Download 10.3 Cell Cycle Control File

Ch.10-3
Regulating the Cell Cycle
POINT > Identify 3 reasons cells divide
POINT > Describe the role of cyclins in cell division
POINT > Identify other factors that affect cell
division
POINT > Define apoptosis
POINT > Discuss causes and treatments of cancer
POINT > Identify 3 reasons
cells divide
1. Growth & Development
POINT > Identify 3 reasons cells divide
1. Growth & Development
2. Repair & Healing
POINT > Identify 3
reasons cells divide
1. Growth & Development
2. Repair & Healing
3. Reproduction (in asexual organisms)
POINT > Describe the role of cyclins in cell division
Cyclins are a family of proteins that regulate
the timing of the cell cycle
Cyclins “tell” the cell when to:
Replicate chromosomes
Divide
Enter another phase of the cell cycle
POINT > Describe the role of cyclins in cell division
Directions (5 min total)
Open textbook to p.288 Answer questions 1-3 with partner
Cyclin production during interphase signals
cell to enter mitosis
Cyclin destruction during mitosis signals cell
to stop dividing and enter interphase
WB CHECK:
When during the cell cycle does cyclin production
occur?
Cyclin production causes the cell to
a) enter interphase
b) prepare for mitosis
c) end mitosis
d) increase active transport
WB CHECK:
When during the cell cycle does cyclin destruction
occur?
Cyclin destruction causes the cell to
a) enter interphase
b) prepare for mitosis
c) undergo cytokinesis
d) increase active transport
POINT > Identify other factors that affect cell division
Many other factors help regulate the cell cycle:
Internal regulators respond to events inside the cell
(attachment of spindle fibers, DNA replication, etc)
Internal regulators allow the cell cycle to proceed only
when certain events (like DNA replication) have been
completed
POINT > Identify other factors that affect cell division
External regulators respond to events outside the cell
(growth factors, cell surface proteins, etc)
These regulators can direct cells to speed up or slow
down the cell cycle
WB CHECK:
What is one event an internal cell cycle regulator might
detect or respond to?
An example of an external cell cycle regulator would be
a) DNA polymerase
b) Cyclins
c) Spindle fiber proteins
d) Growth factors
POINT > Define apoptosis
Apoptosis is “programmed cell death”
through a series of controlled steps
Cells commit “suicide” as part of
normal growth and development
POINT > Define apoptosis
Apoptosis is essential to shaping
structures of tissues and organs in plants
and animals
Cells with mutations or problems with
DNA replication also undergo apoptosis
http://www.dnatube.com/video/1188/Apoptosis-animation
Mouse Embryo Paw
WB CHECK:
Apoptosis is important for
a) ensuring mitosis occurs normally
b) proper development of organs and body structures
c) preventing mutated cells from growing
d) a-c
e) b-c
f) a and c
Melanoma
POINT > Discuss causes
and treatments of cancer
Cancer is a group of disorders
characterized by uncontrolled cell division
Uncontrolled cell division creates tumors (masses of
cancer cells)
Benign tumors do not spread and are usually treatable
Malignant tumors do spread, invading and damaging
other tissues
POINT > Discuss causes and treatments of cancer
Cancer is usually caused by mutations to a cell’s
regulatory genes
(causes of mutations include tobacco, radiation,
natural mutations, and viral infections)
As a result, control over the cell cycle breaks down:
1. Cells don’t respond to external growth factors
2. Cells fail to produce internal regulators
3. Mutated cells fail to undergo apoptosis
POINT > Discuss causes and treatments of cancer
Cancer is usually treated through:
Surgery
Radiation
Classic treatment options
Chemotherapy
Targeted therapy: Newer methods - may use specific
antibodies of immune system to destroy cells
Homework:
Read 286-290
Assess #1-3 page 290
Workbook pages 111-112