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10-1 Cell Growth10-1 Cell Growth
Complete Guided Reading Workbook Complete Guided Reading Workbook 10-1 and 10-210-1 and 10-2
Interest GrabberInterest Grabber
Getting ThroughGetting Through
Materials move through cells by diffusion. Oxygen and food move into Materials move through cells by diffusion. Oxygen and food move into cells, while waste products move out of cells. How does the size of a cells, while waste products move out of cells. How does the size of a cell affect how efficiently materials get to all parts of a cell?cell affect how efficiently materials get to all parts of a cell?
Work with a partner to complete this activity.Work with a partner to complete this activity.
1. On a sheet of paper, make a drawing of a cell that has the following dimensions: 5 cm x 5 cm x 5 cm. Your partner should draw another cell about one half the size of your cell on a separate sheet of paper.
2. Compare your drawings. How much longer do you think it would taketo get from the cell membrane to the center of the big cell than from the cell membrane to the center of the smaller cell?
3. What is the advantage of cells being small?
Go to Section:
By the end of today you will be By the end of today you will be able to:able to:
Explain the problems that growth Explain the problems that growth causes for cells.causes for cells.
Describe how cell division solves the Describe how cell division solves the problems of cell growth.problems of cell growth.
Name and describe the main events Name and describe the main events of the cell cycle.of the cell cycle.
11stst problem: problem: Cell size and material Cell size and material
exchangeexchange The larger a cell The larger a cell
grows the more grows the more trouble it has…trouble it has…
moving enough moving enough nutrients innutrients in
Moving all the Moving all the waste materials waste materials outout
22ndnd problem: DNA overload problem: DNA overload
Checkpoint!!!!Checkpoint!!!! What are two problems that cell growth What are two problems that cell growth
causes for cells?causes for cells? The larger a cell becomes, the more demands The larger a cell becomes, the more demands
the cell places on its _____ and the more the cell places on its _____ and the more trouble the cell has movingtrouble the cell has moving enough enough _________and _________ across the cell _________and _________ across the cell membrane.membrane.
What is viable solution for cells solve these What is viable solution for cells solve these problems?problems? Cell Division – A larger cell splits into two Cell Division – A larger cell splits into two
smaller daughter cells.smaller daughter cells.
The Cell Cycle The Cell Cycle and Mitosisand Mitosis
Chapter 10-2Chapter 10-2Homework 10-2-3 in guided Homework 10-2-3 in guided
readingreading
Cell Cycle
The cell cycle represents recurring events that take place in the period of time from the beginning of one cell division to the beginning of the next. In addition to cell division, the cell cycle includes periods when the cell is growing and actively producing materials it needs for the next
division.
1. Why is the cell cycle called a cycle?2. Why do you think that it is important for a cell to grow in size during
its cell cycle?3. What might happen to a cell if all events leading up to cell division
took place as they should, but the cell did not divide?
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The The Cell CycleCell Cycle - series of events - series of events that cells go through as they grow that cells go through as they grow
and divideand divide The cell cycle is The cell cycle is
divided into two divided into two halfshalfs InterphaseInterphase - -
period of the cell period of the cell cycle between cycle between cell divisionscell divisions
M phaseM phase – – period of time period of time when mitosis and when mitosis and cell divisioncell division occursoccurs
Parts of Parts of InterphaseInterphase
GG11 Phase Phase GrowingGrowing Synthesize new proteins and Synthesize new proteins and
organellesorganelles Doing their jobsDoing their jobs Longest phase of cell cycleLongest phase of cell cycle
S PhaseS Phase Chromosomes (DNA) are Chromosomes (DNA) are
replicatedreplicated Key proteins associated with Key proteins associated with
replication are made replication are made (centromeres)(centromeres)
GG22 Phase Phase Shortest of the 3 phases of Shortest of the 3 phases of
interphaseinterphase Organelles and molecules for cell Organelles and molecules for cell
division are produced (centrioles)division are produced (centrioles) Check-up phase before mitosisCheck-up phase before mitosis
includes
is divided into is divided into
Concept MapConcept Map
Cell Cycle
M phase (Mitosis)
Interphase
G1 phase S phase ProphaseG2 phase Metaphase TelophaseAnaphase
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Chromatin and Chromatin and ChromosomesChromosomes
Chromatin - A complex of DNA and Chromatin - A complex of DNA and proteins in the cell nucleus that proteins in the cell nucleus that condenses to form chromosomes condenses to form chromosomes during cell division.during cell division.
Chromosomes – Condensed Chromosomes – Condensed ChromatinChromatin
They are the same stuff, just in They are the same stuff, just in different formsdifferent forms
Chromatin condenses in Chromatin condenses in chomosomes before mitosis beginschomosomes before mitosis begins
ChromatinChromatin ChromosomesChromosomes
ChromosomesChromosomes
Different organisms have different Different organisms have different #’s of chromosomes#’s of chromosomes
Humans cells – 46Humans cells – 46 Fruit Fly cells – 8Fruit Fly cells – 8 Carrot cells – 18Carrot cells – 18 King Crab cells - 208 King Crab cells - 208
Chromosomes Chromosomes ReplicationReplication During the cell cycle (before During the cell cycle (before
cell division can take place) cell division can take place) chromosomes are replicated to chromosomes are replicated to form an identical copy of form an identical copy of itself.itself.
Two identical copies of a Two identical copies of a chromosome are called chromosome are called “sister” chromatids – (one of “sister” chromatids – (one of two identical “sister” parts of a two identical “sister” parts of a duplicated chromosome)duplicated chromosome)
Centromere - Centromere - area where area where the chromatids of a the chromatids of a chromosome are chromosome are attachedattached
M Phase, Cell Division and M Phase, Cell Division and MitosisMitosis
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Figure 10–5 Mitosis and Figure 10–5 Mitosis and CytokinesisCytokinesis
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Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Figure 10–5 Mitosis and Figure 10–5 Mitosis and CytokinesisCytokinesis
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Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Figure 10–5 Mitosis and Figure 10–5 Mitosis and CytokinesisCytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Figure 10–5 Mitosis and Figure 10–5 Mitosis and CytokinesisCytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Figure 10–5 Mitosis and Figure 10–5 Mitosis and CytokinesisCytokinesis
Go to Section:
Centrioles
Chromatin
Interphase
Nuclear envelope
Cytokinesis
Nuclear envelope reforming
Telophase
Anaphase
Individual chromosomes
Metaphase
Centriole
Spindle
CentrioleChromosomes
(paired chromatids)
Prophase
Centromere
Spindle forming
Figure 10–5 Mitosis and Figure 10–5 Mitosis and CytokinesisCytokinesis
Go to Section:
MitosisMitosis
ProphaseProphase
MetaphaseMetaphase
AnaphaseAnaphase
TelophaseTelophase
CytokinesisCytokinesis
-Cytoplasmic division and other changes exclusive of nuclear division that are a part of mitosis or meiosis.
In plant cells, a cell plate forms. The cell plate is synthesized by the fusion of multiple membrane-
bounded vesicles. Their fusion supplies new plasma membrane for each of the two daughter cells. Synthesis
of a new cell wall between the daughter cells then occurs at the cell plate.
CheckpointCheckpoint
1. The break down of a cell’s entire life is 1. The break down of a cell’s entire life is the _______ ________.the _______ ________.
2. The phase of the cell cycle when the 2. The phase of the cell cycle when the cell is growing, replicating DNA and cell is growing, replicating DNA and getting ready for mitosis is _____________.getting ready for mitosis is _____________.
3-6. What are the four phases of Mitosis?3-6. What are the four phases of Mitosis? 7. The process of a cell actually splitting 7. The process of a cell actually splitting
in two is called _______________.in two is called _______________.
10-3 cell cycle regulation10-3 cell cycle regulation Homework 10-3 guided reading workbookHomework 10-3 guided reading workbook Quiz, Chapter 10, on Thursday!!!Quiz, Chapter 10, on Thursday!!!
Controls on Cell DivisionControls on Cell Division
How do cells know when to How do cells know when to divide and when not to?divide and when not to?
Internal regulators – are proteins Internal regulators – are proteins that respond to events inside the that respond to events inside the cell.cell. CyclinsCyclins
External regulators - Proteins that External regulators - Proteins that respond to events outside the cell respond to events outside the cell are called external regulators.are called external regulators.
CyclinsCyclins• Family of Proteins that
periodically rise and fall in concentration in step with the eukaryotic cell cycle.
• Cyclins activate crucial protein kinases (called cyclin-dependent protein kinases, or CDK) and thereby help control the progression from one stage of the cell cycle to the next.
Cascade of events!!
External RegulatorsExternal Regulators External regulators - Proteins that respond to External regulators - Proteins that respond to
events outside the cell are called external events outside the cell are called external regulators. regulators.
External regulators direct cells to speed up or External regulators direct cells to speed up or slow down the cell cycle. slow down the cell cycle.
Growth factors are among the most important Growth factors are among the most important external regulators, which tell cells to speed external regulators, which tell cells to speed up division. When is this important?up division. When is this important?
Molecules found on the surfaces of Molecules found on the surfaces of neighboring cells often have an opposite neighboring cells often have an opposite effect, causing cells to slow down or stop their effect, causing cells to slow down or stop their cell cycles. cell cycles.
Uncontrolled Cell GrowthUncontrolled Cell Growth Cancer cellCancer cell
Various forms of cancer have many causesVarious forms of cancer have many causes SmokingSmoking RadiationRadiation Viral infectionsViral infections
The common thread in all cancers is The common thread in all cancers is that control over the cell cycle has that control over the cell cycle has broken down.broken down.
Over 50% of cancer cells have a defect Over 50% of cancer cells have a defect in the p53 gene.in the p53 gene.