PHYC452Biophysics:Schedule/quiz3

Quiz 3 Topics

This quiz will cover the Beer-Lambert Law, absorbance measurements for protein and nucleic acid concentration measurements, and the laser classes for visible, CW lasers.

Students should know:

• The equation for the Beer-Lambert law
• The definition of absorbance and transmittance
• The units of molar extinction coefficient
• How to convert from a absorption cross section to molar extinction coefficient
• The wavelengths used for protein, vs nucleic acids.
• Absorbance at these wavelengths is primarly from ring structures
• The three amino acids that contribute most to protein absorbance
• The power ranges and safety considerations for visible, CW lasers for class I,II,IIa,IIIa,IIIb,IV lasers.
  • See Laser Safety and consider only the old system (not revised).

Hey does any one know the answers to thee points. I don't know where to find them online.

1. The wavelengths used for protein, vs nucleic acids.
   • 280 for protein. 260 for Nucleic Acid
2. Absorbance at these wavelengths is primarly from ring structures
3. The three amino acids that contribute most to protein absorbance

• they have the ring structure and are phenylalanine, tryptophan, and tyrosine.