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2012-02-23 10:55:59

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  1. What is cell theory?
    • All organisms are composed of one or more cells
    • The cell is the structural unit of life
    • Cells arise from pre-existing cells by division (aren't spontaneously created)
  2. What are the basic properties of cells?
    • Life
    • Highly complex and organized
    • Posses a genetic program and the means to use it
    • Capable of producing more of themselves
    • Aquire and utilize energy
    • Carry out a variety of chemical reactions
    • Engage in mechanical activities
    • Able to respond to stimuli
    • Capable of self regulation
    • Evolve over time
  3. Examples of Domain Bacteria
    • Mycoplasma: smallest known cells
    • Cyanobacteria: photosynthetic, gave rise to green plants and O2 rich atmosphere
    • Some capable of N2 fixation
  4. Examples of Domain Archaea
    • Methanogens
    • Halophiles
    • Acidophiles
    • Thermophiles
  5. 6 Model Organisms
    • E. Coli (bacterium)
    • Saccharmyces (yeast)
    • Arabidopsis (mustard plant)
    • C. elegans (nematode)
    • Drosophila (fruit fly)
    • M. musculus (mouse)
  6. Various aspects of cell replacement therapy
    • Embryonic stem cells have more potential for differentiation than adult stem cells (pluripotent). Must be differentiated in vitro.
    • Cell repl therapy: somatic cell + denucleated egg = cells that won't be rejected by host
    • Induced pluripotent cells: reprogramming of fully differentiated cel into pluripotent stem cell
  7. Limiting aspects of cell size
    • Volume of cytoplasm that can be effectively controlled by the genes in the nucleus
    • Volume of cytoplasm that can be supported by exchange of nutrients
    • Distance over which substances can efficiently diffuse
  8. Virus outside hose cell?
  9. Viral infections
    • Lytic: virus redirects host into making more particles then lyses to release viruses
    • Integration (lysogenic): virus integrates its DNA into host's chromosomes. May give rise to progeny via budding, may become cancerous, may cause lysis after triggered event
  10. Viroids?
    Pathogens that consist ONLY of a single naked RNA molecule that binds to single stranded mRNA making them unreadable by ribosomes
  11. Evidence to support endosymbiont theory
    • Absence of intermediate stage of evolution
    • Symbiotic relationships seen amongst other organisms
    • Organelles contain their own DNA, arrange prokyaryotically
    • rRNA sequencing reveals similar structure of eu organelles and pro
    • Organelles duplicate independently of nucleus
  12. What is hydrolysis?
    Water + energy = cleaving of polymers
  13. Carbohydrate formula? Two types? Enantiomers? Bonds between sugars? Various polymers?
    • (CH2O)n
    • Ketose sugars: Carbonyl (c=o) on terminal carbon
    • Aldose sugars: Carbonyl on terminal carbon
    • Enantiomers: D or L. D is found in nature.
    • Glycosidic bonds (H-O-H)
    • Glycogen, Starch, Cellulose, Chitin, Glycosaminoglycans (cell/cell communication).
  14. Amino Acid structure? Natural Amino acid? Links between AA?
    • C attached to amine, carboxyl, H, and R group
    • L stereoisomer (opposite of sugar)
    • Peptide bonds
  15. Protein levels of structure
    • Primary: sequence of amino acids
    • secondary: conformation of adjacent amino acids in a-helix or b-sheet
    • tertiary: conformation of entire polymer
    • quaternary: protein subunits interacting
    • multiprotein complex
  16. Protein misfolding diseases/description
    Creutzfeld-Jakob Disease, Mad dow, kuru, scrapie. Prion (misfolded protein) causes other proteins to fold abnormally.
  17. Describe proteomics
    • Study of the proteome (entire inventory of organism's proteins)
    • Current technology can create artificial genese to code for specific AA sequences
  18. Nucelotide parts
    • Pentose (5-cardbon) sugar [ribose or deoxyribose]
    • Phosphate group
    • Nitrogenous base
  19. Purines vs pyrimidines
    • Purines: Adenine, Guanine
    • Pyrimidines: Cytosine, Thymine, Uracil
  20. Laws of thermodynamics
    • 1) Law of conservation of energy: Energy can neither be created nor destroyed, it is tranduced between states
    • Change in internal E = heat - work (deltaE = Q - W), dE neg is exothermic, dE pos is endothermic
    • 2) Events in universe tend to proceed from higher E to lower E. Loss of available E during the process is result of tendency for entropy of universe to increase. (TdeltaS)
  21. Gibbs free energy
    • dH = dG + TdS (aka dG = dH - TdS). dG neg means rxn is spontaneous (exergonic), dG pos means rxn is endergonic
    • At equilibrium dG = 0 (no free energy)
    • Correction for standard conditions dG = dGstandard + RT lnK
  22. Cofactor vs coenzymes
    • Cofactor: inorganic enzyme conjugates (metals)
    • Coenzymes: organic enzyme conjugates (vitamins)
    • Typically located within the active site of an enzyme
  23. Mechanisms of enzyme catalysis
    • Substrate orientation
    • Changes in substrate reactivity
    • Inducing strain in substrate
    • Conformational changes
  24. Enzyme kinetics information
    • Vmax = velocity at saturation
    • Turnover # = number of substrate -> product per minute per enzyme molecule at Vmax
    • Km (Michaelis constant) = substrate concentration at half Vmax (reflects affinity of enzyme for substand. Lower Km indicates higher affinity for enzyme)
  25. Enzyme inhibitors
    • Irreversible inhibitors: bind tightly to the enzyme
    • Reversible inhibitors: bind loosely to the enzyme
    • -competitive inhibitors: compete w/ enzyme for active sites (can be overcome w/ increased substrate)
    • -noncompetitive inhibitors: bind to alternate sites, change shape of enzyme (Vmax cannot be reached, inhibition cannot be overcome)
  26. What is fermentation?
    NAHD is oxidized to NAD+ by reducing pyruvate (lactate or ethanol)
  27. NAD+ vs NADP+
    Phosphate transfered to NAD+ from ATP when cell has much excess energy. NADPH is used for forming biomolecules, NADH allows the cell to create additional ATP.
  28. Overview of membrane functions
    • Compartmentalization
    • Scaffold for biochemical activites
    • Selectively permeable barrier
    • Transporting solutes
    • Responding to external signals
    • Intercellular interaction
    • Energy transduction
  29. Main types of membrane lipids
    • Phosphoglycerides (diacylglycerides w/ small functional head groups)
    • Sphingolipids (sphingosine to fatty acids)
    • Cholesterol (smaller, less amphipathic, only animals)
  30. What is a liposome
    spontaneous lipid bilayer that occurs in aqeuous environments
  31. Membrane carbohydrates
    • Glycoproteins are for interactions with other cells/outside cell
    • Glycolipids may be cell-to-cell recognition sites
  32. Membrane proteins
    • Integral: aphipathic, anchored in in the bilayer and hydrophilic regions. Anchored to one side (eg channel proteins)
    • Peripheral: easy to removed, attached by weak bonds
    • Lipid-anchored: Glycophophatidylinsoitol (GPI)-linked found on outer leaflet, weak bonds
  33. 4 basic mechanisms by which molecules cross membranes
    • Simple diffusion: small, nonpolar
    • Open channels: (ion channels, v-gated channels) ions
    • Facilitated Diffusion: large, hydrophilic. Use of cotransport
    • Active transport (pumps): 3Na out, 2K in