module 1 Flashcards
What is the scientific method
What are the variables of an experiment?
What are experimental controls?
What is sensitivity, specificity and error?
sensitivity: what is the smallest amount of change in something needed to detect that change on an instrument
What is accuracy vs precision?
What is a pH meter?
random error
What is a scale?
random error: movement/airflow can change to alter weight, scale also rounds up to nearest decimal point
systematic error: measuring outside of calibrated range may not provide accurate results
What are pipettes and micropipettes?
Pipettes:
-random error of droplets not expelled or on the outside of pipette
-systematic error of measuring from top of water each time instead of meniscus (consistent for all measurements but not correct)
micropipettes:
-systematic error of not pushing past the first position to expel last drop
-random error of air bubbles when pipetting or liquid on the outside
How can you convert between moles, concentration and volume?
what are acids, bases and pH
acids: Increases proton concentration [H+] (decrease pH)
bases: Decreases proton concentration [H+] (increase pH)
pH = -log[H+]
What are buffers
-Buffered solutions reduce pH fluctuations
What is the H-H equation and what is it used for?
If pH is less than pKa:
-there is more acid
-The acid % will be more than base %
-the acid moles will be more than base moles
How can you use H-H equation to get %acid and %base
b/a = 0.5 is the same as 0.5/1, so A = 1
what are diprotic and triprotic amino acids
-R group creates a third pKa
-pI is isoelectric point where every charge on molecule balance out
-pI = (pK1 + pK2)/2
Describe the storage of solutions
conductance increases with steam or liquid
What is autoclaving
-opening steam chamber = flash boil (explosion)
-sealing caps causes pressure build up and vessel bursts
-Sterilize bacteria
What is filtration of heat-labile compounds
heat labile: breaks down because of heat
