purification and analysis quick flashcards

what are primary metabolites

have metabolic functions essential for plant growth & development

carbs, lipids, amino acids, vitamins

compare primary and secondary metabolites

secondary metabolites don’t have apparent functions in growth and development

secondary metabolites aren’t produced in every plant

include terpenoids, special nitrogen metabolite non proteinogenic amino acids, amines, cyanogenic glycosides, glucosinolates and alkaloids and phenolics

what are some methods used in phytochemistey

TLC

gel chromatography

gas chromatography

mass spectrometry

nuclear magnetic resonance

x-ray crystallography

what is extraction based on

based on the different solubility of different molecules in organic solvents or aqeuous phases

explain the solubility of table salt in water

sodium cations and chloride anions become surrounded by water brining the salt in solution

what is the stationary phase

a solid or liquid that is fixed and interacts with the sample in TLC

eg silica gel and alumina

what is the mobile phase

a liquid or gas that carries the sample mixture through the system in TLC

what is the retention factor

distance traveled by sample/ distance traveled by solvent

what is the principle of TLC

compounds have different affinities for the mobile and stationary phases

this affects the speed at which it migrates

what does the speed of the compound travelling depend on

compound is soluble in solvent = travel further up TLC plate

if compound likes stationary phase = not move very far up TLC plate

what can we used for compounds which are not UV active in TLC

chemical stains

how do we purify compoudsn

using column chromatography we separate a chemical by passing it through a column filled with solid stationary phase and liquid mobile pahse

components of the sample based on their polarity and interactions with stationary phase travel through column at different rates and separate

how does mass spectrometry work

step 1: produciton of gas phase ions of compound, basically by electron ionization, molecular ion undergoes fragmentations

step 2-3: ions separated according to mass-to-charge ratio, are detected in proportion to their abundance

step 4: mass spectrum of the molecule is produced

example of mass spectrum

how is crystallography used

can get the structure

based on the analysis of the diffraction patterns that emerge from a sample targeted by a beam like an X-ray

how does crystallography work

X-rya beams shot through crystal of a molecule

crystal causes beam to diffract in a predictable pattern based on their crystal lattice structure

results in diffraction pattern

diffraction caused by electron clouds: higher atomic number = large electron clouds

what can X-ray crystallography be used for

stereochemistry

bond length

distance between atoms

CAN’T REVEAL WHAT ELEMENTS ARE PRESENT

what is infrared spectroscopy

based on absorption measurement of different IR frequenciess

used to detect presence of specific functional groups and other structure features from band poisitions and intensities

what is nuclear magnetic resonance

based on properties of certain nuclei when they’re in a strong magnetic field

information we get is related to atoms, their neighbouring atoms and interaction of atoms far away in a linear chain but brough close together if molecule is flexible

how does NMR work

when nucleus possess a magnetic moment (eg 1H or 13C) and is placed in a strong magnetic field, it spins

what information can we get from NRM

composition of atomic groups in the molecule

info about adjacent atoms

info on molecular dynamics

quantitative info eg atomic rations in a molecule