The Cell Cycle: Cell Growth, Cell Division - PowerPoint PPT Presentation

Loading...

PPT – The Cell Cycle: Cell Growth, Cell Division PowerPoint presentation | free to download - id: 702d54-ZmIwM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

The Cell Cycle: Cell Growth, Cell Division

Description:

The Cell Cycle: Cell Growth, Cell Division Cell cycle signals Cell cycle controls Cyclin regulatory proteins levels cycle in the cell CDK cyclin-dependent kinases ... – PowerPoint PPT presentation

Number of Views:128
Avg rating:3.0/5.0
Slides: 34
Provided by: 00166
Learn more at: http://campuses.fortbendisd.com
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: The Cell Cycle: Cell Growth, Cell Division


1
The Cell Cycle Cell Growth, Cell Division
2
Where it all began
  • You started as a cell smaller than a period at
    the end of a sentence

3
And now look at you
How did you get from there to here?
4
Why do cells divide?
  • Reproduction
  • asexual reproduction
  • one-celled organisms
  • Growth and Development
  • from fertilized egg to multi-celled organism
  • Repair and Replacement
  • replace cells that die from normal wear tear or
    from injury

amoeba
5
Cell Cycle
6
Cell cycle
  • Cell has a life cycle

cell is formed from a mitotic division
cell grows matures to divide again
cell grows matures to never divide again
G1, S, G2, M
G1?G0
liver cells
epithelial cells,blood cells, stem cells
brain / nerve cells muscle cells
7
Interphase
  • 90 of cell life cycle
  • cell doing its everyday job
  • produce RNA, synthesize proteins/enzymes
  • prepares for duplication if triggered

Im working here!
Time to divide multiply!
8
Interphase
  • Divided into 3 phases
  • G1 1st Gap
  • cell doing its everyday job
  • cell grows
  • A few hours to indefinitely
  • S DNA Synthesis
  • copies chromosomes
  • 3-6 hours
  • G2 2nd Gap
  • prepares for division
  • cell grows (more)
  • produces organelles,proteins, membranes
  • 2-5 hours

9
Interphase
green key features
  • Longest phase of the cell cycle
  • Consists of G1, S, G2
  • Cell prepares for mitosis
  • replicates chromosome
  • DNA proteins
  • produces proteins organelles

10
Organizing DNA
ACTGGTCAGGCAATGTC
DNA
  • DNA is organized in Nucleosomes
  • double helix DNA molecule
  • wrapped around Histones
  • like thread on spools
  • DNA-protein complex Chromatin
  • organized into long thin fiber
  • condensed further during mitosis

histones
chromatin
double stranded chromosome
duplicated mitotic chromosome
11
Copying DNA packaging it
  • After DNA duplication, chromatin condenses
  • coiling folding to make a smaller package

mitotic chromosome
DNA
chromatin
12
double-strandedmitotic humanchromosomes
13
Mitotic Chromosome
  • Duplicated chromosome
  • 2 chromatids
  • narrow at centromere
  • contain identical copies of original DNA

single-stranded
homologous same information
double-stranded
14
Mitosis
  • Dividing cells DNA between 2 daughter nuclei
  • dance of the chromosomes
  • 4 phases
  • Prophase
  • Metaphase
  • Anaphase
  • Telophase

15
Mitosis
16
Overview of mitosis
I.P.M.A.T.
interphase
prophase
(pro-metaphase)
cytokinesis
metaphase
anaphase
telophase
17
Prophase
green key features
  • Chromatin condenses
  • Becomes chromosomes
  • chromatids
  • Centrioles move to opposite poles of cell
  • animal cell
  • Protein fibers cross cell to form mitotic spindle
  • microtubules
  • actin, myosin
  • coordinates movement of chromosomes
  • Nucleolus disappears

18
Transition to Metaphase
green key features
  • Prometaphase
  • Special proteins attach to the centromeres
  • creating kinetochores
  • microtubules attach at kinetochores
  • connect centromeres to centrioles
  • Nuclear envelope fragments

19
Anaphase
green key features
  • Sister chromatids separate
  • move to opposite poles
  • pulled at centromeres
  • pulled by motor proteins walkingalong
    microtubules
  • actin, myosin
  • increased production of ATP by mitochondria
  • Poles move farther apart
  • polar microtubules lengthen

20
Telophase
green key features
  • Chromosomes arrive at opposite poles
  • Nuclear envelop starts to reappear
  • nucleoli form
  • Chromosomes uncoil
  • no longer visible under light microscope
  • Spindle fibers disperse
  • Cytokinesis
  • cell division

21
Cytokinesis
  • Animals
  • constriction belt of actin microfilaments around
    equator of cell
  • cleavage furrow forms
  • splits cell in two
  • like tightening a draw string

22
Mitosis in whitefish blastula
23
Cytokinesis in Plants
  • Plants
  • Cell Plate
  • vesicles line up at equator
  • derived from Golgi
  • vesicles fuse to form 2 cell membranes
  • new cell wall laid down between membranes
  • new cell wall fuses with existing cell wall

24
Cytokinesis in plant cell
25
onion root tip
26
G1/S checkpoint
  • G1/S checkpoint is most critical
  • primary decision point
  • Go Ahead signal
  • if cell receives GO signal, it divides
  • internal signals cell growth (size), cell
    nutrition
  • external signals growth factors
  • if cell does not receive signal, it exits cycle
    switches to G0 phase
  • non-dividing, working state

27
What about Stem cells?
  • What are stem cells?
  • How can they be used?
  • What are concerns about using stem cells?
  • What are the types of stem cells?

28
Multicellular organisms depend on interactions
among different cell types.
  • Tissues are groups of cells that perform a
    similar function.
  • Organs are groups of tissues that perform a
    specific or related function.
  • Organ systems are groups of organs that carry out
    similar functions.

29
Specialized cells perform specific functions.
  • Cells develop into their mature forms through the
    process of cell differentiation.
  • Cells differ because different combinations of
    genes are expressed.
  • A cells location in an embryo helps determine
    how it will differentiate.

30
Stem cells can develop into different cell types.
  • Stem cells have the ability to
  • divide and renew themselves
  • remain undifferentiated in form
  • develop into a variety of specialized cell types

31
  • Stem cells are classified into three types.
  • totipotent, or growing into any other cell type
  • pluripotent, or growing into any cell type but a
    totipotent cell
  • multipotent, or growing into cells of a closely
    related cell family

32
  • Stem cells come from adults and embryos.
  • Adult stem cells can be hard to isolate and grow.
  • The use of adult stem cells may prevent
    transplant rejection.
  • The use of embryonicstem cells raisesethical
    issues.
  • Embryonic stem cellsare pluripotent andcan be
    grown indefinitelyin culture.

33
  • The use of stem cells offers many current and
    potential benefits.
  • Stem cells are used to treat leukemia and
    lymphoma.
  • Stem cells may cure disease or replace damaged
    organs.
  • Stem cells Blindness
  • Stem cells may revolutionize the drug development
    process.

34
Cell cycle signals
inactivated Cdk
  • Cell cycle controls
  • Cyclin
  • regulatory proteins
  • levels cycle in the cell
  • CDK
  • cyclin-dependent kinases
  • phosphorylates cellular proteins
  • activates or inactivates proteins
  • MPF
  • triggers passage through different stages of cell
    cycle

activated Cdk
About PowerShow.com