Module 3: Lesson 7 Flashcards
(21 cards)
What are the four phases of the eukaryotic cell cycle?
M, G1, S, and G2.
What are the two processes of the M phase?
Mitosis and cytokinesis.
What are the sub-phases of mitosis?
Prophase, prometaphase, metaphase, anaphase, and telophase.
What is cytokinesis?
Cytoplasmic division when the cell divides itself into two.
What is interphase?
The period between one M phase and the next. It contains phases G1, S, and G2.
What happens in G1 Phase?
Cell monitors its internal state and the extracellular environment, gene transcription, protein synthesis, cell growth, and DNA repair. It takes 1-2 hours.
If conditions are favorable and signals to grow and divide are present, cells progress through a commitment point near the end of G1 known as the restriction point.
What happens in G0 Phase?
When conditions are not favorable at the end of G1 Phase, progress is delayed and the cell rests in G0.
What is terminal differentiation?
Complete withdrawal from the cell cycle. Dismantle cell cycle control system.
What is senescence?
Removal from cell cycle, loss of ability to divide and grow but still alive and metabolically active; will not re-enter the cell cycle.
What is quiescence?
A state of reversible growth arrest in which cells have exited the cell cycle but remain capable of re-entry upon stimulation.
What happens in S Phase?
The DNA of the chromosomes are duplicated (but no chromosome separation); replication of centrosomes, but not separation. It takes 10-12 hours.
What happens in G2 Phase?
Growth, protein and lipid synthesis, monitoring the internal and external environments continue; final preparations to enter the M phase (cell checks for size, DNA replication and DNA damage).
What are the main checkpoints in the cell cycle?
G1 checkpoint, G2/M checkpoint, and checkpoint in mitosis.
What does the cell cycle control system depend on?
Cyclically-dependent protein kinases (Cdks), which are only active when bound to cyclin. Cdk is present throughout the cycle and activated at appropriate times throughout it.
What is anaphase promoting complex (APC)?
A large enzyme that assists in the degeneration of M and S cyclins during the M phase. It catalyzes the ubiquitylation of S- and M- cyclins.
What is required for M-Cdk to activate?
As soon as the M-Cdk complex is formed, it is phosphorylated at two adjacent sites by an inhibitory protein kinase called Wee1.
What are mitogens?
Growth factors/signals that grow and divide the cell during M phase.
The activation of the MAPK pathway leads to increased production of gene regulatory proteins that activate gene expression of cyclins.
What does G1-Cdk do?
Release inhibitors of gene transcription that produce S phase cyclins.
How is progress through G1 halted?
Via DNA damage. Concentration and expression of p53, a tumor suppressor gene, accumulates.
What are the physical and chemical properties of flow cytometry?
Physical: size and granularity.
Chemical: fluorescent tags = antibodies or genetic reporter.
What is the combination of three systems in flow cytometry?
Microfluidics, optics/lights, and electronics.
