Bio 1208 Study Guide PIPETTES Mechanical Micropipettes Used for small volume transfers less than 1 mL Volume adjusted by turning adjustment rings To fill click plunger to first stop To release click plunger all the way Volumetric Transfer Designed to deliver a single volume precisely the volume will be indicated near the top of the pipette I E 5 mL Mohr Measuring Are graduated but stop at a baseline before the pipette begins to narrow Serological The tricky one To use this pipette measure all the way to the top and subtract the amount you wish to measure I E If you want to pipette 6 mL measure to the 4 If you want 4 mL measure to the 6 etc SPECTROPHOTOMETER Operating Procedure 15 min An instrument designed to detect the amount of radiant energy absorbed by the molecules 1 Turn it on Left hand knob on the front of the instrument and allow to warm up for 2 Adjust the wavelength to the appropriate value The knob on the right top of the instrument controls the wavelength which is indicated at the left of the digital display 3 With the sample holder empty and the lid closed adjust the Zero Adjust Knob Left hand Knob until the instrument reads 0 on the transmittance scale BE SURE IT IS ON TRANSMITTANCE If not push Mode Button until it is 4 Carefully insert the tube containing the blank solution into the sample holder and close the cover Use the Kimwipe Line up the white markings with the notch 5 Adjust the 100 Adjust Knob right front knob until the display reads 100 on the transmittance 6 Remove the blank and immediately insert the sample cuvette as described in step 4 above Do not change any instrument setting Switch the display to read absorbance by pushing the mode button 7 Record the Value indicated on the absorbance scale LAB 2 ANALYZING ENZYMES AND ENZYME KINETICS Many reactions require a catalyst to occur at reacts that are necessary in biology o Catalysts increases the rate of a chem react w o being consumed changed o Catalysts reduce the activation energy b w reactants and products Enzymes are highly specific Most enzymes are proteins and function depends a lot on shape Substrate is attracted to active site on the enzyme and interacts chemically with the amino acids in the active site Once it becomes the product it is no longer attracted to enzyme s active site so it leaves Reaction Catechol Oxidate Potato Extract Enzyme Benzoquinone Product LAB 3 DATA ANALYSIS o Equal to the average value and as such describes the center of the population Compare two or more populations of data Average Mean Standard Deviation Graphing o Describes how far away from the center the points spread Rate Y X n o ti a r t n e c n o C M m Time in seconds Data Interpretation o Reject Null Alternative Hypothesis Mean St Dev etc LAB 4 MOVEMENT OF MATERIALS ACROSS THE CELL MEMBRANE Isotonic On the line Same concentration so no change in mass Hypertonic Above the line More concentrated Water flows in and swells the cell Hypotonic Below the line Less concentrated so water flows out of the cell Lysis Cells placed in a hypotonic solution will rapidly swell and lyse rupture Crenate Cells placed in a hypertonic solution will rapidly shrink and crenate Permeability of the Cell Membrane o Molecules pass through lipid bilayer unless hydrophilic o OR through aqueous channels o OR by carrier mediated transport Factors determine rate of diffusion o Size polarity and charge of particular molecule LAB 5 MOVEMENT OF MATERIALS ACROSS THE CELL MEMBRANE DATA ANALYSIS AND WRITING Potato Experiment o Determine the molarity of the incubation solution where the mass of the tissue does not change indicating that the solution is isotonic to the tissue o The relative osmotic concentration of tissue will be determined by a change in mass of the tissue BUT not the actual osmotic concentration because it does not factor in turgor pressure Blood Experiment o Look at time to hemolysis o Observe the effect of molecular size and polarity on the ability of certain molecules to pass through the red blood cell membrane o Propanol took longest Then Propandiol Then Propanetriol o Null Hypothesis that the different Propanol solutions would have similar hemolysis rates and would only vary slightly due to the fact that each solution was a variation of Propanol o Alternative Hypothesis there would be differences in the hemolysis times of the three solutions and that one solution would be faster or slower than the others LAB 6 CARBON METABOLISM LIGHT AND PHOTOSYNTHETIC PIGMENTS Respiration and Photosynthesis o Cycling of carbon in the environment o In photosynthesis atmospheric carbon dioxide is fixed to produce organic biomolecules o In respiration organisms utilize carbon based molecules to produce cellular adenosine triphosphate ATP and CO2 Process of Photosynthesis o Inputs Carbon Dioxide and Water o Outputs Oxygen and Carbohydrate o Stages Calvin Cycle Light cycle reaction in light reactions light energy is absorbed by the pigments in the chloroplasts and converted to chemical energy in the form of ATP and the reduced form of NADPH o Fluorescence When a chlorophyll solution is exposed to white light the pigment molecules absorb light and become chemically excited Howerver since there are now no molecules to accept the absorbed energy it is re emitted as light energy of a longer wavelength red AKA fluorescence When extract is viewed from above light on bottom then there is still some green on top but the rest is red o Spectroscope o Chromatography A device that contains a prism and displays the total visible spectrum when a white light source is passed through the light slit If a colored transparent filter is placed between the light source and the spectroscope some of the visible rays will be eliminated from the spectrum as a result of being absorbed by the filter Separates complex mixtures into their component parts Consists of a Mobile Phase and a Stationary Phase Mobile Phase Molecules with a strong attraction for this phase move with it Stationary Phase Molecules with a strong attraction for stationary phase are inhibited from moving in the mobile phase Based on solubility The pigments move at different rates because they are not equally soluble in the solvent and because they are attracted to different degrees to the cellulose in the paper The most nonpolar pigment will travel with the solvent front The most polar pigment will stay in place move last bound to the paper Chlorophyll a blue green pigment Chlorophyll b yellow green