Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
|
Prophase
|
-lamins A,B,C are phosophorylated ="nuclear dissolution"
|
|
|
G0
|
cell is not actively engaged in division
-"quiescent period" -cell can be differentiated |
|
|
G1
|
- 9 hours long, most variable in time
- need growth factors - early and late response genes - sensitive to amino acid deprivation (protein synthesis) -cell synchrony |
|
|
What experiment did Arthur Pardee do?
|
- took 3T3 mouse cells
-found that you need growth factors (PDGF, EGF, insulin) to move on through cell cycle |
|
|
What happens when you add protein synthesis inhibitors to the G1 phase?
|
No late response genes
-need degradation of early response genes -late and early response genes are linked to each other |
|
|
What is cell synchrony? What happens?
|
Cell are synchronized according to the phase and the things available/present at the cell.
|
|
|
Amino acid deprivation will stop...
|
the G1 phase
|
|
|
Reversible DNA synthesis inhibitors block...
|
at the S phase
|
|
|
Protein synthesis inhibitors stops...
|
the G1 phase
|
|
|
Microtubule inhibitors blocks...
|
the M phase
|
|
|
Heat stops...
|
the M phase
|
|
|
What are restriction points? Where is it?
|
points beyond which cells are COMMITTED to divide. At G1 (unique only to G1)
|
|
|
What is required for G1 passage? How do you know?
|
cyclin D; use of BRDU (like 3H-thymidine, but NOT radioactive)
|
|
|
What are checkpoints?
|
-checks the fidelity of the phase's activity
-occurs at every juncture |
|
|
S phase
|
-DNA doubles
|
|
|
Explain the fiber autoradiography experiment. What did it discover.
|
take cell in S phase --+ 3H-thymidine--> take out DNA --> autoradiography --> see pattern that tells us DNA synthesis is occuring in BOTH directions and there are multiple origins ("replicons")
|
|
|
M phase
|
Prophase, Metaphase, Anaphase, telophase (PMAT)
- shortest in time (30 mins) - need MPF and cyclin B |
|
|
What triggers or regulates mitosis? How do you know?
|
- maturation promoting factor (meiotic cells) = MPF = mitosis phase factor (somatic cells) (induces a mitotic spindle)
- cyclin B -protein synthesis - X. laevis |
|
|
What is the cell free cell cycling experiment and what did it show?
|
Take X. laveus, frog sperm nuclei, cytoplasm and ATP into test tube --time--> mitosis occurs
- now cell free system can manipulate the system -protein synthesis and mRNA cyclin B is required for M phase |
|
|
What is the relationship between cyclin B and MPF?
|
MPF consists of cyclin B and CDK (cyclin dependent kinase)
|
|
|
What does ubiquitin need and why?
|
Cyclin B --> triggers hydrolysis of cyclin B --> MPF is no longer active
|
|
|
What is yeast important in? Types of yeast?
|
cell cycle regulation
-S. cervisae - budding yeast - S. pombe - fission yeast |
|
|
What is p53?
|
-tumor suppressor gene
-triggered by ATMR (detects damarage --> phosphorylated p53 --> stabilizes p53) -triggers p21 --> blocks cyclins -"guardian of the genome" - causes cells to die (apoptosis) if a lot of errors with cell or fixes the problem |
|
|
What happens when p53 is defective?
|
- seen in about 50% cencers
-can't commit radiated cells to apoptosis |
|
|
What was Ruth Sager's experiment?
|
took normal and cancer cells --> hybridoma --> cell division (genes are lost, p53 is lost) --> cancer cell
|
|
|
Who were the first two people to look at the cell cycle?
|
1953 - Howard and Pelc
|
