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Word bank -signaling molecule -cell receptor -signal transduction pathway -nuclear signaling -cascade -phosphorylation -ATP -protein -response -nucleus.

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Presentation on theme: "Word bank -signaling molecule -cell receptor -signal transduction pathway -nuclear signaling -cascade -phosphorylation -ATP -protein -response -nucleus."— Presentation transcript:

1 Word bank -signaling molecule -cell receptor -signal transduction pathway -nuclear signaling -cascade -phosphorylation -ATP -protein -response -nucleus -mRNA -second messenger

2 Animation 1) What is flight or fight? 2) What is glycogen?

3 12 days until the final How to use this review: 1) Study notes
2) Do questions without notes 3) For any questions you are stuck on you can look at your notes or phone a friend 4) Use the AP flashcards 5) Make a study group 6) Ask Morris LOTS of questions 7) Know what you know and what you don’t know before the test

4 THE CELL CYCLE: Chapter 12
Without counting the G 0 phase, a cell cycle takes hours for most mammalian cells, and only minutes for E. coli cells

5 http://highered. mcgraw-hill
Take notes on events of each part of the cell cycle Interphase (G1, S, G2) + PMATC

6 Get a whiteboard and beads

7 Mitosis in the Whitefish blastula
Animal mitosis movie





12 Mitosis in Action Spindle=_________ Nucleus=_________
Cell Membrane=______ Chromosome=______

13 Draw the 9 steps of cell cycle
G1 S G2 Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

14 Take out lab report turn in ONLY if you can answer “Yes” to all questions/statements below
1) My discussion is half a page 2) My discussion explain why and not just what happened 3) I used 5 or more voc words Turn to Lab FRQ packet and start question on page 13 -Animal behavior Look at data table a) summarize pattern (2 points) - Identify three physiological or environmental reason that cause this (3 points)

15 The is the 2012 AP Bio Review book. Who wants me to order it for you?

16 I can… Write about the role of PROTEINS in the cell cycle

17 THE MITOTIC CELL CYCLE The mitotic phase alternates with interphase in the cell cycle Cell Cycle flash animation

18 INTERPHASE S G1 (DNA synthesis) Cytokinesis Mitosis G2 MITOTIC
LE 12-5 INTERPHASE S (DNA synthesis) G1 Cytokinesis Mitosis G2 MITOTIC (M) PHASE

19 What are the key parts of each phase?
THE MITOTIC CELL CYCLE The mitotic phase alternates with interphase in the cell cycle What are the key parts of each phase? Mitosis animation

20 The stages of mitotic cell division in an animal cell
The light micrographs show dividing lung cells from a newt, which has 22 chromosomes in its somatic cells. The chromosomes appear blue and the microtubules green. (Know the characteristics of the phases)

21 Review the details of each mitotic phase animal cells
(Know the characteristics of the phases) Mitosis flash animation (Purves)

Cell division functions in reproduction, growth, and repair 

23 Cell division distributes identical sets of chromosomes to daughter cells
Eukaryotic chromosomes. A tangle of chromosomes (stained orange) is visible within the nucleus of this kangaroo rat epithelial cell.

24 Every eukaryotic species has a characteristic number of chromosomes in each cell nucleus
Somatic (nonreproductive) cells have two sets of chromosomes Gametes (reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells Eukaryotic chromosomes consist of chromatin, a complex of DNA and protein that condenses during cell division

25 Our DNA is 6 feet long, how does it fit into a nucleus?
Note: 10,000 nuclei fit on the tip of your pencil



28 Chromosome duplication and distribution during mitosis.
Eukaryotic duplicates each of its multiple chromosomes before it divides. A duplicated chromosome consists of two sister chromatids, which narrow at their centromeres.

29 What do you know about cytoskeleton?

30 The mitotic spindle distributes chromosomes to daughter cells
The assembly of spindle microtubules starts in the centrosome, known as a microtubule-organizing center. During interphase, the single centrosome replicates to form two centrosomes. During prophase they form spindle fibers and migrate to the poles.

31 Role of cytoskeleton



34 The mitotic spindle at metaphase
Each of the two joined chromatids of a chromosome has a kinetochore. Anaphase: proteins holding together the sister chromatids of each chromosome are inactivated and they are now full chromosomes.

35 Experimental evidence supports the hypothesis that kinetochores use motor proteins that "walk" a chromosome along the attached microtubules toward the nearest pole. Meanwhile, the microtubules shorten by depolymerizing at their kinetochore ends In a dividing animal cell, non kinetochore microtubules are responsible for elongating the whole cell during anaphase

36 Cytokinesis divides the cytoplasm
How does it differ in animal and plant cells?

37 In animal cells, cytokinesis occurs by cleavage
The cleavage furrow, which begins as a shallow groove in the cell surface. On the cytoplasmic side, a contractile ring of actin microfilaments and molecules of the protein myosin The contraction of the dividing cell’s ring of microfilaments is like the pulling of drawstrings Cytokinesis animation

38 Cytokinesis in plant cells has no cleavage furrow
During telophase, vesicles derived from the Golgi apparatus move along microtubules to the middle of the cell, where they fuse, producing a cell plate.

39 Mitosis in a plant cell These light micrographs show mitosis in cells of an onion root. How does this differ from animal cell mitosis?

40 Mitosis in eukaryotes may have evolved from binary fission in bacteria
Mitosis video (long)

41 A hypothesis for the evolution of mitosis
Researchers of eukaryotic cell division have observed in modern organisms what they believe are mechanisms of division intermediate between the binary fission of bacteria and mitosis as it occurs in most eukaryotes.

42 This man has cancer of the mouth.

43 Regulation of the Cell cycle
The timing and rate of cell division in different parts of a plant or animal are crucial to normal growth, development, and maintenance. Do all cells have the same cell cycle? Why is regulation of the cell cycle of interest to research? Cancer Growth Flash animation

44 What is Cancer? Cancer means uncontrolled cell growth
The body needs to keep cell growth = cell death Cell cycle checkpoints kill mutated or old cells

45 http://science. education. nih

46 The cell cycle has traffic lights that serve as checkpoints
G1 Phase S Phase Mitosis Cytokinesis G2 Phase Does the body need more cells? Is the cell ready for mitosis?

47 Cancer is caused when the checkpoints are broken and the cell cycle keeps going without stopping
G1 Phase S Phase Mitosis Cytokinesis G2 Phase

48 What are the types of cancer?
*Any part of the body can be cancerous Skin cancer Lung cancer Breast cancer Testicular cancer Colon cancer Liver cancer Brain cancer Lung Cancer Brain Cancer


50 How do you get cancer? How can you get cancer?
Getting hit in the breast? NO Having unprotected sex? Smoking? YES Being in the sun too long?

51 Why is cancer so deadly? *
1) Mutated cells beat the cell cycle checkpoints and keep dividing 2) They form tumors which then stop your body parts from functioning normally 3) Angiogensis – the tumors hijack blood vessels to keep them alive 4) Metastisis – the cells from the tumor travel and infect other parts of your body *

52 Here is the development of colon cancer.

53 Why is Cancer so Hard to Cure?
It is a silent killer, by the time it is found it is already to late 2) Chemo/Radiation therapy can kill cancer cells, but is hard on patients 3) If one cancer cell survives, or travels, cancer will come back

54 Can cancer be prevented?
Cancer is not contagious. There is no guaranteed way to prevent cancer, people can reduce their risk (chance) of developing cancer by: A) not using tobacco products B) choosing foods with less fat and eating more vegetables, fruits, and whole grains C) exercising regularly and maintaining a lean weight D) avoiding the harmful rays of the sun, using sunblock, and wearing clothing that protects the skin

55 Mechanical analogy for the cell cycle control system
In this diagram of the cell cycle, the flat "stepping stones" around the perimeter represent sequential events. Like the control device of an automatic washer.

56 Cell Cycle Checkpoints
A checkpoint is a critical control point where stop and go-ahead signals can regulate the cycle. The G1 checkpoint (the "restriction point”) is most important. If a cell receives a go-ahead signal at the G1 checkpoint, it will usually complete the cycle and divide. If it does not receive a go-ahead signal at that point, it will exit the cycle, switching into a non-dividing state called the G0 phase. G0 (G zero) resting phase Cell Cycle with Checkpoints Animation

57 Many factors are involved in the regulation of the cell cycle

58 RB inhibits cell division
Active Cdk inhibits RB

59 The Cell Cycle Clock: Cyclins and Cyclin-Dependent Kinase
Fluctuations in the abundance and activity of cell cycle control molecules pace the sequential events of the cell cycle. Protein kinases, give the go-ahead signals at the G1 and G2 checkpoints The kinases are present at a constant concentration in the growing cell, but much of the time they are in inactive form. To be active, such a kinase must be attached to a cyclin, a protein that gets its name from its cyclically fluctuating concentration in the cell. These kinases are called cyclin-dependent kinases, or Cdks. The activity of a Cdk rises and falls with changes in the concentration of its cyclin partner. Cdks are relatively constant Cyclins vary in the cycle

60 Cdks are relatively constant
Cyclins vary in the cycle

61 The active enzyme and the activating process can be inhibited by two families of cell cycle inhibitory proteins. Members of the INK4 family bind free CDKs thereby preventing association with cyclins. 2. Members of the CIP family bind and inhibit the active CDK-cyclin complex.

62 Internal and external cues help regulate the cell cycle
Internal Signals: Messages from the Kinetochores: the APC A gatekeeper at the M phase checkpoint delays anaphase. Regulators from kinetochores insures all the chromosomes are properly attached to the spindle at the metaphase plate and the anaphase-promoting complex (APC) is in an inactive state. When all are attached, the APC then becomes active and indirectly triggers both the breakdown of cyclin and the inactivation of proteins holding the sister chromatids together. Degradation of key regulator proteins such as the anaphase inhibitors PDS1 and CUT2, and the mitosis initiator cyclin B, drives the cell cycle forward.


64 Molecular control of the cell cycle at the G2 checkpoint.
The Cdk-cyclin complex called MPF, which acts at the G2 checkpoint to trigger mitosis. The "maturation-promoting factor" triggers the cell’s passage past the G2 checkpoint into M phase Cyclins accumulate during G2 associate with Cdk molecules, the resulting MPF complex initiates mitosis. Later in the M phase, MPF helps switch itself off by initiating a process that leads to the destruction of its cyclin by a protein breakdown mechanism

65 Ubiquitin is part of the pathway for the degradation of proteins

66 Ubiquitin is part of the pathway for the degradation of proteins

67 External Signals: Growth Factors
One example of a growth factor is platelet-derived growth factor (PDGF), which is made by blood cells called platelets. The binding of PDGF molecules to these receptors triggers a signal-transduction pathway that leads to stimulation of cell division. The proliferation of fibroblasts helps heal the wounds.

68 Density-dependent inhibition of cell division.
Most animal cells also exhibit anchorage dependence Cancer cells exhibit neither density-dependent inhibition nor anchorage dependence

69 Cancer cells have escaped from cell cycle controls
Cancer cells do not respond normally to the body’s control mechanisms. They divide excessively and invade other tissues. If unchecked, they can kill the organism. The growth and metastasis of a malignant breast tumor. What is a benign tumor? A malignant tumor? metastasis Breast cancer animation

70 P53 is considered to be a "Guardian of the Genome“
1. Growth arrest: p21, Gadd45, and s. 2. DNA repair: p53R2. 3. Apoptosis: Bax, Apaf-1, PUMA and NoxA.

71 P53 re-enforces the G2 checkpoint
P53 re-enforces the G2 checkpoint. This serves as a “tumor suppressor” protein. In the cell, p53 protein binds DNA, which in turn stimulates another gene to produce a protein called p21 that interacts with a cell division-stimulating protein (cdk2). When p21 is complexed with cdk2 the cell cannot pass through to the next stage of cell division. Mutant p53 can no longer bind DNA in an effective way, and as a consequence the p21 protein is not made available to act as the 'stop signal' for cell division. Thus cells divide uncontrollably, and form tumors.

72 http://highered. mcgraw-hill

73 Explain the following diagram


75 Mitosis vs. Meiosis

76 Meiosis

77 Somatic Cells: body cells Ex. ___________ Made by mitosis Gametes: reproductive cells Ex. ________

78 Diploid: Having 2 copies of each chromosome (2n), one from each parent Somatic cells are diploid Human diploid number is _____ What are the cells in your body that are diploid? Are gametes diploid? Why or why not? How many chromosomes does a sperm and egg have? Haploid: Having only 1 copy of each chromosome (n) Gamete cells are haploid Human haploid number is _____ What are the cells in your body that are haploid?

79 Copy and fill in the chart below.
Organism Diploid # (in somatic cells) Haploid # (in gametes) Cat 19 Rose 12 Goat 30 Rice 24 Dog 39 Chimpanzee 48


81 A pair of chromosomes, 1 from mom and 1 from dad
Homologous pair: A pair of chromosomes, 1 from mom and 1 from dad Carry the same genes (ex. eye color gene) But may contain different information (ex. brown eyes and blue eyes) Eye color gene

82 Mitosis: How our bodies make diploid somatic cells It happens ________________ Meiosis: The special process of making haploid gametes It happens in the ______________ & ______________ Do you do mitosis? Do you do meiosis?

83 Mitosis vs. Meiosis Video

84 Meiosis

85 Homologous Chromosomes are Homies
They are always the same SIZE They always have the same type of INFO, but they are not identical

86 Whiteboard Games All members help to find the answer
There will be a seat number who will write and a seat number who will present

87 Game 1: Whose my Homie? Seat 2—Writes Seat 3--Presents #1 #2 #3
# # #3 # # #6


89 Activity Make 1 set of homologous pairs of chromosomes=2 chromosomes
Put letters on the chromosomes Demonstrate crossing over Tips: Use whiteboard and move beads

90 Game 2: Crossing Over On page 90 all members need to draw crossing over between homologous chromosomes IN COLOR Book pg 276 Drawing 1—2 homologous chromosomes with letters Drawing 2—Crossing over (twisty style) Drawing 3—Final chromosomes

91 On the bottom of page 90 write
Crossing over occurs between homologous chromosomes This only occurs in MEIOSIS Crossing over occurs during prophase 1 and leads to different sperm and egg

92 Dispatch pg 93 Crossing over is when________________
Crossing over occurs during____phase of meiosis

93 Mendel’s 2 Laws

94 Independent Assortment

95 Draw 2 different alignments
On pg 91 write Mendel’s Law of Independent Assortment— homologous chromosomes line up in different combinations during Metaphase I of Meiosis Draw 2 different alignments

96 Game 3: 2 alignments for these 2 homies
j J

97 Draw 4 sperm that are segregated
Mendel’s Law 2 pg 92 Mendel’s Law of Segregation —allele pairs separate during gamete formation and end up in different gametes (sperm and egg) Draw 4 sperm that are segregated

98 Game 4: Segregation or Not?
Seat 4—Writes Seat 1--Presents # #2 # #4

99 Who won? Clean up beads, colored pencils, marker and whiteboard
Get ready for exit quiz

100 Draw a sperm cell that is segregated
Exit Quiz Draw a sperm cell that is segregated Draw 2 alignments for homologous chromosomes in metaphase 1

101 Exit Quiz Explain how the cell cycle is regulated
How does cancer occur? Give 5 differences between mitosis and meiosis

102 Chapter 12~ The Cell Cycle

103 Biology is the only subject in which multiplication is the same thing as division…

104 Why do cells divide? For reproduction For growth For repair & renewal
asexual reproduction one-celled organisms For growth from fertilized egg to multi-celled organism For repair & renewal replace cells that die from normal wear & tear or from injury amoeba Unicellular organisms Cell division = reproduction Reproduces entire organism& increase population Multicellular organisms Cell division provides for growth & development in a multicellular organism that begins as a fertilized egg Also use cell division to repair & renew cells that die from normal wear & tear or accidents 104

105 Importance of Cell Division
1. Growth and Development 2. Asexual Reproduction Tissue Renewal Zygote Embryo Fetus Adult 1 Cell cells millions cells 100 trillion cells

106 DNA organization in Prokaryotes
Nucleoid region Bacterial Chromosome Single (1) circular DNA Small (e.g. E. coli is 4.6X106 bp, ~1/100th human chromosome) Plasmids – extra chromosomal DNA

107 Bacterial Fission

108 The Cell Cycle Interphase (90% of cycle) Mitotic phase
• G1 phase~ growth • S phase~ synthesis of DNA • G2 phase~ preparation for cell division Mitotic phase • Mitosis~ nuclear division • Cytokinesis~ cytoplasm division

109 Parts of Cell Cycle Interphase M phase G1 S phase G2
Mitosis (Division of nucleus) Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis (Division of cytoplasm)

110 Cell Division: Key Roles
Genome: cell’s genetic information Somatic (body cells) cells Gametes (reproductive cells): sperm and egg cells Chromosomes: condensed DNA molecules Diploid (2n): 2 sets of chromosomes Haploid (1n): 1 set of chromosomes Chromatin: DNA-protein complex Chromatids: replicated strands of a chromosome Centromere: narrowing “waist” of sister chromatids Mitosis: nuclear division Cytokinesis: cytoplasm division Meiosis: gamete cell division

111 Chromosome Organization
When cells divide, daughter cells must each receive complete copy of DNA Each cell has about 2 meters of DNA in the nucleus; thin threads called chromatin Before division, condenses to form chromosomes DNA also replicates before cell division to produce paired chromatids 111

112 double-stranded mitotic human chromosomes

113 Normal Karyotype (Fig 18.1)

114 Mitosis Prophase Prometaphase Metaphase Anaphase Telophase

115 Prophase Chromatin condenses visible chromosomes
chromatids Centrioles move to opposite poles of cell animal cell Protein fibers cross cell to form mitotic spindle microtubules Nucleolus disappears Nuclear membrane breaks down

116 Prometaphase spindle fibers attach to centromeres
creating kinetochores microtubules attach at kinetochores connect centromeres to centrioles chromosomes begin moving

117 Metaphase Centrosomes at opposite poles Centromeres are aligned
Kinetochores of sister chromatids attached to microtubules (spindle)

118 118

119 Anaphase Paired centromeres separate; sister chromatids liberated
Chromosomes move to opposite poles Each pole now has a complete set of chromosomes

120 Separation of chromatids
In anaphase, proteins holding together sister chromatids are inactivated separate to become individual chromosomes 1 chromosome 2 chromatids 2 chromosomes single-stranded double-stranded 120

121 Chromosome movement Kinetochores use motor proteins that “walk” chromosome along attached microtubule microtubule shortens by dismantling at kinetochore (chromosome) end Microtubules are NOT reeled in to centrioles like line on a fishing rod. The motor proteins walk along the microtubule like little hanging robots on a clothes line. In dividing animal cells, non-kinetochore microtubules are responsible for elongating the whole cell during anaphase, readying fro cytokinesis 121

122 Telophase Cytokinesis begins cell division Daughter nuclei form
Nuclear envelopes arise Chromatin becomes less coiled Two new nuclei complete mitosis Cytokinesis begins cell division



125 Mitosis in whitefish blastula

126 Mitosis in plant cell 126

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

128 Cytokinesis in Plants Plants cell plate forms
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 128

129 onion root tip 129

130 Any Questions?? 130

131 Cell Cycle regulation Checkpoints
cell cycle controlled by STOP & GO chemical signals at critical points signals indicate if key cellular processes have been completed correctly

132 Checkpoint control system
3 major checkpoints: G1/S can DNA synthesis begin? G2/M has DNA synthesis been completed correctly? commitment to mitosis spindle checkpoint are all chromosomes attached to spindle? can sister chromatids separate correctly? 132

133 G1/S checkpoint G1/S checkpoint is most critical
primary decision point “restriction point” 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 133

134 “Go-ahead” signals Protein signals that promote cell growth & division
internal signals “promoting factors” external signals “growth factors” Primary mechanism of control phosphorylation kinase enzymes either activates or inactivates cell signals We still don’t fully understanding the regulation of the cell cycle. We only have “snapshots” of what happens in specific cases. 134

135 Cell cycle signals Cell cycle controls cyclins Cdks Cdk-cyclin complex
inactivated Cdk Cell cycle controls cyclins regulatory proteins levels cycle in the cell Cdks cyclin-dependent kinases phosphorylates cellular proteins activates or inactivates proteins Cdk-cyclin complex triggers passage through different stages of cell cycle activated Cdk 135

136 External signals Growth factors coordination between cells
protein signals released by body cells that stimulate other cells to divide density-dependent inhibition crowded cells stop dividing each cell binds a bit of growth factor not enough activator left to trigger division in any one cell anchorage dependence to divide cells must be attached to a substrate “touch sensor” receptors 136

137 Growth Factors and Cancer
Growth factors can create cancers proto-oncogenes normally activates cell division growth factor genes become oncogenes (cancer-causing) when mutated if switched “ON” can cause cancer example: RAS (activates cyclins) tumor-suppressor genes normally inhibits cell division if switched “OFF” can cause cancer example: p53 137

138 Cancer & Cell Growth Cancer is essentially a failure of cell division control unrestrained, uncontrolled cell growth What control is lost? lose checkpoint stops gene p53 plays a key role in G1/S restriction point p53 protein halts cell division if it detects damaged DNA options: stimulates repair enzymes to fix DNA forces cell into G0 resting stage keeps cell in G1 arrest causes apoptosis of damaged cell ALL cancers have to shut down p53 activity p53 is the Cell Cycle Enforcer p53 discovered at Stony Brook by Dr. Arnold Levine 138

139 p53 — master regulator gene
NORMAL p53 p53 allows cells with repaired DNA to divide. p53 protein DNA repair enzyme p53 protein Step 1 Step 2 Step 3 DNA damage is caused by heat, radiation, or chemicals. Cell division stops, and p53 triggers enzymes to repair damaged region. p53 triggers the destruction of cells damaged beyond repair. ABNORMAL p53 abnormal p53 protein cancer cell Step 1 Step 2 DNA damage is caused by heat, radiation, or chemicals. The p53 protein fails to stop cell division and repair DNA. Cell divides without repair to damaged DNA. Step 3 Damaged cells continue to divide. If other damage accumulates, the cell can turn cancerous. 139

140 Development of Cancer Cancer develops only after a cell experiences ~6 key mutations (“hits”) unlimited growth turn on growth promoter genes ignore checkpoints turn off tumor suppressor genes (p53) escape apoptosis turn off suicide genes immortality = unlimited divisions turn on chromosome maintenance genes promotes blood vessel growth turn on blood vessel growth genes overcome anchor & density dependence turn off touch-sensor gene It’s like an out-of-control car with many systems failing! 140

141 What causes these “hits”?
Mutations in cells can be triggered by UV radiation chemical exposure radiation exposure heat cigarette smoke pollution age genetics 141

142 Tumors Mass of abnormal cells Benign tumor Malignant tumor
abnormal cells remain at original site as a lump p53 has halted cell divisions most do not cause serious problems & can be removed by surgery Malignant tumor cells leave original site lose attachment to nearby cells carried by blood & lymph system to other tissues start more tumors = metastasis impair functions of organs throughout body 142

143 Cancer: breast cancer cell & mammogram

144 Traditional treatments for cancers
Treatments target rapidly dividing cells high-energy radiation kills rapidly dividing cells chemotherapy stop DNA replication stop mitosis & cytokinesis stop blood vessel growth 144

145 New “miracle drugs” Drugs targeting proteins (enzymes) found only in cancer cells Gleevec treatment for adult leukemia (CML) & stomach cancer (GIST) 1st successful drug targeting only cancer cells Proof of Principle: you can treat cancer by targeting cancer-specific proteins. GIST = gastrointestinal stromal tumors, which affect as many as 5,000 people in the United States CML = chronic myelogenous leukemia, adult leukemia, which affect as many as 8,000 people in the United States Fastest FDA approval — 2.5 months without Gleevec with Gleevec Novartes 145

146 Any Questions?? 146

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