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Cell Cycle Just what does a cell do with all its time? Honors Biology Chapter 8.

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Presentation on theme: "Cell Cycle Just what does a cell do with all its time? Honors Biology Chapter 8."— Presentation transcript:

1 Cell Cycle Just what does a cell do with all its time? Honors Biology Chapter 8

2 Cell Division Cell undergoes reproduction Makes “daughter cells” Has to first duplicate its chromosomes WHY? To keep the same number of chromosomes after division

3 gb Asexual Reproduction 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) Sexual Reproduction 2 parents 4 offspring Offspring most likely different from parents Meiosis (multicellular eukaryotes) Makes sex cells

4 Types of Asexual Reproduction Budding an offspring grows out of the body of the parent. Hydra budding hydra (10 secs)budding hydra Budding in Hydra (1:27)Budding in Hydra Spongebob Regeneration Starfish regeneration Regrowth of a limb or organ after damage (not a form of reproduction of whole organism)

5 Asexual Reproduction Parthenogenesis growth and development of embryos occur without fertilization. Aphid Parthenogenesis (Gotta see this one!!!!!!!)Aphid Parthenogenesis Eviction of Drone Bees (5:13)Eviction of Drone Bees Komodo Dragon Parthenogenesis ReproductionKomodo Dragon Parthenogenesis Reproduction

6 Asexual Reproduction Fragmentation Planaria Regeneration Body of parent breaks into distinct pieces, each of which can produce an offspring (is a form of reproduction)

7 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.)Internal budding of coral

8 Asexual Reproduction: Vegetative (no seeds or spores) In Plants Rhizomes Tubers Bulb Corm TUBERS Asexual Vegetative Propagation

9 Asexual Reproduction Paramecium (a protist) Paramecium Binary fissionParamecium Binary fission Amoeba (a protist) Binary Fission in amoeba Amoeba division (1:55)Amoeba division

10 Asexual Reproduction Spores in Plants and Fungi Little black dots of bread mold are spores (becomes an organism) Mold spore dispersal Mold spore dispersal youtube Powder inside a puffball is actually the spores

11 Yeast budding Small growth becomes full yeast cell yeast budding time lapse Cell enlarges and splits in half binary fission of bacteria Bacteria Binary Fission

12 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.

13 BINARY FISSION 1-Chromosome duplicates 2-cell elongates as chromosomes move to poles 3-plasma membrane moves inward and cell wall is made You Tube Binary Fission For prokaryotes and unicellular protists

14 Mitosis: How eukaryotes divide Must divide the genetic material

15 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

16 Chromosomes and centromeres Each chromosome strand has its own centromere

17 Centromere: constricted area of two sister chromatids

18 Sister Chromatids: Identical copies of Genetic Material Happens during S phase

19 During cell division, the DNA replicates. The replicating DNA molecules attach to the plasma membrane. As the cell elongates, the chromosomes are pulled apart.

20 Prokaryotes No membrane around nucleus Simpler Smaller Single chromosome Divide by binary fission Eukaryotes Membrane around nucleus More complex Larger Many chromosomes Divide by mitosis or meiosis

21 How many genes? Genes: working subunits of DNA. In a human cell ~21,000 In a bacterial cell ~3,000

22 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

23 Cell Cycle Game Enter the Cell Cycle GameEnter the Cell Cycle Game (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

24 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 Division and Cell Cycle

25 Cell Cycle Time from first formed from a dividing parent to until its own cell division mcgraw-hill cell cycle

26 Get out your worksheet to fill out what happens in each phase (back of “cell cycle game” Eukaryotic Cell Cycle You Tube (4:20)Eukaryotic Cell Cycle You Tube Interphase = G 1, S, G 2 = 90% of time Mitosis= cell divides = 10% of time

27 What phases make up interphase? (G 1, S, G 2 )

28 G1G1 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

29 GoGo Resting or Permanently no division Maximum Surface area/volume EXAMPLES: Nerve (brain) cells Muscle OR * Liver (will exit G o if damaged) GoGo

30 S Phase DNA synthesis (replicates, makes a copy) At the end the chromosomes consist of sister chromatids FYI Typical cell 6-8 hours

31 G2G2 Growth for mitosis Check for DNA accuracy Final prep before mitosis Centrosome Doubles (MTOC) FYI Typical cell 4-6hours

32 McGraw-Hill: How the cell cycle worksMcGraw-Hill: How the cell cycle works Which of the following represents the correct order of the phases of the cell cycle? A) G 1 -> G 2 -> S -> M B) G 1 -> G 2 -> M -> S C) G 1 -> S -> G 2 -> M D) G 1 -> S -> M -> G 2 E) G 1 -> M -> G 2 -> S

33 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"The Cell Cycle" - multimedia animation by Yannick Mahe and Bernard Ducommun


35 Mitosis (add to cell cycle diagram) Mitosis Cell Drive Through (1:44)  Mitosis Video (6:11) Mitosis Cell Drive Through Mitosis Video Asexual Cell division PPMAT Less than 1 hour


37 Mitosis Phases 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 Animation Mitosis youtube (2:47)Mitosis youtube

38 Plant and Animal Cell Mitosis Plant cell mitosis | Flash simulation, Animation, Illustration, Picture, Diagram – eduMediaPlant cell mitosis | Flash simulation, Animation, Illustration, Picture, Diagram – eduMedia Mitosis | Flash simulation, Animation, Illustration, Picture, Diagram - eduMediaMitosis | Flash simulation, Animation, Illustration, Picture, Diagram - eduMedia

39 Can you tell which phase?

40 Which theory is how the cell cycle works?


42 Control of the Cell Cycle * McGraw-Hill animation__control_of_the_cell_cycle.html McGraw-Hill animation__control_of_the_cell_cycle.html Like a control knob of an automatic washing machine… Get analogy handout

43 Cell Cycle Checkpoints (get out your cell cycle handout) Cell Cycle Checkpoints (6:13)Cell Cycle Checkpoints Cell cycle checkpoints = regulatory pathways that control the order and timing (starting/stopping) of cell cycle transitions (at G1, G2, M)

44 Block out If there is an error at any area, it will be fixed or the cell cycle will stop.

45 (see analogy handout) Checkpoints: will give the cell a signal to proceed to next phase G 1 Cell growth (big enough? Proteins for DNA synthesis? Nutrients?) to replication or G 0 G 2 DNA synthesis (any DNA repair?) Size? M Mitosis (chromosome attachment to spindles)


47 Write this on Cell Cycle Diagram GO Growth Factors (GF) Oncogenes Cyclins and CDKs STOP Tumor suppressor genes CDK inhibitors

48 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 McGraw-Hill Growth Factors Animation Dead cells in red

49 Growth Factor Protein secreted by body cells to stimulate other cells to divide

50 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

51 Cyclins: cdk kinases cdk kinases (2:10) You Tube  Globular molecule animation Cyclin – Cdk – ATP – ball molecules red and teal

52 Cyclins build and degrade as needed to start and stop the phases

53 Cyclin attaches to Cdk P Activated by a phosphate

54 Cyclins build/break-down Cdk’s stay in cell phosphate activates the cdk P

55 cdk + cyclin = MPF “maturation promoting factor” (add to your diagram) Green cyclin attaches to blue kinase – note phosphate is the site of attachment

56 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.

57 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 )

58 *The Cell Cycle: Cyclins and Checkpoints (cyclins and kinases) Major control switches of the cell cycle are cyclin-dependent kinases.

59 Checkpoints: Cyclins and Cdk’s Checkpoints in the Cell Cycle Animation Cyclins, Cdk's, and the Cell Cycle Animation


61 P 53: a “tumor suppressor gene” REGULATES THE CELL CYCLE Rediscovering Biology - Animation ArchiveRediscovering 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)DNA tube action of p53 Chromosome 17


63 p53 White = 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 videop53 video (p53-DNA complex) (1:32)

64 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 McGraw-Hill Tumor Suppressor Gene BIOL 230 Lecture Guide - ADCC Apoptosis by NK Cells (animation)BIOL 230 Lecture Guide - ADCC Apoptosis by NK Cells

65 Apoptosis Severe defects in chromosomes block progression through the cell cycle, and can lead to cell suicide, or apoptosis. Apoptosis You Tube Apoptosis You Tube Apoptosis Video Apoptosis Video

66 What if… If the cell cycle does not work properly?If the cell cycle does not work properly CELL APOPTOSIS=cell death (A-pop-toe-sis) Apoptosis (40 secs) by Cancer QuestApoptosis Apoptosis Video (1.33 mins)Apoptosis Video You Tube Apoptosis Video (4 mins)You Tube Apoptosis Video THEN GO TO THE CANCER POWER POINT TO FIND OUT (“cells gone wild”)

67 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.

68 What types of inhibition are these? Competitive or non- competitive?

69 OVERVIEW VIDEO Bozeman: Cell Cycle, Mitosis, Meiosis (13:39)Bozeman: Cell Cycle, Mitosis, Meiosis

70 Density-dependent inhibition: when crowded cells stop dividing

71 Cancer cells Fail to exhibit density- dependent inhibition

72 Anchorage Dependence Animal cells must be in contact with a solid surface to divide

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