BSCI330 Exam 1 Review Cell Theory- All living organisms are composed of nucleated cells (except bacteria)- All cells come from pre-existing cellso Except synthetic cells now come from placing a genome in a preexisting cell- Cells are functional units of lifeUniversal 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 DNARNA- All cells replicate hereditary info by using templated polymerization“Model Organism” Genome has been sequenced Site-directed and tissue-specific mutagenesis is possible Expression of multiple can be tracked across many cells simultaneously The developmental sequence is knownNucleotide- 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)o Segments of DNA sequence are used to guide the synthesis of RNA- 3. Protein synthesis (translation)o RNA molecules are used to guide the synthesis of molecules of proteinGenes- 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 genomeVertical 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 includedHorizontal 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- ProkaryoteProkaryote- ProkaryoteEukaryote (and vice versa)o Via viral vectors (DNA + protein coat) or plasmids (DNA alone)- EukaryoteEukaryote (very rare)Homologous- Genes related by descent and have recognizably similar properties- Orthologso Genes that have resulted by a gene diverged following speciationo Predicted to have the same function- Paralogso Genes that have resulted by a gene duplicated within a specieso Predicted to have different, but related functionsLife’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 membraneo- 3. Eukaryotes2o Protists, fungi, plants, animalsMitochondria- 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 relationshipo This makes eukaryotes have a “hybrid” genomeMutagenesis- Site-directed mutagenesiso Used to make specific and intentional changes to the DNA sequence of a gene and any gene products- Tissue-specificEnergy- Energy used to do work:o Mechanical (movement of cells, molecules)o Electrical (separation of positive and negative charges)o Formation/breaking of chemical bondso Heat productiono Light production- Storage:o Chemical bonds (ATP, glucose, NADPH)o Electrical potential differenceso 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 velocityFirst Law of Thermodynamics- Conservation of energy- Enthalpy (heat content) HΔo – H Δ Breaking bonds, energy is required, heat is released If energy required < energy released = - H Δo + H Δ Forming bonds, energy is released, heat is gained If energy required > energy released = + H Δ3o H = HΔproducts – 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 orderFree Energy GΔ - Sources of free energy…o Light (free) energy - Phototrophico Organic Chemicals- Organotrophico Inorganic Chemicals- Lithiotrophic Anaerobic (do not require oxygen) Aerobic (combine inorganic chemicals with oxygen)- G= H –T SΔ Δ Δo S= entropy change (disorder)Δ + S= more disorderΔ - S= less disorder (more order)Δo G= free energyΔ - G= maximum energy available to do workΔ- Reaction moves right, spontaneous, free energy is released + G= minimum energy available to do work and for the reaction to Δproceed- Reaction moves left, non-spontaneous, free energy is required G= 0 Δ equilibrium (No net flux materials)- G= RTln([B]/[A]) + GΔ Δ0’o If GΔ0’ is large and negative, it is likely that the reaction will proceed in the direction AB (spontaneously to the right) prod/react > 1o GΔ0’= -RTln(prod/react)Coupling of Catabolic and Anabolic Reactions- Metabolism- Catabolico Disassembly of complex molecules to simpler oneso Many catabolic pathways release energy, which can be stored- Anabolico Synthesis of more complex moleculeso Most anabolic pathways require an input of energy from coupled reactions- “Steady States” o Reactions not at equilibriumo Requires energy to maintaino 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 store4- 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
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