Download Chapter 10 Cell Growth and Division How Surface

Chapter 10 Cell Growth and Division
How Surface Area to Volume Ratio Limits Cell Size
DNA “overload” - If cell gets too
big_______ can‛t regulate cellular functions
Exchange of materials –
• All raw materials necessary for metabolism
enter the cell through its ______________
• Nutrients _______ into cell and wastes
diffuse out
• ____________ must allow sufficient exchange
to support the cell
Factors that influence rate of diffusion:
• The rate of diffusion depends on the concentration difference across the two sides of the membrane.
• The rate depends on the permeability of the plasma membrane to the diffusing substance.
• The rate of diffusion through a membrane is also directly proportional to the surface area of the membrane
Cell Size
Surface area = L x W x 6
Volume = L x w x H
Ratio of S/A : V
• Cell‛s surface area to volume ratio determines the _________________
• This ratio limits how large cells can be
• As a cell grows its SA/V ratio ____________
• When SA/V ratio becomes too small the _____________________is too
small to supply enough raw materials to support its volume
• At this point the cell cannot get larger
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M phase ­ AKA Cell Division
only time chromosomes become visible
Four Phases of the Cell Cycle:
G1 - __________
_________and new
__________ are
formed (G=gap)
Interphase
Includes
_________
S phase ___________
_______, and
___________
production
(proteins for:
___________
___________
___________
G2 - cell
_________ and
preparation for
____________
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Mitosis
Division of the cell __________, ___________ and _______________
Produces ______________________cells
Source of ___________for _________ and _______ of damaged cells
Growing cells divide to form two “daughter” cells
1) Prophase - a. _______________________
b. __________________________form
and line up on opposite sides of the nucleus
Interphase
c. _____________________ -disintegrates
Spindle
Centrioles
Centrioles
Nuclear envelope
Centriole
Centromere
Chromatin
Cytokinesis - division
of the __________
________________
________________
Nuclear
Envelope
Forming
4) Telophase-________
___________________
and patches of old
___________________
join to form nuclear
envelope
Spindle
Centriole
2) Metaphase each chromosome
is connected to a
___________at
its ___________
3) Anaphase_________________ • Chromosomes
_________________ are
_____________
into individual
_________________ _____________
_____________
and move apart
Individual Chromosomes
Cytokinesis in plant cells
• rigid walls can‛t be
pinched inward
• __________– cellulose
deposits slowly forms
midway between the
Cell Plate
divided nuclei
• gradually develops into a
________________
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Cyclins
Growth factors, cyclins and p53
gene all regulate the­­­­­­­­­­-___________
____________ - Family of several
different __________ that regulate
the _______
__________________ –Respond to
conditions outside the cell to direct
cells to speed up or slow down the
_____________
• prevents excessive cell growth and
keeps tissues of body from
disrupting one another (such as
embryonic development and wound
healing)
Controlled cell growth -some cells in
a petri dish w/ nutrient broth
Some cells don't respond to
regulatory proteins at this point
and may become cancerous
Cells removed from dish
Cells will grow until
they form a thin
layer covering the
bottom of the dish
Demonstrates that the controls
on cell growth and cell division
can be turned on and off
Cells bordering the
open space will begin
dividing until they
have filled the empty
space
___________________ – Regulate
timing/rate of each phase of the
cell cycle and each step of _______
• Certain processes must happen
before proceeding to next phase
• ___________________ – cells
don‛t __________ or _______
themselves such as _________ and
_______________
Cyclins:
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Uncontrolled Cell Growth
Cancer cells - control over cell cycle
broken down
• Don‛t respond to _________________
that control cell growth
• Carbohydrate chains on plasma
membrane don‛t work
• Don‛t produce _______________ that
control the cell cycle
• Divide uncontrollably and form
__________
_____________ – masses of
cancerous cells that damage
surrounding tissues
• _____________ may break away
and spread to other tissues of the
body - ____________
• _____________________________
_____________________________
• Causes cells to lose the genetic
information needed to respond to the
signals from cyclins that control their
growth
• _____________________________
• ________________ – tells cells how
to respond to internal regulators
(_________)
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