Mutations and Cancer SNC1P1

What is a Mutation? A mutation: is a permanent change is a cell’s DNA Most mutations occur during interphase (the S phase) when the DNA is duplicated. Most mutations do not actually affect the cell. Only a small percentage can lead to diseases like cancer.

How long do cells live for? Cell death is a normal part of life as long as it is regulated and controlled. o Example: cells produced to fight infections die when they are no longer needed. However, a mutation that affects a cell’s response during cell division or cell death can result in the development of cancer

So What is Cancer? Cancer is overactive mitosis (too much cell division too fast), which can lead to the formation of a tumor. The cells in our body need to reproduce through division, but when cell division gets out of control it starts causing problems.

Cancer Cells Video Clip ANxFVXKc

What are Tumors? An abnormal growth of tissue resulting from uncontrolled, multiplication of cells and serving no biological function.

Types of Tumours (1) Benign : o Cell division is unchecked and proceeds at a moderate rate o tumour cells remain at their original site and do not spread or invade other cells o Relatively harmless

Types of Tumours (2)Malignant : o Cell division is unchecked and occurs very quickly o Tumour cells send out signals to produce new blood vessels at the tumour site o Cells invade, damage, and destroy surrounding cells o Cells can break away from the tumour and escape spreading to surrounding tissues (via the bloodstream or lymph) and start new tumours = metastasis.

Malignant Tumor

Malignant Cancer Cell Video Clip

Unusual Features of Cancer Cells Cancer cells are immortal, whereas normal cells divide about 50 times and then they die Cancer cells often have unusual numbers of chromosomes or mutations in chromosomes. Cancer cells also have an abnormal cell surface ; instead of "sticking" to its neighbouring cells, cancer calls tend to "round up" and break attachments, allowing for metastasis. A=asymmetry B=borders are irregular C=color D=diameter

Carcinogens Carcinogens: are any substance or energy that causes a mutation in DNA. There are four types of known carcinogens 1. Viruses – Ex. leukemia – cancer of the white blood cells. 2. Radiation – UV rays, nuclear radiation. 3. Hazardous chemicals – toxic chemicals, chemicals found in cigarettes. 4. Free radicals – Ex. - can damage DNA and cause mutations as well.

Carcinogens Damage DNA

A Summary: Comparing Normal Cells to Cancer Cells Normal Cells - Make exact copies of themselves through mitosis - Reproduce for about divisions - Stick together to form masses of cells as appropriate - Self destruct when too old or too damaged Cancer Cells - Make exact copies of themselves through mitosis - Do not stop reproducing “Immortal” - Do not stick together - Behave independently - Abnormal borders, shape and color - May move to another location of the body. - Often have unusual numbers of chromosomes or mutations.

Comparing Normal Cells to Cancer Cells

Cancer Cells Normal Cells

Cancer Treatments 3D Medical Animation: Cancer Treatments _bI&feature=youtu.be _bI&feature=youtu.be 1) Chemotherapy 2) Radiation 3) Surgical Removal