Post-Lab Exam Discussion.pdf

Post-Lab Exam Discussion Exercise 1 Microscopy and Micrometry Microscopy - the technical field of using microscopes to view samples & objects that cannot be seen with the unaided eye Micrometry - technique used to measure microscopic objects. It involves calibrating an ocular mic...

Post-Lab Exam Discussion Exercise 1 Microscopy and Micrometry Microscopy - the technical field of using microscopes to view samples & objects that cannot be seen with the unaided eye Micrometry - technique used to measure microscopic objects. It involves calibrating an ocular micrometer using a stage micrometer Different parts of microscope/function compound light microscope - since the source of visibility is light/ compound - more than one lens 1. ocular lens/eyepiece - def: where specimen is viewed/ func: magnify specimen 2. body tube - func: holds eyepiece lens/desc: connects eyepiece to revolving nosepiece 3. revolving nosepiece - holds different objective lenses 4. objectives lenses - same funcs: magnify specimen 5. arm - arch connecting to body tube and stage/ func: hold the microscope 6. stage - func: holds the specimen 7. stage clips - func: holds the specimen in place 8. light source - always found in the bottom of the microscope/ LIGHT not MIRROR 9. condenser - func: regulates the amount of light 10. base - bottom most part/ supports the whole microscope 11. main adjustment knob - rough focusing 12. fine adjustment knob - fine focusing Viewing image is inverted with respect to original position why inverted: (1) convex lenses (2) two convex lenses whenever light from the specimen passes through objective lenses, it will not be inverted. but if it passes to the second lens (ocular lens), it becomes inverted. Calibrating the microscope calibration constant (μm, micrometer) - (stage micrometer spaces/ocular micrometer spaces) × 100 ocular micrometer - always ginagamit pang-measure more reliable yung built in na ocular lens stage micrometer is bigger than ocular micrometer stage is 1mm long ○ per 1mm = 100 division ○ 1 division= 0.01 mm or 10 um (micrometer - 3 decimal places to the right) ○ ocular = 0.1 mm calibration - purpose: quantitatively specify measurement of each division/space in the ocular micrometer scale length/width (cm) - number of spaces covered in the ocular micrometer × calibration constant Linear magnification = ocular lens magnification x objective lens magnification magnification = size of the drawing (mm) /width (mm) review conversion !! Field of View - diameter of the FOV decreases as magnification increases ○ Largest at LPO HPO: views one plane at a time Oil Immersion Lens: focuses three threads at a time Exercise 2 Plant and Animal Cell focus review on lecture function of organelles mitochondria - packing/sorting of the cell cytoplasm - an area between nucleus and cell membrane cytosol - water part protoplasm - living material (whole cell w/o cell wall) No vacuoles in plant cell - vesicle in animal cell Exercise 3 Cellular Transport structure of plasma membrane ○ water and oil - oil globules represent an intact amoeba ○ amphipathic: hydrophilic head, hydrophobic inner (tail) ○ amoeba - a common freshwater organism if staining molecule has opposite charge, molecule will not enter saline solution - to lyse the cell; for the methylene blue to penetrate the cell Lyse - breakdown of the outer membrane of the cell Selective Action of the Plasma Membrane natural red dye Congo red ○ weak cationic dye ○ neutral red molecules will easily bind to the anionic sites of lysosomes Active Dry Yeast - Saccharomyces cerevisiae Mas acidic sa loob due to proton pumps internal (acidic) = deep red external (basic) = yellowish orange environment is basic pump out, the environment becomes alkaline Two Major Conditions of Selectivity 1. 40% Formalin - cross linking of proteins, halted all living processes and blocked protein channels 2. Heat - denatures proteins Denaturation - breakdown of proteins Diffusion - solute lang gumagalaw; net movement from higher concentration to lower concentration collodion tube/film - smaller particle size, faster rate of diffusion two major factors ○ Size; inversely proportional; increased surface area increases the rate of diffusion, whereas a thicker membrane reduces it. ○ Polarity; hydrophobic region repels polar molecules–thus a need for polar protein channels to diffuse through the membrane Permeability of Plasma Membrane - structure of the membrane Osmosis boat of moses - Tradescantia spathacea distilled water - hypotonic/turgid solute concentration of boat moses - 0.5 0.5% NaCl - isotonic/flaccid 1.0% NaCl - hypertonic/plasmolyzed Hemolysis rbc - Erythrocytes distilled water - hypotonic/lysed 0.9% NaCl - isotonic/normal solute concentration of rbc = 0.9 10% NaCl - hypertonic/shrivel Exercise 4 Photosynthesis variegation in plants ○ “veined variegation” mutations in the plastid genome ○ non-green areas: lack of chloroplasts boiling - removes cuticle, denatures protein 95% Ethanol (C₂H₆O) - extraction of the chlorophyll polarity “like dissolves like” (amphiphilic kasi ang alcohol) ○ Amphiphilic - hydrophobic and hydrophilic Leaf with Iodine iodine particularly binds to amylopectin-iodine green: positive for starch non-green: negative for starch Light as a Factor in Photosynthesis 48-72 proper destarching time 36 hours Covered Leaf - aluminum foil/may be positive or negative Uncovered Leaf - strongly positive for iodine starch Hydrilla verticillata phenol red - pH indicator Blowing of c02 → makes the solution acidic → to make c02 readily available  c02 + h20 → h2co3 (carbonic acid) through opening of stomata, leaf would absorb carbon dioxide -> color change happens Exercise 5 Cellular Respiration positive in glucose, sucrose, brown sugar negative in fructose, lactose Effect of Exercise more c02 - more strenuous activity excess co2 - breathing rate and volume increases, bp increases, heart rate increases c02 - a byproduct of cell metabolism and is carried by the blood through venous system Exercise 6 Cell Cycle prophase - grainy appearance - condensation of chromosomes metaphase - alignment of chromosomes along metaphase plate anaphase - separation of sister chromatids - wag separation of chromosomes (meiosis yon) telophase - separation of the cell / nucleus - animal - cleavage furrow - plant - cell plate Meiosis (frog testis) spermatozoon/differentiated sperm - hairy structure spermatids/t2 secondary spermatocyte/p2 - darker primary spermatocyte/p1 - lighter  Seminiferous tubules - yung buong bilog