Test 2 February 4 2014 Pages 228 236 239 243 Chapter 12 Cell division and the Cell Cycle Why do cells need to divide Where do cells divide o Skin blood cells brain cells white blood cells the cells that line your gut etc What is the end result of cell division o The process of mitosis is to produce two genetically IDENTICAL cells Prokaryotes FIGURE 12 11 o Pro before nucleus o Binary Fission DNA replication Cell growth Two daughter cells Figure 12 12 for Binary fission in Prokaryotes Eukaryotes FIGURE 6 8 o Mitosis and cytokinesis Define Chromatin o dna protein all the dna in the nucleus and how it is wrapped up with proteins Chromosome Sister chromatid o When two chromosomes have the exact same genetic DNA Centromere o Where two chromosomes can be held together o Proteins inside are what help hold the chromosomes together Centriole o Made up of microtubules o Centriole spindle centrosome o Structures can be identified by microscope o Function Unknown Centrosome o Region that organizes the centrioles and other microtubules Kinetochore o Proteins at centromere that interact with spindle microtubules Mitosis o Dividing nucleus and genetic material Cytokinesis o diving the rest of the cell and cytoplasm The Cell Cycle Are all cells dividing NO o G0 When a cell will no longer divide o Interphase is the majority of the cell cycle o Interphase time spent PREPARING to divide G1 First growth phase first gap Cell is preparing to be able to undergo DNA synthesis Increasing cytoplasm volume of cell S Synthesis production of DNA Dna is replicated G2 Second growth phase Makes sure cell has everything ready so it can undergo division Microtubules are produced Occurs RIGHT before mitosis o Mitotic phase if the cell cannot undergo division after g2 it will go back and prepare for mitosis o Mitosis Dividing nucleus and genetic material Prophase Chromosomes are just beginning to condense get more compact Spindle is made of microtubules Pro metaphase Clearly condensed chromosomes Interact with spindle Nuclear envelope still exists Metaphase Chromosomes line up in cell on metaphase plate Nuclear envelope has disappeared Chromosomes attached to spindle fibers Anaphase Chromosomes are pulled apart to opposite poles of the cell Spindle fibers pull chromosomes apart to opposite poles Each new cell has 1 copy of each type of chromosome Telophase Chromosomes begin to unravel and de condense Nucleus reforms around chromosomes Microtubules of spindle disperse to become parts of other things Look at figure 12 7 for the stages of Mitosis and be able to follow the nuclear envelope spindle apparatus and chromosomes Cytokinesis diving the rest of the cell and cytoplasm Animal Cells o Cleavage furrow pinches to divide Microfilaments actin and myosin to form circles that slowly get smaller until you have two different cells on either side Plant cells o Cell plate cell wall plasma membrane o Vesicles derived from Golgi Each vesicles have a cell membrane and cell wall They eventually diffuse to form one solid plate which will fuse to older plates to form a wall Control of the Cell Cycle Checkpoints border crossings Signals o Accumulation of specific types of proteins cyclins o Different cyclins for different checkpoints G2 CHECKPOINT in order to go to mitosis o Cyclin protein accumulates o Interacts with cdk enzyme o Forms mitosis promoting factor mdf o Mitosis initiated Cancer Uncontrolled cell division No checkpoints Non stop mitosis creates tumors No density dependent inhibition Tumors can spread to other parts of body metastasis Look at Figure 12 20 for the growth and metastasis of a tumor Metsastis o Tumor grows from a single cancer cell o Cancer cells invade neighboring tissue o Cancer cells spread to other parts of the body o Cancer cells may survive and establish a new tumor February 11 2014 Chapter 8 Metabolism Energy o The capacity to do work or cause change o If you break down matter it releases ENERGY same thing diff forms o E MC 2 o Types of Energy Kinetic Energy due to motion Ex light heat sound Potential Energy stored due to position or structure Ex chemical atomic o Measuring Energy Calorie cal amt heat required to raise 1 g of water 1 C Kcal 1000 cal calorie in food Measure calories in a calorimeter Enzymes Chemical reactions Matter elements atoms Electron movements Concentration gradient How are they related The Big Picture Energy flow and chemical recycling in ecosystems FIGURE 9 2 2 13 14 o Energy Flow in natural systems Fig 9 2 Thermodynamics studying energy flow in natural systems 1 law Energy and matter cannot be created or destroyed only transferred st 2 law In energy transfer some energy becomes unusable heat which increases entropy or disorder of the universe Spontaneous Reactions exergonic Require no input of energy Increases entropy Spontaneous doesn t equal instantaneous Do you have to measure the entropy of the entire universe to determine if a reaction will be spontaneous NO Gibbs Free Energy Measures the energy in a system ex living cell Value of delta G will predict spontaneity of a reaction Delta G delta H TdeltaS Delta G change in entropy E available for work Delta H change in enthalpy potential E T temperature measured in Kelvin Delta S change in entropy Negative delta G spontaneous Exergonic net release of free energy products are more stable but with less free energy Positive delta G not spontaneous Endergonic absorbs stores free energy products are less stable but with more free energy than the reactants Fig 8 5 Metabolism Chemical reactions in a cell required to maintain life Types of metabolism Anabolic building molecules requires energy Catabolic breaking down molecules If in a closed system nothing comes in or out it keeps going until equilibrium Cells are open systems things come in and out never reaching equilibrium if it does we will die Ha Metabolic disequilibrium When reversible reactions are pulled in one direction due to the constant flow of material in and out of the cell Enzymes Catalyst proteins not consumed in reaction Active site Have precise physical shape for specific reactants substrates Site of catalyst provides microenvironment Changes shape to form induced fit Applies force to break bonds form new bonds Fig 8 14 Rates of reactions vary nd Enzyme concentration Positive slope until plateaus caused by a lack of substrate Substrate concentration Positive slope until plateaus caused by a lack of enzymes Temperature pH Cofactors non protein molecules aid
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