amine and amino acids Flashcards
What are the uses of amines?
amphetamine - stimulant
putrescine - found in decaying meat
Why are amines basic and nucleophilic?
amines are basic and nucleophilic because they have a lone pair
- can donate a pair of electrons
- are attracted to positive charge
Why is aniline a weaker base than aliphatic amines?
reluctantly accepts the proton
readily reverses back to become deprotonated
- loses resonance stabilisation upon protonation = makes it less stable and more reactive
shown by resonance stabilisation lone pair in the p orbital is in conjugation with the benzene ring
- electron withdrawal of the adjacent benzene ring makes the lone pair less readily available to act as a base = donate pair of electrons
Why type of reaction can amines go under?
substitution reaction = Sn2
- acts as a nucleophile and base
What are alkaloids?
nitrogen containing compounds of low molecular weight
- produce physiological responses
What are the uses of alkaloids?
pain relief
- opioids = narcotics that act on opiod receptors, contain morphine which is then processed chemically into heroin
kill animals
- coniine = poison found in hemlock, causes paralysis and asphyxia
atropine
- treats damage caused by nerve agents
How do epoxides react with bases and weak nucleophiles?
epoxides react with bases and weak nucleophiles at the least hindered carbon
- carbon atom with the smallest number of attached constituents
How do epoxides react under basic conditions? What are the requirements for the reaction?
epoxides react at the least hindered carbon and form alcohols
requirements
- NaOH
- water
- reflux
Which amino acids’ alpha carbon is not chiral?
Which amino acid does not have a S configuration?
all amino acids have a chiral alpha carbon except for glycine
- the R group is a H atom
all amino acids have an S configuration except for cysteine
- cysteine has an R configuration
What do the dash and dotted lines mean in structures?
dashed line
- towards you
- should have the highest priority group = highest molecular weight
dotted line
- away from you
- should have the lowest priority group = lowest molecular weight
In what form do the amino acids exist in?
amino acids exist as zwiterrion
- they are not acidic or basic
- they can never exist an uncharged compound
What is the isoelectric point?
pI = pH
- the isoelectric point is the point at which there is no charge = zwitterion
- positive charge is equal to the negative charge
What is Strecker synthesis?
synthesis of amino acids from an aldehyde
- using ammonium chloride and sodium cyanide
What are the requirements for Strecker synthesis?
ammonium chloride and sodium cyanide = generate reactants
- ammonia
- hydrogen cyanide
concentrated acid and water is needed for the final step to convert the nitrile group into carboxylic acid
- hydrolysis of nitrile
What are peptide bonds? How are they formed and written?
peptide bonds
- amide bonds that link amino acids
- formed by condensation reaction between amino acids = water loss
peptides are written with peptide bonds. they position the amine group to the left and the carboxylic acid group to the right
