Spectroscopy Flashcards
spectroscopy definition
study of interaction between radiation+ matter as function of wavelength
Examples
Infared, circular Dichroism,Raman
Colour wheel
complementary colours diametrically opposite
Wavelength max
wavelength of light absorbed most strongly
Absorbance equation
log 10 ( transmitted light/ incident light )
Beer Lambert Law
Aborbance= extinction coefficient x conc x path length
Qualitative Analysis
Finding out identity of diff compounds in samples
Quantitative Analysis
measuring conc or amount of each compound in sample ( calibration curve)
Peptide bond resonance Structure
electrons delocalized over pi bond (Shared)
Torsion (dihedral) angle
3 consecutive bonds + defined by angle created between 2 outer bonds
phi angle
N - C (alpha)
psi angle
C (alpha)- C
diff phi + psi angles =
duff secondary Structures
Ramachandran Plot
plot diff phi + psi angles + identifies secondary structures
Wavelength max effected by: x3
angle of bond, environment, H-Bonding
FTIR Used for
Bond which vibrate /twist in response to IR + absorb photons
How spectroscopy used in diagnosis
changes in metabolic pattern may produce spectroscopic markers = identification
Raman Spectrescopy Benefits
Non-destructive chemical analysis
Raman identifies / uses
identify chemical compounds/ functional groups, conformation or complex biomolecules, chemical composition /structure + in vivo measurements (during surgery)
Raman measures
degree of scatter light
Fluorescence Principle
Absorption of light at 1 wavelength + emission at longer wavelength
Intersystem crossing due to
delay of vibrational relaxation
Quantum Dot
semi - conducting single crystals used as diagnostic/ therapeutic
Using Quantum Dots for Carb changes
Bind lectin , Lectin binds carb = fluorescence or treatment
