Biology Cell transport and cell cycle 12 / 06 / 12 Thursday
Cell Transportation Mr. Hunter BiologyKennedy High School 09/28/2011
Mr. Hunter Biology• Objective(s)• SWBAT• Distinguish between diffusion and osmosis• Explain how substances cross the cell membrane.• Explain the function of ion channels.
DiffusionA. The movement of particles from a high concentration to a low concentration.B. The process is passive. It does not require energy.C. Diffusion will continue until an equilibrium point has been reached.
OSMOSIS A. Osmosis can be described as the diffusion of water across a selectively permeable membrane. B. Water will flow from a region of low solute (particles that are dissolved in a solution – ex. salt or sugar ) to a region of high solute concentration. C. Water will always move in a direction to dissolve the higher concentration of particles. • Remember – A solute is what is being dissolved. • A solvent – dissolves the solute. • A solution – contains both the solute and solvent.
Facilitated Diffusion• This process is used for molecules that cannot easily diffuse through the cell membrane• These molecules may be insoluble in lipids or they may be too large to pass through the pores of the membrane.
Facilitated Diffusion• The movement of the molecules are assisted by carrier proteins –Specific• These are specific proteins within the cell membrane.• Facilitated diffusion is a passive process. It does not require energy – moving molecules down the concentration gradient.• Glucose has to be transported by facilitated diffusion – molecule is large.
Ion Channels• Ion channels transport ions from high to low concentration. Examples: Na+, K+ and Cl-.• Some ion channels are always open others may have gates which may open or close in response to stretching of the membrane, electrical or chemical signals.
Active Transport• Active transport requires energy because you are going against the concentration gradient.• The molecules are moving from a low to high concentration.
Na+ and K+ pump• The Sodium-Potassium pump is required for moving Na+ and K+ up their concentration gradients.• To function normally some animals must have a higher concentration of Na+ outside the cell and K+ inside of the cell.
Na+ and K+ pump• The exchange of three Na+ ions for two K+ ions creates an electrical gradient across the cell membrane. The outside of the cell is + relative to the inside which is -.
Endocytosis and Exocytosis• Endocytosis means in which cells ingest external molecules.• Pinocytosis: cell will ingest liquids• Phagocytosis: Cell will ingest solids / large particles.• Exocytosis is the opposite.
Review Questions –Cornell No Talking During Review / Question Assignment!1. What type of molecules are carried by facilitated diffusion?2. What are the name of the structures that carry molecules across the membrane in facilitated diffusion?3. Will these structures carry all molecules?4. What is the function of an ion channel?5. Why does active transport require energy?6. Explain how the sodium-potassium pump works.7. Describe endocytosis and exocytosis.
Mr. Hunter Biology 12/12/2011• Objective(s)• SWBAT• Describe the structure of a chromosome• Identify differences in chromosome structure• Describe the events in cell division.
Bell Ringer 12/12/20111. What is the independent and dependent variable?2. Approximately how many cells are produced in 20 minutes?3. 22 cells are produced in approximately how many minutes?
Chromosome Structure• Chromosomes: rod Chromosomes shaped structures made of DNA and protein.• The DNA in eukaryotic cells wrap around proteins called histones. These proteins help to maintain chromosome shape and DNA packing.
Chromosome Structure• Each half of the chromosome is called a chromatid. Chromatids form as the DNA makes a copy of itself before cell division.• When the cell divides, each of the new cells will receive one chromatid from each chromosome.
Chromosome Structure• The two chromatids of a chromosome are attached at the centomere region. The centomere holds the two together until they separate during cell division.• When a cell is not dividing, DNA is uncoiled in the form of chromatin.• Prokaryotic DNA consists of one chromosome which is circular.
Chromosome Type and Number• Each species has a characteristic number of chromosomes in each cell. (Table 8-1)• Human and animal chromosomes are characterized as either sex chromosomes or autosomes.• Sex chromosomes: X and Y. Females XX, Males XY
Chromosome Type and Number• 2 sex chromosomes and the remaining 44 are autosomes. Total = 46 chromosomes.• Homologous chromosomes are of the same size and shape and carry genes for the same traits. A homologue is received from each parent. 22 pairs of homologous chromosomes and 2 sex chromosomes.
Chromosome Type and Number• Karyotype: picture of chromosomes in a normally dividing cell.• Diploid chromosome # is 46 chromosomes total.• Haploid chromosome # is 23 chromosomes total.
Mr. Hunter Biology 12/20/2011• Objective(s)• SWBAT• Compare the stages of mitosis with meiosis.• Explain the concept of crossing over between homologous chromosomes.• Determine the function of cell cycle checkpoints.• Above via Chapter Study Guide Review A / B
Bell Ringer 12/13/20111. What are the dependent and independent variables?2. At approximately 2 hours of use, what was the highest voltage of the Panasonic battery?3. Which battery had the value 0.800 volts at approximately 9 hours of use?
Bell Ringer 12/19/20111. What are the dependent and independent variables?2. In what month was the value of product X approx.3. $15,000?4. In what month was the value of product Y the highest?5. In Which month did product X have the highest value?
Bell Ringer 01/20/20121. What are the dependent and independent variables?2. In which month were sales approx. $350?3. In which month were sales reported to be the lowest?4. What was the lowest recorded approximate value for profits?
Bell Ringer 01/19/20121. What are the dependent and independent variables?2. When the pressure is 300, the approximate temperature for the blue liquid is ____3. When the red liquid’s pressure is 400, the temperature is approximately __________
Biology Assignment 01/09/2012 pg. 164 (new edition) pg. 155-156 (old edition) Due @ end of Class!!• Compare and Contrast Sperm formation and Ovum formation.• Where does each occur?• When does each process take place?• What is the duration of each process?• How many cells and types (haploid or diploid) are produced by each process?• * Information should be presented in a• T-chart or table format *
PROKARYOTIC CELL DIVISION• Prokaryotic cells lack nuclei and membrane bound organelles.• Prokaryotic DNA is not associated with proteins. It is a single circle attached to the inner surface of the plasma membrane.• Prokaryotic cells reproduce by binary fission.
Cell Division• In eukaryotic cell division , the cytoplasm and the nucleus will divide.• Two types of cell division for eukaryotic cells: Mitosis and Meiosis• What structures divide in eukaryotic cell division?
Cell Division• Mitosis results in new cells that has identical genetic material as the original cell.• Mitosis occurs in organisms undergoing growth, development, repair or asexual reproduction.• What type of organisms will mitosis occur in?• What type of genetic material do the cells of mitosis have?
Cell Division• Meiosis occurs during the formation of gametes.• Gametes are haploid reproductive cells, the egg and sperm cells.• Meiosis reduces the chromosome number by ½. Ex. 23 + 23 = 46• 2n = diploid, 1n = haploid
The Cell Cycle• A repeating set of events in the life of a cell.• Cell division is one phase of the cell cycle.• The time between cell divisions is called interphase. The cell spends 90% of time here.
The Cell Cycle• The chromosomes and cytoplasm are equally divided between two offspring cells.• Cell divisions consists of mitosis and cytokinesis• During mitosis, the nucleus of the cell divides.• During cytokinesis, the cytoplasm divides.• What structures divide in mitosis and cytokinesis?
Cell Cycle Checkpoints• Checkpoints are proteins that act as traffic signals for the cell cycle.• G1 checkpoint: Proteins check has the cell grown enough to start cell division. G1 proteins will allow DNA replication to occur.
Cell Cycle Checkpoints• DNA synthesis (G2) checkpoint: DNA repair checkpoint enzymes check the results of DNA replication. If this checkpoint is passed the cell will divide by mitosis.
Cell Cycle Checkpoints• Mitosis Checkpoint: If the cell passes this checkpoint, then the proteins signal the cell to exit mitosis.• The cell then enters the G1 phase of the cycle.• Cancer may result from a malfunction of the proteins that control the cell cycle.
Homologous Chromosomes and Crossing Over• During Prophase I of Meiosis portions of homologous -chromosomes exchange genetic information with each other.• This leads to increased genetic variability (genetic recombination) among the offspring.
Meiosis I and Meiosis IIMeiosis: An Interactive Animation
Class Assignment• Pg. 166 Understanding Key Concepts # 15-20 Cornell Note Format Due @ end of Class!!!• Critical Thinking: # 23-25 Answer in complete sentences. Due @ end of class!!!• Complete Study Guide Review Questions !!
Assignment Mr. Hunter Biology• Construct Cornell Notes for the following pages: 155-157. Due @ end of class!!• Notes should be made for the topics of :• The Cell Cycle• Interphase• Stages of Mitosis: prophase, metaphse,anaphase and telophase)• Cytokinesis
Assignment Mr. Hunter Biology• Answer Review Questions in Cornell Note Format. Pg. 159 # 1-9• Sketch and color fig 8-4, fig 8-5 & fig.8-6 Explain what is occurring in each figure and each stage of the cell cycle and each stage of Mitosis. PMAT in detail.• Due @ end of class!!!
Mr. Hunter Biology Assignment 12/14/2011• Cell Cycle and Mitosis Worksheets.• Pg. 166 # 1-2, 5-14 – Cornell Note Format for #s 5-14!!• Due @ end of Class!
Active and Passive Transport Quiz 12/08/20111. Describe the process of diffusion in terms of movement of molecules within a concentration gradient.2. What is the function of a carrier protein?3. What are the differences / similarities between facilitated diffusion and simple diffusion?4. What determines if a molecule will go through the process of facilitated diffusion.5. Why does active transport require energy and facilitated diffusion does not? What provides the energy for active transport?6. Explain how the sodium-potassium pump works.7. What are the concentrations of Na+ and K+ .
Bell Ringer 09/28/2011• A scientist performed an experiment testing the acidity of a new compound. He added drops of the new compound to 3 different beakers containing water. He then measured the acidity of the solutions (compound mixed with water) with a pH meter and graphed the results.• What is the independent variable?• What is the dependent variable?• What is a possible control group?• What is the experimental group?
Bell Ringer 9/29/2011• You are the manager of a large pharmaceutical research team. You have just developed a new drug (Dioxitropine) that attacks cancer cells in young adults. You are approved to test your drug on the following groups: A – received new drug, B: -received a sugar pill, C: received new drug and additional cancer treatments. The number of cancer cells in Group C decreased the most. The number for A was unchanged.• What is the independent variable?• What is the dependent variable?• Which group is the control group?• What possible control factor(s) could you think of for Group C that could decrease errors in the experiment?• What is a possible hypothesis for the experiment?
Bell Ringer 09/30/2011As a scientist you are presented with an experiment with three plants and a new fertilizer. Fertilizer X was added to plant A. Fertilizer X was added to plant B. and Fertilizer X was not added to plant C. Plants A and B showed the most measured growth.1. What is the independent variable?2. What is the dependent variable / control ?3. What is the hypothesis of the experiment?
BELL RINGER 10/05/2011• CREATE A GRAPH SKETCH OF THE FOLLOWING DATA. - TURN IN ON NOTEBOOK PAPER RATE (Sec) TEMPERATURE (CELSIUS) 40 20 30 30 20 40 10 50 What is the independent variable/ dependent? What axis does the independent / dependent belong?What does the line of the graph look like?
A. In an SEM, the electron beam is focusedScanning electron on a specimen coated with a thin layer ofmicroscope metal. The electrons that bounce off the specimen form an image on a fluorescent screen. B. An SEM shows three-dimensional images of cell surfaces. C. As in the TEM, the specimens are not living when viewed under SEM. D. The scanning tunneling microscope, STM uses a needle-like probe to measure differences in voltage caused by electrons that leak, or tunnel from the surface of the object being viewed. E. A computer tracks the movement of the probe across the object and generates a three-dimensional image of the specimen’s surface – STM used on living organisms.
A. In 1838, the German botanist Mattias Schleiden concluded that cells composeThe Cell – Theory and every part of the plant.Features B. A year later, the German zoologist Theodore Schwann claimed that animals are also made of cells. C. In 1858, Rudoloph Virchow, a German physician, determined that cells come from other cells. D. The works of these three scientist form the Cell Theory 1. All living things are made of one or more cells. 2. Cells are the basic units of structure and function in organisms. 3. All cells arise from existing cells.