Cell Proliferation and Mitosis Flashcards
What is proliferation?
Physiological process of cell division
Results in an increased number of cells
Occurs in almost every tissue
What causes rate of proliferation to decrease
Cell differentiation
Cell that are unable to proliferate
Cardiac myocytes
Neurons
Cells that can resume proliferation from G0
Skin fibroblasts, smooth muscle cells, epithelial cells of internal organs
Cell that undergo continual proliferation
Blood cells, skin epithelial cells
Factors that contribute to and regulate proliferation
Environmental - nutrients, temperature, pH, oxygen
Positive and negative - cell adhesion, growth factors
Intracellular - p53, cytochrome C, Bcl proteins
What is the purpose of germ cell
Give rise to the gametes
Make it possible for organisms to reproduce
Meiosis and Mitosis
What are somatic cells
Give rise to all cell in the body apart from gametes
Cells are differentiated
Mitosis
What are the two main phases of cell cycle
S-phase: DNA synthesis
M-phase: Nuclear division, cytoplasmic division
What are the four phases of the cell cycle
G1 phase
S-phase
G2 phase
M-phase
What is the purpose of gap phases
Allow cell to grow
Monitor internal and external conditions
What is the purpose of G1 checkpoint
Makes sure the cell is large enough to enter S-phase
If conditions unfavourable - can enter G0
What is the purpose of G1 checkpoint
Makes sure the cell is large enough to enter S-phase
If conditions unfavourable - can enter G0
What is the point of G2 checkpoint
Makes sure the cell has been completely replicated
replication errors have been corrected
the cell is large enough the divide
How is cell cycle contolled
Fixed amount of time for each event
information from the cell cycle events and external environment (cyclins and CDKs)