Section 5-3 & 5-5 Cancer & Stem Cells Section 5-3 & 5-5 Cancer & Stem Cells Write everything that is underlined.

Section 5-3 & 5-5Section 5-3 & 5-5“Cancer & Stem “Cancer & Stem

CellsCells””

Write everything that isWrite everything that is underlinedunderlined

5.3 Cancer / 5.5 Stem Cells

5.35.3 KEY CONCEPT KEY CONCEPTCell cycle regulation is necessary for Cell cycle regulation is necessary for healthy growthhealthy growth

5.3 Cancer / 5.5 Stem Cells

I. Cell DivisionI. Cell Division1. Internal and external factors regulate 1. Internal and external factors regulate (control) cell division(control) cell division

a. External factors include physical and chemical a. External factors include physical and chemical signalssignals

b. Growth factors are proteins that stimulate cell b. Growth factors are proteins that stimulate cell divisiondivision– Most mammal cells form a single layer in a Most mammal cells form a single layer in a

culture dish and stop dividing once they culture dish and stop dividing once they touch other cellstouch other cells

5.3 Cancer / 5.5 Stem Cells

– a normal feature of healthy organismsa normal feature of healthy organisms

– caused by a cell’s production of self-caused by a cell’s production of self-destructive enzymesdestructive enzymes

– occurs inoccurs indevelopmentdevelopmentof infantsof infants

webbed fingers

2. Apoptosis is programmed cell death2. Apoptosis is programmed cell death

5.3 Cancer / 5.5 Stem Cells

II. Cancer CellsII. Cancer Cells 1. Cell division is uncontrolled in 1. Cell division is uncontrolled in cancercancer2. Cancer cells form disorganized 2. Cancer cells form disorganized

clumps called tumorsclumps called tumors

–BenignBenign (good) tumors remain (good) tumors remain clustered and can be removedclustered and can be removed

–MalignantMalignant (bad) tumors (bad) tumors metastasize, or break away, and metastasize, or break away, and can form more tumorscan form more tumors

5.3 Cancer / 5.5 Stem Cells

cancer cell bloodstreambloodstream

normal normal cellcell

5.3 Cancer / 5.5 Stem Cells

3. Cancer cells do not carry out their 3. Cancer cells do not carry out their necessary functionsnecessary functions

4. Cancer cells come from normal 4. Cancer cells come from normal cells with damage to genes cells with damage to genes involved in cell-cycle regulationinvolved in cell-cycle regulation

5.3 Cancer / 5.5 Stem Cells

5. Carcinogens are substances known to 5. Carcinogens are substances known to cause cancercause cancer

6. Standard cancer treatments typically kill 6. Standard cancer treatments typically kill both cancerous and healthy cellsboth cancerous and healthy cells

5.3 Cancer / 5.5 Stem Cells

5.55.5 KEY CONCEPT KEY CONCEPT Cells work together to carry out Cells work together to carry out complex functionscomplex functions

5.3 Cancer / 5.5 Stem Cells

I. Specialized CellsI. Specialized Cells1. Specialized cells perform specific functions1. Specialized cells perform specific functions..

• Cells develop into their mature forms through the process Cells develop into their mature forms through the process of cell differentiationof cell differentiation

2. Cells are different because different 2. Cells are different because different combinations of genes are expressedcombinations of genes are expressed

• A cell’s location in an embryo helps determine how it will A cell’s location in an embryo helps determine how it will differentiatedifferentiate

Outer: skin cellsOuter: skin cells Middle: bone cellsMiddle: bone cells Inner: intestines

5.3 Cancer / 5.5 Stem Cells

II. Stem CellsII. Stem Cells1. Stem cells are unique body cells.1. Stem cells are unique body cells.

2. Stem cells have the ability to:2. Stem cells have the ability to:

– divide and renew themselvesdivide and renew themselves

– remain undifferentiated in formremain undifferentiated in form

– develop into a variety of specialized cell develop into a variety of specialized cell typestypes

5.3 Cancer / 5.5 Stem Cells

First, an egg is fertilized by a sperm cell in a petri dish. The egg divides, forming an inner cell mass. These cells are then removed and grown with nutrients. Scientists try to control how the cells specialize by adding or removing certain molecules.

• Stem cells come from adults and embryosStem cells come from adults and embryos– Adult stem cells can be hard to isolate and grow.Adult stem cells can be hard to isolate and grow.– The use of adult stem cells may prevent transplant The use of adult stem cells may prevent transplant

rejection.rejection.– The use of embryonicThe use of embryonic

stem cells raisesstem cells raisesethical issuesethical issues

– Embryonic stem cellsEmbryonic stem cellscan be grown indefinitelycan be grown indefinitelyin culture.in culture.