Transcript Diffusion
http://images.search.yahoo.com/images/view;_ylt=AwrTcXaFSRJTLHwApHmJzbkF;_ylu=X3oDMTIyN3Mwa2pkBHNlYwNzcgRzbGsDaW1nBG9pZANkZWRmN2ZjODZjNzQyYjk3MmE4ODcwODU2OTM1NmEzNARncG9zAzEEaXQDYmluZw--?back=http%3A%2F%2Fimages.search.yahoo.com%2Fyhs%2Fsearch%3F_adv_prop%3Dimage%26va%3Dmonday%2Bblues%2Bfunny%26fr%3Dyhs-w3i-geneiotransfer%26hsimp%3Dyhs-geneiotransfer%26hspart%3Dw3i%26tab%3Dorganic%26ri%3D1&w=400&h=322&imgurl=bp3.blogger.com%2F_D-LZxhXlNXY%2FRlq47SWqq_I%2FAAAAAAAAAHI%2F0w4rwWA2WVQ%2Fs400%2FShowLetter.jpg&rurl=http%3A%2F%2Fhumor-in-photos-and-pictures.blogspot.com%2F2007%2F05%2Fmonday-morningblues.html&size=41.6KB&name=ShowLetter.jpg&p=monday+blues+funny&oid=dedf7fc86c742b972a88708569356a34&fr2=&fr=yhs-w3i-geneiotransfer&tt=ShowLetter.jpg&b=0&ni=128&no=1&ts=&tab=organic&sigr=12ikm7jr8&sigb=14u0e2dcq&sigi=12k6i1mc0&.crumb=XgXRdUZNbqv&fr=yhs-w3i-geneiotransfer&hsimp=yhs-geneiotransfer&hspart=w3i# Cell Analogy is due today!!!!!!!!!!!!!!!!!!!! Check the Website ●Answer Key’s for: ○Organic Molecules ○Guided Notes ○Don’t forget about the study guide Reflect and Connect pg 303 #1-3 ●1. Draw a series of sketches to illustrate important stages of the cell cycle and mitosis. Your drawing should include: ○ Include a starting cell with genetic material represented by two pairs of chromosomes ○ Include a nucleus with the appropriate chromosomes in each of the cells ○ Indicate with a flowchart or sketches the genetic material is duplicated (DNA synthesis) ○ Show the cells formed as a result Cell wall Chromosome pairs Nucleus Reflect and Connect pg 303 #1-3 DNA Replication Parent Cell daughter Cell Reflect and Connect pg 303 #1-3 ●2. Why is it important that DNA (chromosomes) duplicates before mitosis? All cells within an organism contain the same genetic information. The genetic materials must duplicate for both of the daughter cells to contain the same genetic information as the parent cell ●3. Describe why cell division is an important process for all organisms? Cell division is important for: • replicating old worn out cells • is needed for the growth of plants and animals and • Is needed to produce specialized cells for plants/animals Define Diffusion The movement of molecules from a area in which they are highly concentrated to a area in which they are less concentrated. https://www.youtube.com/watch?v=4ZKBeEvmqzI Example of Diffusion. Concentration Gradient ○The concentrations of molecules at various points separate high concentrations from low create a boundary called a concentration gradient. Low Concentration High Concentration Concentration Gradient There is a concentration gradient because of the differences in concentration Down or Up Gradient? • Down a concentration gradient • HIGH concentrated to LOW concentrated • Happens automatically without any energy added • Sound familiar? (Diffusion) • Up a concentration gradient • LOW to HIGH concentration • Requires energy Diffusion and Cells Diffusion: nutrients and materials through the cell http://www.mrcorfe.com/KS4/Edexcel/Biology/B2-1-LivingCells/images/DiffusionCell.jpg Define Osmosis The diffusion of water across a selectively permeable membrane. http://trendliest.files.wordpress.com/2008/09/1b442cec-5d9e-4d51-89ff7b3e0ab55e9a_450.jpg Osmosis in Cells ●Affects the size and shape of cells, by the amount of water/solutes across the membrane. ●Gain/loss "pressure" like miniature balloons. ●Solute: dissolved substance: a substance dissolved in another substance ●Hypertonic: kids are hyper kick them out ●Hypotonic: “hypo” prefix means under ●Isotonic: “iso” prefix means equal Osmosis in Cells ●Hypertonic concentration of solutes is greater outside the cell than inside ●Hypotonic: Concentration of solutes is greater inside the cell than outside ●Isotonic: Concentration is equal http://legacy.hopkinsville.kctcs.edu/sitecore/instructors/Jason-Arnold/VLI/Module%202/m2cellfunctionandenergetics/f513_osmosis_in_animal_c.jpg Define Selectively Permeable Membrane ●A membrane that allows only certain materials to cross it ●Materials pass through pores in the membrane Why Are Osmosis & Diffusion Important? ●All living things have certain requirements they must satisfy in order to remain alive ○exchanging gases (usually CO2 and O2) ○taking in water, minerals, and food, ○eliminating wastes. ●These tasks happen at the cellular level. ●Molecules move through the cell membrane by diffusion Active versus Passive Transport • Are biological processes that move oxygen, water, and nutrients into cells and remove waste products. Active versus Passive Transport Active versus Passive Transport Passive transport: Active transport: • Moves molecules from • Requires ENERGY areas of HIGH because it is the concentration to areas of movement of molecules LOW concentration; so from areas of LOW it DOES NOT require concentration to areas of energy. HIGH concentration. • Diffusion • Uses Protein synthesis to aid • Osmosis • Facilitated Diffusion Active versus Passive Transport Glucose • Cannot move easily because it is large. But can pass through with Passive Transport with the facilitated diffusion Water • Can move easily because it is small. Uses Osmosis, which is Passive Transport Oxygen • Can move easily because it is small and moves through diffusion (Passive Transport) Sodium • Use Active Transport, requiring Energy to move against the concentration gradient as well as with it Cell Cycle Why must cells divide in order to grow? Why is this so important? ○to reach maximum efficiency for molecular transport, and maintain the functions of the cell. ○limits to how large a cell can become, so when those limits are reached the cells divide. ○replace old cells that are worn down or damaged ○differentiation in multicellular organisms to become different in appearance and function Mitosis ●Is the precise distribution of DNA to daughter cells ○IPMAT Differentiation ●Differentiation: ○new cells specialize and become different in appearance and function from their parent cells. ○become specialized according to a genetically determined plan ○Occurs as a result of a combination of signals that cause different cells to activate different portions of their genetic information ○Differences in how cells look & behave reflect differences in how they use the genetic information they have Mitosis: Interphase ●Interphase: ○Long and active cycle ○DNA and chromosomes are duplicated in the nucleus ○Mitochondria are made in the cytoplasm ○Cell grows Mitosis: Prophase ●Prophase: ○ Chromosomes coil & shorten. ○ Each Chromosome appears as a double structure joined at the centromere ○ Centrioles move to opposite ends of the cell (except in plants, there are no centrioles, but these events still occur as described here) Mitosis: Metaphase Metaphase: ●Doubled chromosomes line up ●Cytoplasmic fibers are now attached to each doubled chromosome at the centromere Mitosis: Anaphase Anaphase: ●Doubled chromosomes separate ●New chromosomes are pushed and pulled to the opposite ends of the cell by the cytoplasmic fibers Mitosis: Telophase Telophase: ●Chromosomes approach the ends and group together ●New nuclear membrane ●Cytoplasm divides ●New cell membrane forms (cell wall laid between new cells in plants) ●The new cells enter interphase How is the DNA of a parent cell and daughter cell related in mitosis? ●There is absolutely no difference in DNA between the parent cell and daughter cell in mitosis. During mitosis, the DNA is copied exactly and transferred, so the DNA is exactly the same in both cells.