BIOL 112

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BIOL 112
2012-04-22 02:14:46

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  1. Prophase
    • • Centrosomes
    • move to the poles

    • • Spindle
    • forms

    • • Chromosome
    • condensation – chromatids become evident (remember that each chromatid is
    • actually a chromosome even though we refer to the pair of chromatids as a
    • "mitotic chromosome")

    • • Kinetochores
    • form
  2. Prometaphase
    • • Nuclear
    • envelope breakdown

    • • Polar
    • microtubules and kinetochore microtubules form

    • • Chromosomes
    • arrive on metaphase plate
  3. Metaphase
    • • Chromosomes
    • are lined up on the metaphase plate

    • • Sister
    • chromatids bound to kinetochore microtubule on opposite spindles
  4. Anaphase
    • • Centromeres
    • separate

    • • Kinetochore
    • microtubules shorten

    • • Spindle
    • elongates
  5. Telophase
    • • Spindle
    • breaks down

    • • Chromosomes
    • decondense

    • • Nucleus
    • reforms
  6. G2
    • • replication
    • of the centrosome (and centrioles in some cases).
  7. Ingredient for metaphase mitiotic spindles
    • 1) Keep the chromatids paired until it is time to segregate.
    • 2) Have unstable kinetochore microtubules that can sample the cytoplasm and only stabilize upon being captured by a kinetochore.
    • 3) Give each chromatid a kinetochore with a geometry such that two kinetochore microtubules from the same spindle can't capture both chromatids of a chromosome.
    • 4) Have a checkpoint at metaphase that senses when all the chromatids have been captured and only then allow the chromatids to separate.
  8. How does cytokinesis happen in animals
    actin and myosin, and it constricts and divides the cell
  9. How does cytokenesis happen in plants
    In plants – vesicles fuse to make cell membrane and cell plate, which eventually becomes the new cell wall.
  10. Prophase I
    • • DNA begins to compact
    • • Synapsis: pairing of homologous chromosomes
    • • Chiasmata form, crossing over.
  11. Prometaphase I
    • • Nuclear envelope breakdown
    • • Spindle fiber forms
  12. Metaphase I
    • • Microtubules attach to kinetochores (one per homolog not per chromatid)
    • • Chromosomes line up at metaphase plate held together by chiasmata.
  13. Anaphase I
    • Separation of homologous chromosomes into separate cells.Note: each cell now has two copies (two chromatids) of each homologous chromosome - these chromatids are not identical because of crossing over.
  14. Is telphase optional in meiosis?
  15. Meiosis II
    Basically just like mitosis except that you have half the number of homologs.
  16. non-disjunction event
    When the pairs of chromsome dont seperate properly and you end up with less or more
  17. Down syndrom
    When an egg with the extra chromosome joins with a normal sperm to make an embryo, the embryo will have three copies of chromosome 21.
  18. What matters, the number or chromosomes or the ration?
    Its the ratio of chromosomes that matter
  19. cis/trans(Gene Linkage)
    • If genes are linked; Dominant alleles are cis (alleles on same homologous chromosome)
    • trans (alleles on different homologous chromosomes)
  20. Types of alleles
    wild type: the predominant allele (>99% in a population)

    Mutant allele: a change from the wild type of allele, typically the result of a recent mutation. Also can refer to alleles that cause disease.

    Polymorphic: present >1% of population
  21. Epistasis
    • *complex gene interactions
    • - interation between albino (Aa) locus and (Bb) locus
    • -1st locus determines something
    • - 2nd locus determines something else
    • *often results from genes involved in different steps of the same process/pathway
  22. Genetic
    • Gene: unit of heredity
    • Allele: Different gene flavour
    • Homozygous: Having two of the same allele
    • Hemizygous: gene missing from 1 chromosome
    • Heterozygous: Having two diferent alleles
    • Genotype: the set of alleles an organism
    • phenotype: the set of traits organism display
  23. Recombination
    Linkage of alleles with crossing over
  24. How is a gene defined?
    By its location on the chromosomes
  25. Rate:
    • Measure of distance
    • -occurs at random parts of the chromosome
    • -depends on how far apart genes are on the chromosome
    • -measured of physical distance along the chromosome (Thomas Hunt Morgan)
    • * The more recombination the farther apart the genes are
  26. Linkage groups
    Are genes on the same chromosome
  27. Polygenetic or multigetic traits
    • Multiple genes contribute to a trait
    • ex: heart attack risk
    • -6 genes affect
    • -If each gene has a semidominatn alleles, 12 genetic risk level
  28. Enviromental contributions to phenotype
    Penetrance: % of individuals of a given genotype that show the phenotype at all

    Expressitivity: The degree to which a phenotype is expressed (ex. shades at pink in a flower)
  29. Fermentation
    • -Absence of O2
    • -Generates NAD+ glycolysis going
    • -lactic acid by product (or alcohol)
    • -never occurs in brain cells

    • Note: Gluconeogenesis: process by which intermediates of glycolysis/ citnic acid cylce ae used to form glucose.
    • -Intermediates can also--> COH fatty acids
    • ---> amino acids/ purines- pyrimidines
  30. Electron Transport Chain
    • 1.NADH oxidized e-given to NADH-Q reductase - proton pumped
    • 2.FADH oxided e- given to succinate dydrogenase - proton not pumped
    • 3. e- go to ubiquinone--> cytochrome C reductase
    • 4. e- go to cytochrome C---> cytochrome C oxidase - proton pumped -O2 e- acceptor- H2o +2H+

    • Purpose: set up "electochemical gradient"
    • *oxidation of enzymes--> conformation change-->trans H+
  31. Pigments
    • *Chlorophyll a- action center
    • *Chlorophyll b (max absorption blue 420nm/red 680nm
    • *ring attached to tail (inside thylakoid membrane)

    • Absorption spectrum- where pigment absorbs most light
    • Action spectrum- corresponds roughly to combined spectra of chlorophyll/ cartenoid
  32. Pyruvate oxidation
    • 1. Pyruvate oxidized to a 2C acetyl group and CO2 released
    • 2. Reduction of NAD+---> NADH+H+
    • 3. CoA is attached
    • look at diagram
  33. Glycolysis
    • In cytoplasm**
    • 1. ATP invested, phosphate added
    • 2. isomerization, ATP invested, phosphaleadded
    • 3. Symmetry- split into 2 C3 atoms (63p)
    • 4. 2x-63P oxidized 2 molecules NADH+H+ formed
    • 5. P group transferred to ADP--> ATP (2x)
    • 6. Isomenzation, loss of H2O (2x)
    • 7. Transfer other phosphate to ADP--> ATP (2x) **substrate level phosphorylation
    • 2ATP invested---4ATP made 2Pi invested
    • 2(NADH+H+) 2(H2O) evolved * last step has LARGE delta G
  34. Redox Reaction
    • Reduction: gain of electron
    • Oxidation: loss of electron

    • Oxidation of organic molecules decreased the number of C-H bonds
    • Tendency to gai/lose electrons is called redox potential

    ex. NAD+ 2H--- +H+ (2H+ +2e-)
  35. Calvin Cycle
    • 1. 6O2 combines with acceptor RUBp forming 6(3PG) (rubisco)
    • 2. 6(36P) is reduced to 63P is 2 step rxn requiring 12ATP and 12 NADDH+12+
    • 3. About 1/6 63P (2) used to make sugars- output
    • 4. Remaining 63P (1) precessed to make RUMP
    • 5. RUMP--RuBp with the use of ATP

    3Stages: carbon fixation (1). Reduction and sugar production (2)(3)Regenration RuBp (4)(5)

    *photorespiration: O2 instead od CO2--releases CO2 reduces net c fixed
  36. Regulation
    • -Glycolosis
    • Kinase: inhibits by high ATP
    • -Citnic Acid Ccle: 1st dehydrogenase: high NAD+ activates high NADH+H+ inhibits

    • ETC:
    • -regulated by H+ gradient
  37. Citric Acid Cycle
    • *In Mitochondria*
    • 1. 2C acetlyl and 4C oxaloacetate combine-- 6C
    • 2. Iso citrate oxidized, CO2 released NAD+ reduced
    • 3. alpha-ketoglurate oxidized, NAD+ reduced, CO2 released
    • 5. Succinul-CoA--succinate GTP-GDP, ATP--ADP
    • 6. Reduction of FAD---FADH2--fumarate
    • water added--malate
    • 7.Malate--oxaloacetate, NADH+H+ formed

    • 2[3NADH+H+FADH2+ATP]
    • **Fermentation oxidized NADH+H+---NAD+
  38. Light Cycle
    • Noncyclic: (H2O replenisheds e-)
    • 1. Photon strikes PSII (680)e captured by primary acceptor--plastoquinone (pumps H+ in)--cytochrome complex--plastocyanin
    • 2. Photon strikes PSI and re-energizes e- (700) raptured by Ferredoxin---NADP reductase (NADP+ +2H+---NADPH+H+)
    • Cyclic:
    • 1.Photosystem I energyzed--Fd--ETC--Photosystem I (pumps H+ in therefroe ATP synthesis)
    • **Followed by Chemiosmosis
  39. Chemiosmosis
    • Potential energy of the H+ gradient a proton motive force
    • -harnessed by ATP synthase
    • *Funit Founit--rotates
    • -channel allowing H+ to diffuse back to the matrix
    • make ADP into ATP
    • *oxidative phosphoralation
    • ATP synthase can work in reverse
    • -imstead of using synthase, other enzyme produces
  40. Cell Theory
    • All organisms consist of cells
    • Cells divide to provide new cells
    • Higher organisms fuse their cells(sperm and eggs, pollen and egg) to produce a new organism
    • *all organism come from a single cell which cleave and multiply to give rise to multicelluar organim*
  41. Cell Adhesion
    basal(amina=thin mat extracellular matrix
    apical faces lumen
    baslateral: away from lumen
    • 1.Tight Junction:
    • seperates apical and basolateral membrane domains
    • prevent substances from moving through the intercellular space (prevent leakage)
    • 2. Adherens junction:most important/ancient
    • circumferential belt close to apical basolateral boundary
    • made of cadherins (stick out and bind to other cadherins on ther cells)
    • then connects to actin filaments
    • set up initial polarity
    • lnk actin bundle in one cell to actin bundle in other
    • 3.Desmosomes: provide mechanical stregth (skin);connected to intermidate filaments (in both cells)
    • 4.Gap Junction- channels (connexins)
    • facilitate communication between cells-(heart cells)(cat ion move)
    • 5.Focal Adhesion- anchors action filaments in a cell to basal lamina
    • made of transmembrane intergrins
    • connect to actin filaments
  42. Cytoskeleton
    • Cilia-locomotony appendages of cell (made of microtubules)
    • -shape/polarity
    • mechanism of cell movement
    • acts as tracks for motor proteins
    • ACTIN FILAMENTS(+ve..........-ve)
    • add structure to plasma membrane/shape cell
    • with myosin:cell shape changes, cell migration and muscle contraction
    • INTERMED FILAMENT:rope like assemblages in cell (multi)
    • stabolize nucleus (lamins)/mechanical strength
    • MICROTUBULES:hollow tubules (tubulin) cell polarity, tracks (kinesin/dyein)--extend from centriol
  43. Sodium Potassium Pump in membrane transport
    • 3Na+1ATP(out)
    • S.C--2K +(in)
    • S.C--repeat
  44. Membrane transport
    • 1Diffusion--Brownian movement
    • rate:distance, temp, size of molecule and concentration of gradient(Gases/water can cross, large polar molecules and small ions CANNOT PASS
    • 2. Facililitaed Difusion:
    • Channel:opens/closes/w/ stimulus molecule
    • carnier:binds transported substance carrier proteins get saturatt, channel proteins do not.
    • 3.Active Transport:
    • Primary:uses ATP directly-sodium Potassium Pump-to control osmolarity and generate of membrane potential NA+k+ATase-animals!
    • Secondary:uses established gradient to move substances(follows primary) then use symport + antiport to move substances
    • symport(2substance. 1direction)
    • antiport (2substances 2 directions)
    • uniport(1substance 1direction)
  45. Golgy
    • small membranous sacs (pancakes)
    • small membrane enclosed vesicles
    • receive proteins from ER and further modify add olisosacchandes to membrane lipids
    • concentrate package and sort of proteins before they are sent to destinations (exocytosis and endocytosis)
    • phagasocytosis (pinching of cell membrane)
    • lysosomes made by golgi
    • autophagy- self eating
  46. Prokaryotes
    • small, no nucleus, no membrane-bound organelles--bacteria
    • inhibits widest range of enviromental extremes b/c great metabolic diversity
    • can use light rxns, H2,S,Fe,N...etc(methane, benzene,fluorocarbons)
    • ribosomes smaller
    • DNA is usually single stranded circular chromosomes located in nucleoid
  47. Endosymbiotic Organelles
    • symbionds-organism that lives in harmony withing another organism
    • Mitochondria
    • outer plasma membrane, inner folded membrane (cristae)
    • cellular respiration (Kreb's Cycle and ETC)

    • Chloroplasts(plastid)
    • photosysthesis
    • outer membreane and inner membrane (thylakoids--granum, lumen, stroma)
    • photosynthesis ocurs in stacks
    • carbon fixation in stroma
  48. Endoplasmic Reticulum
    • ER-Network of interconnecting membreanes
    • (lument different ion/protein comp communicates only w/ outside of cell)
    • membrane can be cont. w/ outer nuclear envelope
    • makes phospholipids
    • insert membrane proteins
    • RER-ribosiome directed after transcription of first few amino acids
    • Oligosacchanides: (3-12 glucose) attached to protein
    • Enzyme in ER detoxify many substances
  49. Eukaryotes
    • Compartmentalization!
    • each organelle has its role
    • Endomembran system
    • -ER
    • -Golgy
    • -Cell membrane
    • -nuclear membrane
    • -vescicles
    • Nucleus!
    • -DNA replicared
    • - lipid bilayer(nuclear pores)
    • -transcription mRNA, rRNA
    • -rRNA folds (4 rRNA +80proteins form ribosomes in nucleolus) ribosomes 2parts:activate outside
  50. Energy and Rxn
    • 1st law-emergy is not created nor destroyed
    • 2nd law- entropy increase is favourable

    • RXNs
    • 1.Heat released, disorder increased:always spontaneous (exergonic)
    • 2.Heat released, disorder decreases spont. at low temps
    • 3.Heat used, disorder increases: spont. at high temps
    • 4. Heat used, disorder decreased; never spontaneous(endergonic)
    • delta G=0 at equilibrium
    • a ⇔B is always reversible
  51. Enzymes
    • Only rxs with overall - delta G can be catalysed . delta G does not change!!
    • lower Ea
    • enzymes:
    • orient substances
    • strain inducing in substrates
    • add charges to substrates
    • saturate when all binding sites occupied
    • cofactors-anything but amino acids
    • regulation-inhibited by natural/artificial binders
  52. Inhibition
    • a) competative
    • competes with substrate for binding site
    • b) non-competitive (+ve/-ve allosteric reg)
    • binds to site distinc of active site
    • -ve:conformation change to stop substrate
    • +ve: conformation change to allow substrate
    • (c)Coorperative: two or more subunits(makes 2nd inhibitor easier to bind)
  53. Cells
    • small b/c require diffusion which requires "bronian motion"
    • distance traveled alpha srt(time)
    • size limited by high SA/volume ratio (only this allows diffusion to make place fast enough)
    • -eggs can be larger b/c no diffusion takes place, simply storage containers
  54. Macromolecules
    • Can form polymers
    • present in all organisms in smae porportion
  55. Condensation
    Anabolic- produces H2O
  56. Hydolysis
    Catabolic-requires H2O
  57. Structural Isomers
    chiral mirror image (occurs with a carbon attached to 4 diff functional groups)
  58. Lipids (Vi+ A and D)
    • Hydrophobic
    • engergy storage
    • cell membranes
    • electrical insulation of nerves (Brain)
    • water repellency (waxes/oils)
    • Triglyceride(esterlinkage)(3H2O)
    • unsaturated-double bonds(kinks)
    • saturated-no double bonds
    • phospholipids; (phophatidylcholine)
    • (2fatty acids-glycerol-phosphate-choline)
  59. Buffers
    Make solution resistant to pH change, b/c reacts with both added bases and acids

    The law of mass action: Add reactants speed reaction as well decrease product increase reaction
  60. Functional Groups
    • alcohol
    • ketone
    • carboxyic acids
    • aldehydes
    • amines
    • thiols
    • orgranic phosphates
  61. Membranes
    • Phospholipids bilayer:
    • cholesterol-makes it rigid
    • unsatureated fatty acids-fluis
    • leaflet is one layer
    • mvmt:lateral mvmt (diffusion),flexion, rotation, flip flop (occurs to gernerate a-symmetry)
    • -ouside-sugars
    • inside-charged lipids (cytosolic)
    • The fluid mosaic model:mosaic of proteins in 2D fluids
  62. Membrane Protein
    • Transmembrane Proteins:
    • hydrophobic region faces inside
    • Hydrophilic: faces outside

    • Peripheral membrane proteins:
    • lack hydrophilic groups
    • covalentrly bond to lipids or non covalently bond to transmembrane protein
    • Function: signal transduction, transport of molecules energy generation, cell adhesion
  63. Acid
    Releases H+ ions in solution
  64. Bases
    accepts H+ ions in solution (releases OH-)
  65. Starch
    • Polysaccharide alpha (1-->4) link
    • long chain is bent curve and eventually spiral
  66. Examples of starch
    • Amylose- Unbranched
    • Amylopectin- moderately branched (plants
    • )Glycogen -highly branched (animals)
  67. Cellulose
    • Beta (1-->4) link
    • Always unbranched
    • every other B glucose is flipped
    • alwats linear
  68. Is starch branched
    • Amylase its unbranched
    • Amylopectin its moderately branched
    • Glycogen its highly branched
  69. DNA
    • genes
    • protein manufactur
    • signalling/energy transducers
    • phosphate binds to C5
    • pentose sugar w/o is deoxy (DNA)
  70. Purines?
    • Double ring
    • Adenine
    • Guanine
  71. Pirimidines?
    • single ring
    • Cytosine
    • Thymine
    • Uracil
  72. Carbohydrates
    • energy storage
    • building blocks for other molecules
    • structuaral compenent
    • provide cell identity by embedding into cell membrane
    • joined by glycosidic linkages
    • Glucose:forms ring in water stable
  73. DNA and RNA