bio 117: practical Flashcards
what are the equations for serial dilutions?
c1v1=c2v2
cs/cu=as/au
c1/c2=SDF
total V/sdf=transfer volume
how do you measure absorbances of serial dilutions?
- Labquest -> sensors -> calibrate
- after 90 second warm up, place blank, press finish calibration
- go to sensors -> data collection -> set mode to TIME BASED
- tap on red box, select wavelength, change absorbance to 550nm or wtv is given
- remove blank and place cuvette 0, press play
- record data for 10s then press stop
- go to analyze -> statistics -> record avg (mean) absorbance
- remove 0 and place cuvette 1, press play
- Repeat & discard data when asked
what is the equation for enzyme rate?
absorbance/time
what is the equation for reaction rate?
(absorbance final-absorbance initial)/(time final-time initial)
how do you calculate the pH?
- plug pH probe into channel 1 of LabQuest
- Rinse pH probe with distilled water & GENTLY wipe with kimwipe
- submerge probe in wtv is being tested, let soak for 15s before collecting data
- press play and collect for 10s
- press stop, go to analyze -> statistics -> record avg pH
how do you calculate temperature?
- plug temp prove into channel 1 of labquest
- bring probe & test buffer around room, stick in each environment
- press play and collect date for 10s
- stop, analyze, statistics, record avg temperature
how do you find the biochemical oxygen demand?
- collect 3 water samples with 3 different BOD bottles 2. plug dissolved oxygen probe into channel 1 of labquest
- rinse tip of probe with distilled water, gently wipe down with a kimwipe
- set DO probe to mg/L
- submerge the BOD bottle, hold for 40s
- press play and collect data for 10s
- stop data collection, analyze, statistics, avg DO concentration, record this as initial dissolved oxygen
- while still submerged, flip the switch on DO prove to % and measure for 10s, record avg % saturation
how do you find dissolved oxygen?
- use initial DO readings from BOD bottles for the DO value
how to find nitrate concentration?
- attach probe clamp to support stand
- CAREFULLY insert nitrate ISE to the probe clap and make sure that it is set up vertically
- uncap Nitrate High Standard and place it on the support stand, directly under the Nitrate ISE
How to find total phosphate?
- calibrate spectrovis to use for measuring absorbances
- connect the spectrovis to the labquest via USB cable
- sensors, calibrate, spectrometer- wait 90s for warm up, place blank
- sensors, data collection, change mode to “Time Based”
- Tap on the red box, select change wavelength, enter given absorbance OR 565nm
what are buffers?
an aqueous solution mixture, function to resist changes in hydrogen ion concentration.
what are protiens activity?
its activity is often dependent on pH, temp, and salt concentrations of the reaction mixture
what are stock solutions?
they are concentrated solutions that last over a long period of time
what is a dilution factor?
it is a factor by which the concentration of the dilute solution is reduced compared to the concentration of the stock solution!
what is a serial dilution?
stepwise dilution where the stock solution for each dilution is the dilute solution from the previous dilution.
