Download 10.3 Notes

10.3 Notes
Regulating Cell Growth
1. Controls on Cell Division
a. Cyclins
i. In the early ___________ biologists discovered a protein that when injected into cells
could cause spindles to form it was called __________. This protein is found in cells that
were undergoing mitosis.
ii. Called cyclin because it seems to regulate the ___________ cycle. Since its discovery a
whole family of cyclins have been discovered that control the timing of the cell cycle in
_______________________ cells.
b. Regulatory Proteins
i. Scientists have since discovered _______________ of other proteins that help to
regulate the cell cycle.
ii. There are ______________ regulators that allow the cell cycle to proceed only when
certain events have occurred inside the cell(ex: chromosome duplication, spindle fibers
formed)
iii. There are also _____________ regulators respond to events outside of the cell and
direct cells to either speed up or slow down the cycle.
1. Ex: Growth factors that stimulate the growth and ___________ of cells. Very
important during embryonic development and _____________ healing.
2. Other proteins will ____________ the cell cycle to keep too much growth from
occuring.
c. Apoptosis
i. Cells die in one of two ways: damage/injury or apoptosis.
ii. Apoptosis is the __________________ cell death where the cell will go through a series
of controlled steps leading to its self-destruction.
1. Cell and chromatin ________________.
2. Parts of the cell ________________ break off.
3. Neighboring cells then quickly clean up the cell’s _______________.
iii. A balance of cell growth/death must occur to keep an ________________ healthy.
2. Cancer: Uncontrolled Cell Growth
a. How do cancer cells differ from other cells?
i. Cancer is a ___________________ in which body cells lose the ability to control growth.
ii. Cancer cells do not respond to the ______________ that regulate the growth of most
cells. As a result cells will _______________ uncontrollably.
iii. Cancer cells form a mass called a _________________. Some are ___________ or noncancerous. However there are others that are _________________ or cancerous. These
will spread to invade and destroy surrounding ______________ tissue. These will
absorb ________________ needed for other cells.
b. What causes cancer?
i. Defects in the _______________ that regulate cell growth and division.
ii. Examples of sources of defects: smoking or chewing tobacco, radiation exposure, other
defective genes, and even _____________ infections.
iii. If a cancer cell can spread into the ______________ ______________ then it can
effectively move into other parts of the body… this is very bad.
c. Treatments for cancer
i. Surgery
1. If a tumor is _________________ , and spotted early enough, it can be treated
this way. Ex: skin cancer.
ii. Radiation
1. If a tumor is growing too fast for surgery then carefully targeted _____________
of radiation can be used to help.
iii. Chemical compounds (Chemotherapy)
1. With these compounds one can possible kill cancer cells, or at least __________
their growth.
2. However it also kills non-cancerous cells which causes serious ___________
effects in patients.
3. Much more work is needed to understand the full ____________ cycle in order
to see what is truly happening in cell division.