BSC108- Exam 2
Popular in Intro to Biology
Popular in Department
This 10 page Study Guide was uploaded by Leah Larabee on Tuesday February 17, 2015. The Study Guide belongs to BSC 108 at University of Alabama - Tuscaloosa taught by Dr. Yates in Spring2015. Since its upload, it has received 560 views.
Reviews for BSC108- Exam 2
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/17/15
CH5 Thermodynamics the study of energy Calorie is the amount of energy that raises the temperature of one gram of water by one degree Celsius ocalories are very small units of energy Not practical for measuring the energy in food 0A food calorie capitol C is actually a kilocalorie 1000 calories oAbout 40 of the energy in food is transferred to ATP The remainder becomes heat oScientists use the term entropy as a measure of disorder or randomness All energy conversions increase the entropy of the universe Laws of Theromydamics 1st law energy can be transformed changed from one form to another but it can neither be created nor destroyed 2nd law entropy of an isolated system which is not in equilibrium will tend to increase over time approaching a maximum value at equilibrium Entropy means disorder or chaos ATP is the energy currency in all cells oActivation energy 15 the energy that activates the reactants in a chemical reaction Triggers a chemical reaction to proceed oEnzymes Lower the activation energy for chemical reactions oEnzyme inhibitors Can inhibit a metabolic reaction Some bind to the active site as substrate imposters Bind at a remote site changing the enzyme s sha e 1 oEach enzyme 15 very select1ve Induced Flt It catalyzes spec1f1c react10ns Subsquota esquot 39 5 oEach enzyme recognizes a specific 0 Sucrase can accept a H Active site molecule of its substrate SUbStI ate Fl Substrate binds 39 39 39 etotheenzyma The act1ve SIte ts to the substrate and the enzyme Enzyme changes shape slightly This interaction is called induced fit sucrase Fructose C 6 oEnzymes can function over and Glucose over again 9 Theenzyme Th1s 1s a key character1st1c catalyzes the of enzymes chemical reaction 0 The products are released Passive Transport Diffusion Across Membranes oDiffusion is one result of the movement of molecules Molecules tend to spread into the available space Diffusion is passive transport no energy is needed oAnother type of passive transport is facilitated diffusion the transport of some substances by specific transport proteins that act as selective corridors Osmosis is the passive transport of water across a selectively permeable membrane Hypommc Hypertonic oA hypertonic solution solution solution Isotonic so39utions Has a higher concentration of solute oA hypotonic solution Has a lower concentration of solute oAn isotonic solution Sugar molecule Has an equal concentrat10n of solute Selectively permeable SOIUte membrane 0smoregulatlon1s the control of water 03mm balance in animals net movement of water oWater balance in plant cells is different They have rigid cell walls They are at the mercy of the environment oActive transport requires energy to move molecules across a membrane oExocytosis Secretes substances outside of the cell oEndocytosis Takes material into the cell 0 Phagocytosis quotcellular eating a cell engulfs a particle and packages it within a food vacuole oPinoc osis quotcellular drinking a cell gulps a Botanic b Hypotonic c Hypertonic droplets of uid by forming tiny vesicles cob rm colquotinn colquotinn oReceptormediated endocytosis Is triggered by the binding of external molecules to membrane proteins CH6 Plants and other autotrophs selffeeders oMake their own organic matter from inorganic nutrients oAutotrophs are producers because ecosystems depend upon them for food Heterotro hs otherfeeders Turgid oInclude humans and other animals that cannot make organic molecules from inorganic ones oHeterotrophs are consumers because they eat plants or other animals Plant and animal cells perform cellular respiration a chemical process that o Primarily occurs in mitochondria o Harvests energy stored in organic molecules 0 Uses oxygen o Generates ATP The waste products of cellular respiration are Q oCOz and H20 Oxygen oUsed in photosynthesis Sunlight energy enters ecosystem Photosynthesis Glugose Carbon dioxide SinTa 1 Water Animals perform only cellular respiration Cellular respiration Plants perform 039 I ophotosynthesis and drlves cellular work If g 1 Heat energy exits ecosystem oCellular resp1rat1on Cellular Respiration A controlled fall of electrons The main way that chemical energy is harvested from food and converted to ATP This is an aerobic process it requires oxygen A common fuel molecule for cellular respiration is glucose errobic metabolism Occurs when enough oxygen reaches cells to support their energy needs Aerobic respiration results in 38 ATP oAnaerobic metabolism Occurs when the demand for oxygen is greater than the body s ability to deliver it Anaerobic respiration only goes through glycolysis 2 ATP Cellular respiration and breathing are closely related Cellular respiration requires a cell to exchange gases with its surroundings Breathing exchanges these gases between the blood and outside air Cellular respiration can produce up to 38 ATP STEPS 0F CELLULAR RESPIRATION The first step is an electron acceptor called NAD oThe transfer of electrons from organic fuel to NAD reduces it to NADH The rest of the path consists of an electron transport chain which oInvolves a series of redox reactions oUltimately leads to the production of large amounts of ATP All of the reactions involved in cellular respiration can be grouped into three main stages 1 Glycolysis 2 Citric Acid Cycle aka Krebs cycle 3 Electron transport Stage 1 Glycolysis 2 ATP happens in mitochondria A sixcarbon glucose molecule is split in half to form two molecules of pyruvic acid These two molecules then donate high energy electrons to NAD forming NADH Uses two ATP molecules per glucose to split the sixcarbon glucose oMakes four additional ATP directly when enzymes transfer phosphate groups from fuel molecules to ADP Thus glycolysis produces a net of two molecules of ATP per glucose molecule Glycolysis is the metabolic pathway that provides ATP during fermentation In human muscle cells lactic acid is a byproduct Stage 2 The Citric Cycle 2 ATP oExtracts the energy of sugar by breaking the acetic acid molecules all the way down to C02 oUses some of this energy to make ATP oForms NADH and FADHz Stage 3 The Electron Transport Chain 2 ATP MOST E oElectron transport releases the energy your cells need to make the most of their ATP oThe molecules of electron transport chains are built into the inner membranes of mitochondria When the hydrogen ions ow back through the membrane they release energy oThe hydrogen ions ow through ATP synthase ATP synthase Takes the energy from this ow Synthesizes ATP This is where the 02 you breathe is used POSSIBLE QUESTION Cyanide is a deadly poison that oBinds to one of the protein complexes in the electron transport chain oPrevents the passage of electrons to oxygen Fermentation The anaerobic harvest of food energy CH7 Photosynthesis Uses light energy from the sun to power a chemical process that makes organic molecules 00ccurs in chloroplasts oAlmost all plants are photosynthetic autotrophs as are some bacteria and protists They generate their own organic matter through photosynthesis Chloroplasts Are found in the cells of the mesophyll Contain stroma a thick uid Contain thylakoids membranous sacs Chloroplasts absorb light energy and convert it to chemical energy Contain Several Pigments o Chlorophyll a o Chlorophyll b J o Carotenoids Photosynthesis Equation oThe Metabolic Pathway of Cellular Respiration Is the opposite of photosynthesis reaction What s happening in Photosyntheisis Energized electrons are added to carbon dioxide to make sugar Sunlight provides the energy Photos nthesis is a twoste rocess o y p p oThe 11ght reactlons convert solar energy to chemical energy oThe Calvin cycle makes sugar from carbon dioxide Functions like a sugar factory within a chloroplast Regenerates the starting material with each turn reactions oSunlight is a type of energy called radiation or electromagnetic energy The full range of radiation is called the electromagnetic spectrum 0 Photosystem is a group of chlorophyll and other molecules that function as a lightgathering antenna Two types of photosystems cooperate in the light reactions The watersplitting photosystem The NADPHproducing photosystem An electron transport chain oConnects the two photosystems oReleases energy that the chloroplast uses to make ATP Water saving plants C3 plants oUse C02 directly from the air oAre very common and widely distributed C4 plants oClose their stomata to save water during hot and dry weather oCan still carry out photosynthesis CAM plants 00pen their stomata only at night to conserve water The Greenhouse effect Warms the atmosphere Is caused by atmospheric C02 because the C02 traps the heat in oGreenhouse gases are the most likely cause of global warming a slow but steady rise in the Earth s surface temperature CH8 Mitosis is the type of cell division responsible for oAsexual reproduction oGrowth and maintenance of multicellular organisms Asexual reproduction oSinglecelled organisms reproduce by simple cell division oThere is no fertilization of an egg by a sperm exual reproduction requires fertilization of an egg by a sperm using a special type of cell division called meiosis Thus sexually reproducing organisms use oMeiosis for reproduction oMitosis for growth and maintenance In a eukaryotic cell oMost genes are located on chromosomes in the cell nucleus 0A few genes are found in DNA in mitochondria and chloroplasts The number of chromosomes in a eukaryotic cell depends on the species Chromosomes oAre made of chromatin a combination of DNA and protein molecules oAre not visible in a cell until cell division occurs Human somatic cells have 46 chromosomes All cells except reproductive cells Two sets of 23 one from each parent In somatic cells matching pairs are called homologs 0 Each member of the pair is inherited from a different parent 0 There are 2 copies of every gene Each version of a gene is called an m Humans are Diploid organisms Diploid Their cells contain two sets of chromosomes Their gametes reproductive cells are Haploid having only one set of chromosomes Haploid Having one set of chromosomes Fertilization fusion of sperm and egg 0 Creates a zygote or fertilized egg Karyotype A method of organizing the chromosomes of a cell in relation to number size and type The chromosomes are arrested in the metaphase stage of mitosis photographed and organized Human reproductive cells sperm and egg cells have 23 chromosomes The products of meiosis Histones are proteins used to package DNA in eukaryotes Nucleosomes consist of DNA wound around histone molecules Before a cell divides it duplicates all of its chromosomes resulting in two copies called sister chromatids oSister chromatids are joined together at a narrow waist called the centromere oThe two resulting daughter cells are genetically identical because each receives a copy of every chromosome oOne chromosome can have one arm or it can have 2 sister chromatid arms oIt is still considered 1 chromosome until the chromatids separate Meiosis produces gt 4 gametes haploid Haploid gametes are produced in diploid organisms Two consecutive divisions occur meiosis I and meiosis II preceded by interphase Crossing over occurs MEIOSIS II SISTER CHROMATIDS SEPARATE TELOPHASEI W TEL P E The Cell Cycle The AND AN cvaINESIs CYTOK cell cycle consists of two distinct phases 1 Interphase Cleavage furrow ag 3 A xitx a v a n39z l t 5 Haploid chromatids daughter separate cells forming o Performs its normal functions 0 Doubles everything in its cytoplasm o Grows in size 2 Mitotic phase 0 The mitotic M phase includes two overlapping processes 0 Mitosis produce 2 daughter cells diploid I in which the nucleus and its contents divide evenly into two daughter nuclei 0 Cytokinesis in which the cytoplasm is divided in two I oOccurs during telophase I oDivides the cytoplasm I 015 different in plant and animal cells PROPHASE 39 TELOPHASE AND CYTOKINESIS Early mitotic Fragments of spindle centmsome nuclear envelope Nuclear CleaVage envelope furrow forming Chromosome consisting spindle 3 spindle Dzughtel39 E of two sister chromatids micmtubules c romosomes MEIOSIS ll SISTER CHROMATIDS SEPARATE l TELOPHASEI PROPHASE II TELOPHASE II AND Cross1ng Over CYTOKINESIS CYTOKINESIS Homologous chromosomes exchange genetic information Cleavage furrow Haplioidr Genetic recombination chromatids daughter ate cells forming occurs sepa Am Programmed cell death Two haploid cens form During another round of cell division the sister chromosomes chromatids finally separate four haploid are still daughter cells result containing single doubled chromosomes l l l I ll llllllllllllllllllllll 2 Cell Cycle Regulation Normal plant and animal cells have a cell cycle control system proteins that integrate information and send stop or quotgo aheadquot signals at key points in the cycle What Is Cancer A disease of the cell cycle oMetastasis is the spread of cancer oCancer is always a genetic disease because it always results from changes in DNA What causes Cancer oCancercausing Viruses often carry specific genes called oncogenes 0 Some Viruses have been shown to cause I A random mutation in DNA I A chemical or physical mutagen I UV radiation I Tobacco I A Virus I An inherited defective gene can predispose someone to cancer oProtooncogenes o Are normal genes that can become oncogenes o For a protooncogene to become an oncogene a mutation must occur in the cell s DNA Transformation A cell that is no longer responding to growth controls is said to be transformed Usually transformed cells are destroyed by the immune system Prophasel Duplicated pair of of meIosIs homologous chromosomes Homologous chromatids exchange corresponding segments Chiasma site of POSSIBILITY 1 POSSIBILITY 2 crossmg over 1 Metaphase Alan of Alll a meIOSIsl Spindle SIster chromatIds microtubule remain joined at their centromeres I Metaphase A MetaPhase ll W of meIOSIS ll l Gametes A A Recombinant 0 combine genetic I I information from I Recombinant chromosomes Combination a Combination b Combination c Combination d d39 erent parents39
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'