Controls of the Cell Cycle

Controls of the Cell Cycle

Internal ExternalExternalChemical Chemical PhysicalPhysical

Ex. At M phase checkpoint

Chemical signals

essential nutrientgrowth factors

1. Density-dependent inhibition

• crowded cells stop dividing

Cells must be attached to a substratum

ex. inside of a culture jar or ECMof a tissue

Don’t respond to body’s control mechanisms

Divide excessively

Don’t exhibit density-dependent inhibition

“Immortal”

HeLa cells

Diverse

Gene alteration

Worst 5 Foods

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HOW CANCER CELLS HOW CANCER CELLS SPREADSPREAD

Transformation (normal cell to cancer cell)

Tumor (mass of abnormal cells w/in normal tissue)

Benign tumor

Malignant tumor / cancer

Metastasis

How

Cancer

Cells

Spread

1. High-energy radiation

For localized tumor

Destroys DNA in cancer cells

2.Chemotherapy

For metastatic tumors

For actively dividing cells

Side effects

To summarize…To summarize…