7.3 Cell Cycle Dysregulation and Apoptosis Flashcards
What is the definition of cell proliferation?
process of cell growth that is fundamentally necessary for the development and tissue repair in multicellular organisms
Which cells undergo cell proliferation under normal circumstances?
lining of the skin, intestines and bone marrow cells
What are differentiated cells?
cells that have matured to provide a specific function
What is a generic characteristic of differentiated cells?
they remain quiescent unless stimulated to divide
Which differentiated cells always divide?
epithelial cells
GI cells
immune system cells
What are the phases of the cell cycle?
interphase
mitosis
G0
What are the phases in interphase?
G1 S G2
What occurs during G1 phase?
cell is stockpiling enzymes and molecules for DNA replication
What occurs during S phase?
chromosomal DNA is actively being replicated
What is interphase?
cell is replicating DNA and performing normal functions
What is G2 phase?
cell is growing and checking to make sure it is ready for cell division
What occurs during M phase?
cell division
What are cells known as when they are in G0?
quiescent
What is the phase G0?
endpoint for most differentiated cells unless stimulated to enter the rest of the cell cycle
What cells cannot enter G0?
cancer cells
What does it mean that cancer cells have aberrant signal transduction pathways?
constantly and erroneously provided with growth signals or cannot respond to signals that tell the cell to stop dividing
How many cell cycle checkpoints are there?
three
What are checkpoints?
ensure that a normal cell progresses through the cell cycle as usual
Where are the three cell cycle checkpoints?
G1/S
G2/M
and in M
What is needed to pass the G1/S checkpoint?
cell must be adequate size
DNA needs to be undamaged
