BSCI330 Exam 1 Review Cell Theory All living organisms are composed of nucleated cells except bacteria All cells come from pre existing cells o Except synthetic cells now come from placing a genome in a preexisting cell Cells are functional units of life Universal features of cells All cells contain a nucleus except bacteria All cells contain a plasma membrane All cells have the same gene expression of translating RNA into protein All cells use proteins as catalysts All cells can store their hereditary information as linear DNA code All cells use the transcribe hereditary information into the intermediate form All cells replicate hereditary info by using templated polymerization DNA RNA Model Organism Site directed and tissue specific mutagenesis is possible Genome has been sequenced Expression of multiple can be tracked across many cells simultaneously The developmental sequence is known Nucleotide Monomer composed of two parts o A base either guanine adenine thymine cytosine o A sugar deoxyribose with a phosphate group attached Make up DNA strand sugar phosphate linkages Within each DNA strand the bonds are strong covalent Between the complementary strands the bonds are weak Hydrogen bonds Templated Polymerization Sequence of nucleotides in existing DNA strand control for the sequence of the new DNA strand A T C G Process of DNA Protein 1 DNA synthesis replication 1 2 RNA synthesis transcription 3 Protein synthesis translation o Segments of DNA sequence are used to guide the synthesis of RNA o RNA molecules are used to guide the synthesis of molecules of protein Genes New genes arise from existing genes by Intragenic mutation o An existing gene can be modified by changed in its DNA sequence Gene duplication o An existing gene can duplicate in the genome Vertical Gene Transfer Passing down genes from parent to offspring Handing down of genes to daughter cells during cell division asexual and sexual reproduction Meiosis and Mitosis included Horizontal Gene Transfer Passing genes to another cell that is not its offspring Transfer of genes between existing organisms or cells both in nature and in the lab Prokaryote Prokaryote Prokaryote Eukaryote and vice versa o Via viral vectors DNA protein coat or plasmids DNA alone Eukaryote Eukaryote very rare Homologous Genes related by descent and have recognizably similar properties Orthologs o Genes that have resulted by a gene diverged following speciation o Predicted to have the same function Paralogs o Genes that have resulted by a gene duplicated within a species o Predicted to have different but related functions Life s Domains tree of life 1 Archea 2 Bacteria o 1 and 2 are Prokaryotes No nucleus or membrane bound organelles Have DNA Have 1000 6000 genes Ribosomes make protein inside cytosol Cell wall is permeable but not plasma membrane o 3 Eukaryotes 2 o Protists fungi plants animals Mitochondria Membrane bound organelle in most eukaryotic cells Generate ATP for energy Origin o An ancestral eukaryotic cell is thought to have engulfed the bacterial ancestor of mitochondria initiating a symbiotic relationship o This makes eukaryotes have a hybrid genome o Used to make specific and intentional changes to the DNA sequence of a gene Mutagenesis Site directed mutagenesis and any gene products Tissue specific Energy Energy used to do work o Mechanical movement of cells molecules o Electrical separation of positive and negative charges o Formation breaking of chemical bonds o Heat production o Light production Storage o Chemical bonds ATP glucose NADPH o Electrical potential differences o Chemical concentration gradients when cells move across membranes they do so to store energy in the form of concentration gradients Acceleration and Velocity In a vacuum putting force on particle results in constant acceleration In a viscous fluid there is drag so putting force on a particle results in constant terminal velocity First Law of Thermodynamics Conservation of energy Enthalpy heat content H o H Breaking bonds energy is required heat is released If energy required energy released H o H Forming bonds energy is released heat is gained If energy required energy released H 3 o H H products Hreactants H2O ATP ADP Pi o When breaking down ATP you make new products which contain more stable bonds energy is released Second Law of Thermodynamics Allows cells to convert the release of bond energy into increased biochemical order Free Energy G Sources of free energy o Light free energy Phototrophic o Organic Chemicals Organotrophic o Inorganic Chemicals Lithiotrophic Anaerobic do not require oxygen Aerobic combine inorganic chemicals with oxygen G H T S o S entropy change disorder S more disorder S less disorder more order G free energy G maximum energy available to do work o Reaction moves right spontaneous free energy is released G minimum energy available to do work and for the reaction to proceed Reaction moves left non spontaneous free energy is required G RTln B A G G 0 equilibrium No net flux materials 0 o If G 0 is large and negative it is likely that the reaction will proceed in the direction A B spontaneously to the right prod react 1 G 0 RTln prod react o Coupling of Catabolic and Anabolic Reactions Metabolism Catabolic Anabolic Steady States o Disassembly of complex molecules to simpler ones o Many catabolic pathways release energy which can be stored o Synthesis of more complex molecules o Most anabolic pathways require an input of energy from coupled reactions o Reactions not at equilibrium o Requires energy to maintain o Concentrations of reactants are constant but there is a steady net flux of material through the coupled reactions reactants not changing with time Coupled reaction an energetically favorable reaction drives an energetically unfavorable one that produces an energy store 4 Products continuously removed and reactants continuously added Coupled reaction o Use of an activated carrier molecule ATP and activated intermediate phosphorylated X Making the polymer X X from 2 molecules of X First phosphorylate X using ATP to form an activated phosphylated intermediate o 2ATP 2X 2X P 2ADP Then combine two of the phosphorylated X s o 2X P X X 2Pi These reactions are equivalent to o 2ATP 2ADP 2Pi Go 11 3 x 2 22 6 kcal o 2X X X Go 3 kcal Overall Go 22 6 3 kcal 19 6 kcal per mole X X formed Activation Energy EA o Minimum energy required for a reaction to occur o May be provided by unusually energetic collisions with other molecules o
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