Mitosis, Mutations, and Cancer

General Cancer Definition

loss of cell cycle control causing unregulated cell division

What is the common cause of cancer?

genetic mutations

Where do you typically find the start of mutations?

genes on chromosomes 

Why do cells divide?

• reproduction

• development

• replacing other cells

• healing wounds

What are the phases of the cell cycle?

• mitosis

• G0

• G1

• checkpoint

• synthesis

• G2

What happens during mitosis?

cell divides actively

What happens during G0?

resting phase (gap)

What happens during G1?

makes extra cell components (gets bigger)

What happens during checkpoints?

quality check for cell size and contents

What happens during synthesis?

dna replication

What happens during G2?

quality control for dna (last change to check before division)*

what are the chromosomal phases? 

• interphase

• prophase

• metaphase

• anaphase

• telophase

• cytokinesis

What phases are in Interphase?

• G1

• S

• G2

What does the cell look like in interphase? 

almost normal (chromosomes loosely gathered in the nucleus but not yet condensed) 

What does the cell look like in prophase?

chromosomes get coiled up (get condensed)

What does the cell look like in metaphase?

chromosomes align in the middle of the cell

What does the cell look like in anaphase?

microtubules separate the sister chromatids

What does the cell look like during telophase?

the separated chromatids move to opposite ends of the cell and two nuclei are formed

What does the cell look like during cytokinesis?

cytoplasm divides and daughter cells are formed

What are chromatids/ sister chromatids?

one of two identical strands of a duplicated chromosome

Homologous Chromosomes

chromosomes of different origin that are the same size, shape, and have genes in the same order

Inhibition

the process of stoping or slowing down cell division

Proto-Oncogenes

accelerators - promote cell division

Tumor Suppressor

breaks - checks by stopping the process of division

Point Mutations

One nucleotide gets replaced for another

Frameshift Mutations

change in the reading frame of a gene

Metastasis

the spread of cancer cells from og spot to other parts of the body

Benign Tumor

noncancerous tumor

Malignant Tumor

cancerous tumor with cells that can spread over the body

What happens during radiation therapy?

directly targets cancerous tissue damaging DNA and harming the cells

What happens during chemotherapy?

drugs interfere with a specific step of the cell cycle so that it fails causing the cell to undergo apoptosis