Transcript Cell Cycle - hudson.edu

Honors Biology Chapter 8
Cell
Cycle
Just what does a cell do with all its
time?
Cell Division
•
•
•
•
•
Cell undergoes reproduction
Makes “daughter cells”
Has to first duplicate its chromosomes
WHY?
To keep the same number of
chromosomes after division
Asexual Reproduction
Sexual Reproduction
gb
Types of Asexual Reproduction
• One parent
• 2 offspring
• Offspring identical to
parents (if no mutations)
• Mitosis (eukaryotes)
• Binary fission
(prokaryotes +
unicellular organisms)
• Makes somatic cells (non
sex cells)
• 2 parents
• 4 offspring
• Offspring most likely
different from parents
• Meiosis (multicellular
eukaryotes)
• Makes sex cells
Types of Asexual Reproduction
Budding
• an offspring grows out of
the body of the parent.
• Hydra
• budding hydra (10 secs)
• Budding in Hydra (1:27)
• Spongebob
Regeneration
Starfish regeneration
Regrowth of a limb or organ
after damage (not a form of
reproduction of whole
organism)
Asexual Reproduction
Parthenogenesis
• growth and development
of embryos occur without
fertilization.
• Aphid Parthenogenesis (Gotta
see this one!!!!!!!)
• Eviction of Drone Bees (5:13)
• Komodo Dragon
Parthenogenesis Reproduction
Asexual Reproduction
Fragmentation
Planaria Regeneration
Body of parent breaks into
distinct pieces, each of which
can produce an offspring (is a
form of reproduction)
Asexual Reproduction
Gemmules (internal buds)
• internally-produced,
asexual bud (new sponge
– even if adult does not
survive)- usually under
stress
-Sexual reproduction of the sponge
-Sponges: Facts
• Internal budding of coral
(mushroom coral 55 secs.)
Asexual Reproduction:
Vegetative (no seeds or spores)
In Plants
• Rhizomes
• Tubers
• Bulb
• Corm
TUBERS
Asexual Vegetative
Propagation
Asexual Reproduction
Paramecium (a protist)
• Paramecium Binary
fission
Amoeba (a protist)
• Binary Fission in amoeba
• Amoeba division (1:55)
Asexual Reproduction
Mold spore dispersal
Spores in Plants and
Fungi
Mold spore dispersal youtube
• Little black dots of bread
• Powder inside a puffball
mold are spores
is actually the spores
(becomes an organism)
Yeast budding
Small growth becomes
full yeast cell
yeast budding time lapse
Bacteria Binary Fission
Cell enlarges and splits in
half
binary fission of bacteria
Recap: Asexual Reproduction
Binary Fission
• Division of a cell
(prokaryotes and
unicellular organisms)
into two identical cells
Mitosis
• a eukaryotic cell
separates the
chromosomes in its
nucleus into two identical
nuclei.
•
BINARY
FISSION
For prokaryotes
and unicellular
• 1-Chromosome protists
duplicates
• 2-cell elongates
as chromosomes
move to poles
• 3-plasma membrane
moves inward and
cell wall is made
You Tube Binary Fission
Mitosis: How eukaryotes divide
Must divide the genetic material
ALL DNA + Protein
CHROMATIN
Loose
During non-division
Not visible with light
microscope
CHROMOSOME
Single stranded
Somewhat coiled
Visible with microscope
• CHROMATID
• Paired homologous
chromosomes during
cell division
• Densely coiled
• Visible with microscope
Chromosomes and centromeres
• Each chromosome strand has its own
centromere
Centromere: constricted area of
two sister chromatids
Sister Chromatids:
Identical copies of Genetic Material
Happens during S phase
• During cell division, the DNA replicates.
The replicating DNA molecules attach to
the plasma membrane. As the cell
elongates, the chromosomes are pulled
apart.
• Prokaryotes
• Eukaryotes
• No membrane around•
nucleus
• Simpler
•
• Smaller
•
• Single chromosome •
• Divide by binary
•
fission
Membrane around
nucleus
More complex
Larger
Many chromosomes
Divide by mitosis or
meiosis
How many genes?
Genes: working subunits of DNA.
• In a human cell
• ~21,000
• In a bacterial cell
• ~3,000
Sexual
Reproduction
-Used to make egg
and sperm (that will
join later)
-Increases
diversity
Asexual
Reproduction
• Used to
replace dead
cells
• Growth of new
parts (size)
• New organism
identical to
parent
Cell Cycle Game
• Enter the Cell
Cycle Game
• Nobelprize.org
• (use Firefox
)
• “Educational
Games”
• Scroll down to
• Cell cycle game
• FUN!!!!!!!!!!!!!!!!!
Top 10 most visited educational games
1. The Blood Typing Game
2. The Laser Challenge Game
3. The DNA - the Double Helix Game
4. The Pavlov's Dog Game
5. The Diabetic Dog Game
6. The Lord of the Flies Game
7. The Electrocardiogram Game
8. The Immune System Game
9. The Control of the Cell Cycle Game
10. The Split Brain Experiments Game
Cell Cycle
• = Time from when a cell is first formed
from its dividing parent cell to its own
division into daughter cells.
• Cell Division and Cell Cycle Sit back and
relax and enjoy the big picture of cell
division (5.5 mins)
Cell Cycle
• Time from first formed from a dividing
parent to until its own cell division
• mcgraw-hill cell cycle
Get out your worksheet to fill out what
happens in each phase (back of
Nobelprize.org “cell cycle game”
• Eukaryotic Cell Cycle You Tube (4:20)
• Interphase = G1, S, G2 = 90% of time
• Mitosis= cell divides = 10% of time
What phases make up
interphase? (G1, S, G2)
G1
• Growth of the Cell
• Makes more organelles
(mitochondria and ribosomes)
• Plasma membrane got larger
(needs more lipids, carbos,
proteins)
• High energy activity (cell resp.)
• FYI Typical cell 8-10 hours
Go
• Resting or Permanently
no division
• Maximum Surface area/volume
EXAMPLES: Nerve (brain) cells
•
Muscle
Go
• OR
* Liver (will exit Go if damaged)
S Phase
• DNA synthesis
(replicates, makes a copy)
• At the end the chromosomes
consist of sister chromatids
• FYI Typical cell 6-8 hours
G2
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•
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Growth for mitosis
Check for DNA accuracy
Final prep before mitosis
Centrosome Doubles
(MTOC)
• FYI Typical cell 4-6hours
• McGraw-Hill: How the cell cycle
works
• Which of the following represents
the correct order of the phases of
the cell cycle?
• A) G1 -> G2 -> S -> M
• B) G1 -> G2 -> M -> S
• C) G1 -> S -> G2 -> M
• D) G1 -> S -> M -> G2
• E) G1 -> M -> G2 -> S
Can you tell what goes on in each?
• Cell Cycle Movie
• Try this one…"The Cell Cycle" multimedia animation by Yannick Mahe
and Bernard Ducommun
Interphase = G1, S, G2
Cell is
performing
its various
metabolic
activities
90% of cell
cycle time
Mitosis (add to cell cycle diagram)
Mitosis Cell Drive Through (1:44)
Mitosis Video (6:11)
• Asexual Cell division
• PPMAT
• Less than 1 hour
Mitosis: M phase
Mitosis Phases
(1:22 fly-through)
• Mitosis Animation scroll to middle of page
(nice and slow so you can concentrate on
all that is happening)
• Mitosis youtube (2:47)
Plant and Animal Cell Mitosis
• Plant cell mitosis | Flash simulation,
Animation, Illustration, Picture, Diagram –
eduMedia
• Mitosis | Flash simulation, Animation,
Illustration, Picture, Diagram - eduMedia
Can you tell which phase?
Which theory is how the cell
cycle works?
Which theory is how the cell
cycle works?
Control of the Cell Cycle
*McGraw-Hill
animation__control_of_the_cell_cycle.html
• Like a control knob of an automatic
washing machine…
•
Get
analogy
handout
Cell Cycle Checkpoints
(get out your cell cycle handout)
• Cell Cycle Checkpoints (6:13)
• Cell cycle checkpoints =
regulatory pathways that control
the order and timing
(starting/stopping) of cell cycle
transitions
• (at G1, G2, M)
Block out
If there is an error at any area, it will
be fixed or the cell cycle will stop.
(see analogy handout)
Checkpoints: will give the cell a
signal to proceed to next phase
• G1 Cell growth (big enough? Proteins for
DNA synthesis? Nutrients?) to replication
or G0
• G2 DNA synthesis (any DNA repair?)
Size?
• M Mitosis (chromosome attachment to
spindles)
Write this on Cell Cycle Diagram
• GO
• STOP
• Growth Factors
(GF)
• Oncogenes
• Cyclins and CDKs
• Tumor
suppressor
genes
• CDK inhibitors
VOCAB WORDS:
Growth Factor
• When a cell dies, surrounding cells
will send out a chemical (GF) that
triggers the start of the cell cycle.
•
McGraw-Hill Growth Factors Animation 
Dead cells in red
Growth Factor
• Protein secreted by body cells to
stimulate other cells to divide
Control of the Cell Cycle
• VOCAB WORD: Cyclins - proteins
that start and stop each step of the cell
cycle (concentrations change)
• They build up
• They break down
Cyclins:
cdk kinases
(2:10) You Tube
Globular molecule animation
Cyclin –
Cdk –
ATP – ball molecules red and
teal
Cyclins build and degrade as
needed to start and stop the
phases
Cyclin attaches to Cdk
Activated by a
phosphate
P
Cyclins build/break-down
Cdk’s stay in cell
P
•
• phosphate
activates the cdk
cdk + cyclin = MPF
“maturation promoting factor”
(add to your diagram)
Green cyclin attaches
to blue kinase – note
phosphate is the site
of attachment
Cyclins bind to a Cdk
• Animation of cyclins, cdk's
(shows cdk + cyclin = MPF)
Nobel Prize
winner 2001:
discovered the
key regulators of
the cell cycle,
cyclin dependent
kinase (CDK)
and cyclin.
CDK and CYCLINS
• Each cyclin-dependent kinase (cdk) forms a
complex with a particular cyclin, a protein that
binds and activates the cdk.
• The kinase part of the complex is an enzyme
that adds a phosphate (makes the molecule
unstable to cause it to be more reactive)
• *The Cell Cycle: Cyclins and Checkpoints
(cyclins and kinases)
• Major control switches of the cell cycle are
cyclin-dependent kinases.
Checkpoints: Cyclins and Cdk’s
• Checkpoints in the Cell Cycle Animation
• Cyclins, Cdk's, and the Cell Cycle Animation
P53:
a “tumor suppressor
gene”
• REGULATES THE
CELL CYCLE
• Rediscovering Biology Animation Archive
• p53 can stop and
check a damaged
DNA strand + repair it
• “the guardian of the
genome”
• DNA tube action of p53 (5:18)
Chromosome 17
White = p53
p53
common mutation
changes arginine
248, colored red
here.
DNA is blue and
green
Other key sites of
mutation are shown in
pink, including
arginine residues 175,
249, 273 and 282, and
glycine 245.
p53 video (p53-DNA complex) (1:32)
How does p53 protect the cells?
• 1. start DNA repair
• 2. stop the cell cycle
• 3. initiate apoptosis = cell death, if
DNA cannot be repaired
• McGraw-Hill Tumor Suppressor Gene 
•
BIOL 230 Lecture Guide - ADCC Apoptosis by NK Cells (animation)
Apoptosis
• Severe defects in chromosomes block
progression through the cell cycle, and
can lead to cell suicide, or apoptosis.
• Apoptosis You Tube 
• Apoptosis Video 
What if…
• If the cell cycle does not work
properly?
• CELL APOPTOSIS=cell death
• (A-pop-toe-sis)
• Apoptosis (40 secs) by Cancer Quest
• Apoptosis Video (1.33 mins)
• You Tube Apoptosis Video (4 mins)
• THEN GO TO THE CANCER POWER
POINT TO FIND OUT (“cells gone wild”)
p27
• p27 is a protein that binds to cyclin and
cdk blocking entry into S phase.
• Recent research (Nature Medicine 3, 152
(1997)) suggests that breast cancer prognosis
is determined by p27 levels.
What types of inhibition are
these? Competitive or noncompetitive?
OVERVIEW VIDEO
• Bozeman: Cell Cycle, Mitosis, Meiosis
(13:39)
Density-dependent inhibition:
when crowded cells stop dividing
Cancer cells
• Fail to exhibit densitydependent inhibition
Anchorage Dependence
• Animal cells must be in contact with
a solid surface to divide