Transcript Cell Cycle and Mitosis

Cell Cycle and Mitosis
Organization of the process of cell
division!
“Omnis cellula e cellula”
Rudolf Virchow
1855
Types of Cell Division
• Binary Fission
– Prokaryotic Cell
Division
• Mitosis
– Eukaryotic Cell
Division
• Meiosis
– Production of sex cells
Do all cells divide?
• Cells that divide
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Stem Cells
Glial cells in the brain
Skin cells
Cancer cells
• Cells that don’t really
divide (senescence)
– Red Blood Cells
– Neurons
– Heart Cells
Why might a cell need to divide?
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Embryonic Development
Repair Tissues
Cells have a max surface area to volume ratio
Asexual reproduction
Cancer
Cell Cycle in Eukaryotes
What is the meaning of mitosis?
• Interphase
• Mitosis
• Cytokinesis
How is the genetic material
organized
How does the cell change during
the cell cycle?
• Are the stages
discreet or
continuous?
• What is important
about metaphase?
How are changes in genetic
material detected?
• Changes in nuclear
material first detected by
dark stain of the nuclear
material = “Chromo”
• Advances in light
microscopy show role of
centrosomes, spindle
fibers, kinetochores
Phases of mitosis
• See pg 232
• Note activity of chromosomes, envelope,
spindle during each stage
• Chromosome “walking”
• Review: Biovisions video
What tells a cell to divide?
• External Controls
– Growth Factors
• Internal Controls
– Cyclins
– CDK
What proteins control cell growth
internally?
• CDK: always present in cells
• Cyclin: level varies throughout the cell cycle
• MPF: “mitosis promoting factor” --occurs when
cyclin binds to CDK.
How does
cyclin’s
structure allow
for its function
of promoting
mitosis?
Cancer
• Cancer is when the
cell cycle goes wrong.
• What might happen to
cause a cell cycle to
wreak havoc?