Cells

1
Cells

• Cell Structure and Function
• Photosynthesis
• Cellular Respiration
• Cell Growth and Division

2
Cell Structure and Function(Chapter 7)
3
Life is Cellular

• How did the Cell Theory develop?
• Cell Theory Guided Reading activity
• Know the contributions of the following
  scientists
• Robert Hooke (1665)
• Anton van Leeuwenhoek (1674)
• Matthias Schleiden (1838)
• Theodor Schwann (1839)
• Rudolph Virchow (1855)
• Janet Plowe (1931)
• Lynn Margulis (1970)

4
The Compound Microscope

• Review the microscope lab activity as notes for
  this section!
• Know the parts of the microscope and be able to
  accurately label a microscope diagram!
• Know how to make a wet mount slide!

5
Prokaryotes vs. Eukaryotes

• Prokaryotes

• Eukaryotes

Use my website to determine the major differences
between eukaryotes and prokaryotes.
6
Cellular Diversity

• Protists
• Webquest on What are Protists?
• Protista lab activity
• Animal and Plant Cells
• Observing Animal and Plant Cells lab activity

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Protist Lab Video Clips

• Paramecium
• http//www.youtube.com/watch?vl9ymaSzcsdYNR1fe
  aturefvwp
• Euglena
• http//www.youtube.com/watch?v7DALQ-XLJ4Qfeature
  related
• Amoeba
• http//www.youtube.com/watch?vI3Jo7moaLdIfeature
  related

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Cell Structures

• Use the webquest on animal and plant cell
  organelles and their functions as notes for this
  section.
• Go to my website, click on links, then click on
  cells alive!
• Or go to http//www.cellsalive.com for more
  information!
• AND review the Cell part puppet show script!

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Structure and Function
20 minute research activity

• Choose a cell type and research how its
  structure helps it function.

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Cells performing the same function often are
similar in shape

• Choose from one of these cell types
• Neuron
• Red Blood Cell
• Cheek Epithelial Cell

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Neuron
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Cheek Epithelial Cell
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Red Blood Cell
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Neuron Notes
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Cheek Epithelial Cell Notes
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Red Blood Cell Notes
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Levels of Organization in Multicellular Organisms

• Use the Levels of Organization webquest as notes
  for this section.

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Homeostasis in the Human Body

• Use the Homeostasis in the Human Body Webquest as
  notes for this section.

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The Cell Membrane

• Structure and Function
• Fluid Mosaic Model

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The Cell Membrane

• Regulates what enters and leaves
• Provides protection and support
• Made up of
• Phospholipids (lipid bilayer)
• Integral and Peripheral Proteins
• Carbohydrate chains (glycoproteins)
• Cholesterol

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Cell membrane structure
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Where are they found?

• Found in
• Nucleus
• Cell membrane
• Golgi apparatus
• endoplasmic reticulum
• lysosomes
• mitochondria
• (basically any membrane bound organelle!)

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Structure

• Lipid bilayer is made of the following
• 2 types of proteins
• Integral proteins
• Peripheral proteins
• 3 types of lipids
• Membrane Phospholipids
• Membrane glycolipids
• Cholesterol

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Integral proteins

• Transmembrane proteins (or integral proteins)
• Amphipathic hydrophobic and hydrophilic regions

25
Peripheral proteins

• Peripheral proteins
• linked at the cytoplasmic surface (by attachment
  to a fatty acid chain)
• linked at the external cell surface (attached by
  an oligosaccharide)
• may be bound to other membrane proteins

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Membrane Phospholipids

• These have a polar head group and two hydrocarbon
  tails
• It is connected by glycerol to two fatty acid
  tails
• One of the tails is a straight chain fatty acid
  (saturated). The other has a kink in the tail
  (unsaturated).

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Membrane glycolipids

• Glycolipids are also a constituent of membranes.
• These components of the membrane may be
  protective, insulators, and sites of receptor
  binding.

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Cholesterol

• The amount of cholesterol may vary with the type
  of membrane.
• Plasma membranes have nearly one cholesterol per
  phospholipid molecule.
• Other membranes (like those around bacteria) have
  no cholesterol

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Cholesterol (continued)

• Function
• This makes the lipid bilayer less deformable
• Without cholesterol (such as in a bacterium) a
  cell would need a cell wall.
• Also keeps the cell membrane from becoming too
  stiff.

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Fluid Mosaic Model

• Based on what you know about the structure and
  function of the cell membrane what does the fluid
  mosaic model mean?

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Diffusion, Osmosis, and Active Transport
Molecular Workbench Activity

• Complete this online and use your analysis
  packets as additional notes.
• We will be completing this in class!

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Movement Through the Membrane

• Materials can move through the membrane by
• Diffusion
• Osmosis
• Facilitated Diffusion
• Active Transport
• Protein Pumps
• Endocytosis
• Exocytosis

NO ENERGY (ATP) REQUIRED
high ? low
ENERGY (ATP) REQUIRED
low ? high
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Diffusion

• Requires no energy (ATP)
• Moves from an area of High concentration ? low
  concentration until dynamic equilibrium is
  reached.
• Dynamic equilibrium activity
• http//www.stolaf.edu/people/giannini/flashanimat/
  transport/diffusion.swf

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Osmosis

• A type of diffusion (no energy needed)
• Allows water molecules to pass easily through the
  selectively permeable membrane.
• Solution solute solvent
• Solute sugar (or another dissolved
  substance)CANNOT go through the membrane
• Solvent waterCAN go through the membrane

37
Osmosis

• ONLY water moves
• The solute stays put on one side or the other
• Water moves back and forth according to the
  concentration of water on each side of the
  membrane
• http//www.stolaf.edu/people/giannini/flashanimat/
  transport/osmosis.swf

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Osmotic Pressure

• Isotonic solutions
• The 2 solutions have equal concentrations of
  solute and solvent.
• Hypotonic solutions
• One solution has less solute and more water
  compared to the other solution.
• Hypertonic solutions
• One solution has more solute and less water
  compared to the other solution.

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What would happen?

• What would happen if
• You placed a selectively permeable membrane bag
  with a hypotonic solution into a beaker with a
  hypertonic solution?
• Which way would the water flow?
• What would happen to the bag?
• What would happen to the beaker?
• How do you know?
• How could you test this?

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Facilitated Diffusion

• Diffusion with the help of transport proteins
• No energy required
• http//www.stolaf.edu/people/giannini/flashanimat/
  transport/channel.swf

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Active Transport

• Cell uses energy
• Actively moves molecules to where they are needed
  
• Movement from an area of low concentration to an
  area of high concentration
• 3 MAIN TYPES
• Protein pumps
• Endocytosis (BULK TRANSPORT)
• Exocytosis (BULK TRANSPORT)

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Types of Active Transport

• 1. Protein Pumps -transport proteins that require
  energy to do work
• Example Sodium / Potassium Pumps are important
  in nerve responses.
• http//www.stolaf.edu/people/giannini/flashanimat/
  transport/secondary20active20transport.swf
• Protein changes shape to move molecules this
  requires energy!

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Types of Active Transport

• 2. Endocytosis taking bulky material into a cell
  
• Uses energy
• Cell membrane in-folds around food particle
• cell eating
• Forms food vacuole digests food
• This is how white blood cells eat bacteria!

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Types of Active Transport

• 3. Exocytosis Forces material out of cell in
  bulk
• membrane surrounding the material fuses with cell
  membrane
• Cell changes shape requires energy
• EX Hormones or wastes released from cell
• http//www.stolaf.edu/people/giannini/flashanimat/
  cellstructures/phagocitosis.swf

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Photosynthesis
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Energy and Life

• Energy ability to do work
• Source of energy on Earth sun
• Autotrophs ? use light energy from the sun (or
  other sources) to make food.
• Heterotrophs ?obtain energy from foods consumed.
• Energy comes in many forms
• Light, heat, and electricity

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ATP ? like a fully charged battery

• One of the principle chemical compounds that is
  used to store energy
• Adenosine triphosphate (ATP)

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ADP ? like a ½ charged battery

• When energy is released from ATP ? converts to
  ADP and a phosphate group

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Using Biochemical Energy

• Cells use this energy for
• Mechanical work, chemical work, transport work
• Basically, all cellular processes
• ATP in cells good for only a few seconds of
  activity (not efficient storage)
• 1 molecule of glucose stores more than 90xs the
  chemical energy of ATP
• Cells can generate ATP as needed from the glucose
  in carbohydrates consumed during feeding

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Investigating Photosynthesis

• Jan van Helmont
• Concludes plants gain most of their mass from
  water
• Joseph Priestly
• Concludes that plants release a substance that
  keeps a candle burning (oxygen)
• Jan Ingenhousz
• Concludes that plants produce oxygen bubbles in
  the light but not in the dark (they need
  sunlight).

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Photosynthesis Equation
53
Light and Pigments

• Photosynthesis requires
• Light
• From sunlight (A mixture of different wavelengths
  of light)
• Chlorophyll (a pigment found in chloroplasts that
  absorbs light energy)
• 2 main types
• Chlorophyll a (absorbs violet and red light)
• Chlorophyll b (absorbs blue and red light)

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Structure of a Chloroplast
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NADPH

• When sunlight hits chlorophyll a double bond is
  broken releasing a high energy electron.
• This high energy electron requires a special
  carrier called NADP.
• Once the electron is combined with NADP it
  becomes NADPH.
• NADPH carries this energy to other reactions
  around the cell.

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Light-Dependent Reactions

• Use energy from sunlight to produce Oxygen, ATP
  and NADPH.
• Photosystem II is the first to absorb light
  (discovered after photosystem I)
• Light smashes high energy electrons out of the
  chlorophyll molecules which are carried to
  electron transport chains in the thylakoid
  membrane.
• The lost electrons from the chlorophyll molecule
  are replaced by breaking water molecules apart
  which releases oxygen.

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Light-Dependent Reactions (Continued)

• High energy electrons move from Photosystem II to
  photosystem I.
• Energy from this transport pumps H ions from the
  stroma into the inner thylakoid.
• Pigments in photosystem I use sunlight to release
  additional high energy electrons and a H ion ?
  becomes NADPH
• Inside of thylakoid membrane becomes positively
  charged (from the H ions)/outside ? negatively
  charged
• Charge difference allows ATP to be made.

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Light-Dependent Reactions (Continued)

• ATP formation
• H ions move through a protein called ATP
  synthase.
• As it rotates the protein binds ADP with an
  additional phosphate to create ATP!

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The Calvin CycleOR the light-independent
reactions

• ATP and NADPH from the light reactions are
  required to produce high-energy sugars.
• Step 1 CO2 enters the cycle and is combined with
  6 5-Carbon molecules? forms 12 3-Carbon molecules
• Step 2 Energy from ATP and NADPH are used to
  convert the 12 3-Carbon molecules into
  higher-energy forms

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The Calvin CycleOR the light-independent
reactions

• Step 3 2 3-Carbon molecules are used to make a
  6-Carbon sugar (glucose!)
• Step 4 The 10 remaining 3-Carbon molecules are
  converted back into 6 5-carbon molecules
• These are reused in the next cycle!!!

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Factors affecting photosynthesis

• Availability of Water
• Shortage of water can slow or stop photosynthesis
• Temperature
• Plants function best between 0C and 35C
  (temperatures above or below may damage enzymes
  and slow or stop photosynthesis)
• Intensity of light
• Increasing intensity increases rate of
  photosynthesis until maximum rate of
  photosynthesis is reached.

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Photosynthesis Molecular Workbench

• We will be completing this online togetherUse
  your analysis packets as additional notes.
• We will be completing this in class!

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Cellular Respiration
67
Chemical Pathways

• Energy in food
• Calorie amount of energy needed to raise the
  temp. of 1 g of water 1C
• Gradually release energy from glucose and other
  food compounds
• 2 Pathway for energy release
• Aerobic (O2 present)
• Anaerobic (in the absence of O2)

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Cellular Respiration Overview

• Oxygen glucose ? carbon dioxide water
  energy
• 6O2 C6H12O6 ? 6CO2 6H2O ATP
• 3 main stages
• Glycolysis
• The Krebs cycle (or citric acid cycle)
• Electron Transport Chain (or oxidative
  phosphorylation)

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Glycolysis (glyco- sweet lysis breaking)

• Occurs in the cytoplasm near the mitochondion
• No oxygen is required for glycolysis
• 1 molecule of glucose (6C) is broken into 2
  molecules of pyruvic acid (3C) (pyruvate)
• Needs to use 2 ATP to get started
• Generates 4 ATP at the end
• Net ATP total 2 ATP
• Produces 4 molecules of NADH (high energy
  electron carrier) ? transports to other reaction
  sites

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What happens if there is no oxygen?

• Fermentation!
• Cells convert NADH back into NAD by passing
  electrons back to pyruvate
• Allows glycolysis to continue to produce ATP (not
  efficient)
• 2 main types
• Alcoholic Fermentation (bacteria and yeast)
• Lactic Acid Fermentation (humans)

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Alcoholic Fermentation

• Yeasts and bacteria
• Beer, wine, and bread production
• Pyruvic acid NADH ? alcohol CO2 NAD
• In bread
• CO2 makes the bread rise
• Alcohol is baked off

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Lactic Acid Fermentation

• Pyruvic acid is converted to lactic acid
• This regenerates NAD so glycolysis can continue
  to generate ATP
• Pyruvic acid NADH ? lactic acid NAD
• Produced in the muscles when there is not enough
  O2 causing burning/pain
• Example Wall sit of death

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What if there is oxygen present after glycolysis?

• Krebs cycle and electron transport chain!!!
• Most powerful electron acceptor oxygen!!!
• Uses the remaining 90 of energy still trapped in
  the glucose molecule after glycolysis!

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The Krebs Cycle

• Step 1
• Pyruvic acid enters the mitochodrion
• A carbon is removed forming CO2 and electrons are
  removed forming NADH
• CO2 is combined with coenzyme A and is
  transformed into acetyl-CoA
• Acetyl-CoA adds a 2-C acetyl group to a 4C
  compound forming citric acid.

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The Krebs Cycle (continued)

• Step 2
• Citric acid is broken down into a 5C compound
  then a 4C compound
• 2 molecules of CO2 are released, electrons form
  NADH and FADH2, and 1 ATP is generated
• From one molecule of pyruvic acid
• 4 NADH, 1 FADH2, 1 ATP
• But remember 2 molecules of pyruvic acid are made
  from each molecule of glucose!!! (so this
  process happens twice)

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Electron Transport

• The high energy electrons in FADH2 and NADH from
  the Krebs cycle
• Are transported to the inner membrane of the
  mitochondrion
• In prokaryotes ? ETC is in the cell membrane
• The ETC uses the high energy electrons to make
  ATP

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Electron Transport (continued)

• High energy electrons are passed to a series of
  carrier proteins in the membrane
• As electrons move to each carrier, H ions are
  moved to the inner membrane space
• These will be used later to generate ATP via ATP
  synthase
• At the end ? an enzyme that combines the
  electrons with hydrogen ions and oxygen to form
  water

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Energy Totals

• Aerobic Respiration 36 ATP
• Uses 38 of the total energy of a molecule of
  glucose
• The rest is released as heat (body heat!)
• More efficient than a gasoline car engine
• We are an efficient combustion engine!!!
• Anaerobic Respiration 2 ATP

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Energy and Exercise

• Quick energy ? (a sprint)
• ATP is short-lived and is used right away
• Stored ATP ? used in a few seconds of intense
  activity
• Then, ATP is generated via lactic acid
  fermentation

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Energy and Exercise

• Long-term energy ? (marathon)
• For exercise longer than 90 seconds ? cellular
  respiration is the only way to generate enough
  ATP to sustain activity.
• Stored energy glycogen (breaks down into
  glucose and is stored in muscles)
• Lasts only about 15-20 minutes
• Once glycogen is depleted ? body uses fat stores
  (good for weight loss!)

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Linking to Homeostasis

• How does cellular respiration work to maintain
  homeostasis in the human body? Include body
  systems in your response.

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Comparing Cellular Respiration to Photosynthesis

• Generate a chart comparing the following

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Cellular Respiration Molecular Workbench

• Complete this online and use your analysis
  packets as additional notes.
• We will be completing this in class!

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Cell Growth and Division
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Limits to Cell Size Activity

• Draw an example of a town with the borders being
  the edges of the paper
• There are 2 main roads into and out of the town.
• Think of a cell and the parts needed to run the
  cell.
• Recreate these parts as parts of a town
• Dont forget nutrients (food trucks) and waste
  (dump trucks)

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Limits to Cell Size Activity

• Increase the Population
• What does this do to the demands put on the
  town?
• What does this do to the Traffic?
• What does this do to the Waste and Nutrients?
• What does this do to the Resources needed to
  thrive?
• What does this do to the people who run the town?

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Limits to Cell Size Activity

• Based on the activity
• What are the 2 limits to cell size?
• What happens when a cell becomes too big?

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Cell Growth

• 2 limits to cell size
• The larger the cell becomes the more demands the
  cell places on its DNA
• The cell has difficulty moving nutrients and
  waste across the membrane
• Thus the size of a cell is limited
• As the length of a cell increases
• Volume increases faster than its surface area

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What happens when a cell gets too big?

• IT DIVIDES!!!
• Cell division
• 1 cell ? 2 daughter cells (exact copies of the
  original)
• Prokaryotes ? easy
• Circular DNA ? copies then divides
• Eukaryotes ? more involved
• Complex DNA (23 pairs of chromosomes 46 total)

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The Cell Cycle

• Average time
• 16 20 hours

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G1 Phase

• Cell Growth
• Intense growth and activity
• Increases in size
• Synthesizes new proteins and organelles

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The Cell Cycle
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S Phase

• DNA Synthesis
• Creates a duplicate set of chromosomes
• G0 (or R on diagram) Point of no return

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Chromosome Structure
supercoils
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Human Chromosomes (Karyotype)
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The Cell Cycle
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G2 Phase

• Preparation for Mitosis
• Shortest of the 3 phases of interphase (G1, S,
  and Gs)
• Organelles and proteins needed for cell division
  are produced.

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The Cell Cycle
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Mitosis

• Prophase
• Metaphase
• Anaphase
• Telophase
• Cytokinesis

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Prophase

• Chromosomes condense (appear)
• Nuclear envelope dissolves
• Centrioles move to opposite sides (poles) of the
  cell

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Metaphase

• Centrioles send out spindle fibers that attach to
  the chromosomes
• Chromosomes are lined up in the middle of the cell

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Anaphase

• Chromosomes (sister chromatids) are pulled apart
  and move to the poles.

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Telophase/Cytokinesis

• Occurs simultaneously
• Telophase
• The nuclear envelope reforms around the
  chromosomes
• The chromosomes uncoil
• Cytokinesis
• The cytoplasm divides
• 2 daughter cells are produced (each are exact
  copies of the original with 46 chromosomes)

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What stages are these cells in?
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Investigating Cell Reproduction

• Complete the lab activity
• Paper lab

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GO TO Meiosis PowerPoint
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Regulating the Cell Cycle
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Controls on Cell Division

• Cell growth and division can be turned on and off
• Example
• Cells in a petri dish will continue to grow until
  they come in contact with other cells.
• A cut in the skin will cause cells to divide
  until the wound in healed.

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Cell Cycle Regulators

• Cyclin
• Protein that regulates the cell cycle in
  eukaryotic cells
• When injected into a non-dividing cell it causes
  a mitotic spindle to form
• Internal Regulators
• Responds to events inside the cell
• Makes sure that a cell does not enter mitosis
  until all chromosomes are replicated

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Cell Cycle Regulators (cont.)

• External Regulators
• Respond to events outside the cell
• Growth factors that speed up or slow down
  growth and division

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Uncontrolled Cell Growth

• CANCER
• Cells that lose the ability to control cell
  growth
• Most cancers have damage to the p53 gene
• Normally halts the cell cycle until all
  chromosomes are replicated
• Chromosome damage builds up and the cancer cell
  loses the information that controls normal cell
  growth
• Tumors ? masses of cells that can damage the
  surrounding tissue
• CAUSES smoking tobacco, radiation exposure (UV,
  XRAY, etc.), viral infection

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Life Spans of Various Human Cells
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Life Spans of Human Cell Questions

• White blood cells help protect the body from
  infection and disease-producing organisms. How
  might their function relate to their life span?
• If cancer cells were added to the table, predict
  what would be written under the Life Span and
  Cell Division columns. Explain youre the
  reasoning behind your predictions.

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EXTRA CREDIT

• Write a 1 page (double-spaced) description of
  the latest research on cancer.
• WORTH 10 Points!!!
• Due Friday!!!