Animal Cell Death Flashcards
Difference between Apoptosis and Necrosis
Apoptosis: Active, programmed process of autonomous cellular dismantling that avoids inflammation.
Membrane blebbing and then cell breaks apart into several apoptotic bodies which are then phagocytosed. No inflammation.
Necrosis: Passive, accidental cell death resulting from environmental perturbations with uncontrolled inflammation.
Cell swells and then plasma membrane ruptures. Cellular and nuclear lysis causes inflammation.
What are growth-linked products and nongrowth linked products.
Growth-linked products: Primary metabolites
Nongrowth linked products: Majority secondary products
Explain how exponential growth in batch culture may be prolonged
Through continuous culture, exponential growth may be prolonged by the addition of fresh medium to the vessel with an overflow device was fitted to the fermenter such that the added medium displaced an equal volume of culture from the vessel then continuous production of cells could be achieved.
If medium has been designed such that growth is substrate limited and not toxin limited.
Continuous Culture
If medium is fed continuously to such a culture at a suitable rate, a steady state is achieved eventually that is formation of new biomass by the culture is balanced by the loss of cells from the vessel.
If substrate is depleted below the level that supports the growth rate dictated by the dilution rate, the following sequence of events takes place?
1) The growth rate of the cells will be less than the dilution rate and they will be washed out of the vessel at a rate greater than they are being produced, resulting in decrease in biomass concentration.
2) The substrate concentration in the vessel will rise because fewer cells are left in the vessel to consume it.
3) The increased substrate concentration in the vessel will result in the cells growing at a rate greater than the dilution rate and biomass concentration will increase
4) The steady state will be reestablished.
