Cell proliferation Flashcards
what is needed for cells to proliferate?
An appropriate extracellular signal.
what is the signal that tells the cell to proliferate?
A mitogen.
how does this signal allow the cell to proliferate?
the mitogen signal allows the cell to pass the R point which is located at the end of G1.
What are the different signals a cell can get?
what is the R point?
this is the restriction point or the cellular brake of the cell cycle as it stops cells from advancing and it is applied to cells that are not proliferating.
how do mitogens transmits the signal to the cell?
via a receptor found on the cell membrane which as a result become phosphorylated (activated) and relay signals via an intracellular signalling cascade which activates transcription factors.
What is EGF?
Epidermal Growth Factor, whch controls growth of epithelial cells.
EGF signalling is disrupted in many cancers.
Describe the phases of the cell cycle?
G1 - cell assimilation and growth
S - chromosome replication
G2 - checking
M - distribution of chromosomes
C- cytokinesis
Interphase + M phase
What is the G0 phase?
A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.
what does MAPK stand for?
mitogen activated protein kinase pathway
what else happens in G1 phase?
loading of inactive helicases onto replication origins by pre-RCs (multiple proteins)
Describe what is happening here.
Injected cytoplasm from mitotic cells into the oocyte. This causes the nucleus to break down and you would be able to observe the spindle fibre, hence it is going through mitosis.
However injecting cytoplasm from a n interphase cell, does not affect the nucleus of the oocyte.
