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Mitosis and Cancer

I) The Cell Cycle

*Two stages: Dividing and a Non-dividing stage


A) Interphase

1) G1 Phase

*Variable in length

*synthesize cell membrane components

*unwind genetic material

2) S Phase

*replicate DNA

*synthesize proteins (histones & enzymes)

*synthesize microtubules

3) G2 Phase

*rewind DNA

*synthesize and store more proteins

B) Mitosis

1) Prophase

*Chromosomes become visible

*mitotic spindle forms

*nuclear membrane degrades and disappears

2) Metaphase

*Chromosomes align at the equatorial plane

3) Anaphase

*Chromosomes are pulled to opposite poles of cell

4) Telophase

*mitotic spindle disassembles

*nuclear membrane reforms




II) Control of Mitosis

A) Cellular Clock

* Apotosis

B) Density-dependent inhibition

C) Extracellular Influences

* Hormones and Growth Factors

D) Intracellular influences

* kinase and cyclin

E) Cell Population

III) Cancer

A) malignant vs. benign tumors

Malignant Benign

Not localized localized

Irregular regular/encapsulated

Metastasis No metastasis

Immediate health effect No immediate health effect

B) Characteristics of cancer cells

C) Causes of cancer

    1. Oncogenes
    1. Tumor Suppressors
    1. Carcinogens
    1. Direct carcinogen
    1. Procarcinogen
    1. Promoter

D) Decreasing the risk of cancer

    1. Prevention
    2. Diagnosis
    3. Treatment