primary goal of stem cell research is..
To identify how undifferentiated stem cells become differentiated. Turning genes is central role to this process.
Direct cell conversion
Transdifferentiation(does not involve stem cell)
