Test #2February 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 nucleuso Binary Fission DNA replication Cell growth Two daughter cellsFigure 12-12 for Binary fission in Prokaryotes- Eukaryotes- FIGURE 6-8 o Mitosis and cytokinesisDefine:- Chromatino dna + protein… all the dna in the nucleus and how it is wrapped up with proteins- Chromosome- Sister chromatido When two chromosomes have the exact same genetic DNA- Centromereo Where two chromosomes can be held togethero Proteins inside are what help hold the chromosomes together- Centrioleo Made up of microtubules…. o Centriole + spindle = centrosomeo Structures can be identified by microscopeo Function Unknown- Centrosomeo Region that organizes the centrioles and other microtubules- Kinetochoreo Proteins at centromere that interact with spindle microtubules- Mitosiso Dividing nucleus and genetic material- Cytokinesiso diving the rest of the cell and cytoplasmThe Cell Cycle- Are all cells dividing? NO. o G0- When a cell will no longer divideo Interphase is the majority of the cell cycleo 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 mitosiso Mitotic phase – if the cell cannot undergo division after g2 it will go back and prepare for mitosiso 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 chromosomesCytokinesis- diving the rest of the cell and cytoplasm- Animal Cellso 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 cellso Cell plate cell wall + plasma membraneo Vesicles derived from GolgiEach 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)- Signalso Accumulation of specific types of proteins (cyclins)o Different cyclins for different checkpoints- G2 CHECKPOINT (in order to go to mitosis)o Cyclin protein accumulateso Interacts with cdk enzymeo Forms mitosis promoting factor (mdf)o Mitosis initiatedCancer: Uncontrolled cell division- No checkpoints- Non-stop mitosis creates tumors- No density-dependent inhibition- Tumors can spread to other parts of body= metastasisLook at Figure 12-20 for the growth and metastasis of a tumor- Metsastis:o Tumor grows from a single cancer cello Cancer cells invade neighboring tissueo Cancer cells spread to other parts of the bodyo Cancer cells may survive and establish a new tumorFebruary 11, 2014 Chapter 8Metabolism- Energyo The capacity to do work or cause changeo If you break down matter it releases ENERGY… (same thing..diff forms)o E=MC^2o Types of Energy Kinetic- Energy due to motion- Ex: light, heat, sound Potential- Energy stored due to position or structure- Ex: chemical, atomico 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 2-13-14o Energy Flow in natural systems Fig 9.2- Thermodynamics- studying energy flow in natural systems 1st law- Energy and matter cannot be created or destroyed, only transferred 2nd 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
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