Polymers and Life - Amines and Amino Acids Flashcards
what is the structure of a primary amine?
what is the structure of a secondary amine?
what is the structure of a tertiary amine?
what is the functional group for amines?
at least one C-N bond, other bonds on the N are either to a H or other alkyl groups
what is the solubility of amines in water?
small amines are soluble in water, large amines are not
why are small amines soluble in water and large amines insoluble?
there is a lone pair on an electronegative atom with 2H also attached to it
the lone pair and H atoms can hydrogen bond with water
in small amines, the bonds are sufficient to solvate the molecule
in large amines, molecules would have to break many H bonds already present while only forming 3 H bonds so cannot solvate
what is the functional group of amides?
how are primary amines named?
either amino as a prefix - used with <1 group
or amine as a suffix - used with 1 group
are amines acidic or basic?
basic
how are amides formed?
when an amine and carboxylic acid react
why don’t amines and amides act similarly?
because the carbonyl group on an amide makes it act more like an ester than an amine
what is the structure of a primary amide?
what is the structure of a secondary amide?
what is the structure of a tertiary amide?
what are primary amides made from?
ammonia + acyl chloride
why are primary amides made from acyl chlorides and not carboxylic acids?
carboxylic acids do not react easily with ammonia but acyl chlorides do, and they produce the same product
what are secondary amides derived from?
primary amine + carboxylic acid
what type of reaction produces amides?
condensation reaction
what is the by-product of the reaction to produce amides?
hydrogen chloride
what is the equation for the hydrolysis of primary amides in acidic conditions?
RCONH2 -> RCOOH + NH4
what is the equation for the hydrolysis of primary amides in alkaline conditions?
RCONH2 -> RCOO- + NH3
what is the equation for the hydrolysis of secondary amides in acidic conditions?
RCONHR| -> RCOOH + R|NH3+
what is the equation for the hydrolysis of secondary amides in alkaline conditions?
RCONHR| -> RCOO- + R|NH2
what is a conjugate base?
an acid that has donated a H+
why are conjugate bases basic?
as the acids have donated a H+, they can now re-accept them, making them basic
what strength of conjugate bases do strong acids form and why?
weak conjugated bases
strong acids fully dissociate so are less likely to re-accept the proton
what is the more common name for aminocarboxylic acids?
amino acids
what is an alpha amino acid?
an amino acid with a central carbon atom, which is attached to the amine and carboxyl groups
what is an alpha carbon in amino acids?
the central carbon - the one attached to the -COOH and amine groups
what is a zwitterion?
a molecule with two functional groups, where one it positive and one is negative
what is the overall charge of a zwitterion?
neutral
which amino acid isn’t chiral and why?
glycine, the R group is a H so the alpha carbon is bonded to 2 H groups
what is the overall charge of amino acids?
neutral
how do amino acids act in basic conditions?
as an acid
how do amino acids act in acidic conditions?
as a base
how do amino acids form zwitterions?
as they receive or donate protons in aqueous conditions
what part of an amino acid accepts protons?
the NH2 group
what part of an amino acid donates protons?
the COOH group
draw an amino acid in zwitterion form
what type of intermolecular bonds do amino acid zwitterions form in aqueous conditions?
permanent dipole - permanent dipole
draw an amino acid in neutral, acidic and basic conditions
how do amino acids act as buffers?
the zwitterions buffer the solution by forming an acidic or basic ion, depending on the pH, to form an equilibrium
where are peptide bonds formed on amino acids?
between the -NH2 and -COOH
draw a peptide link between two amino acids
what type of reaction forms peptide bonds?
condensation reactions
how are dipeptides names?
the first 3 letters of each amino acid in order of bonding
what does chiral mean?
non-superimposable
what is a chiral centre?
a molecule bonded to 4 different groups
what are enantiomers?
a pair of molecules that are mirror images of each other
what is an essential amino acid?
an amino acid that can only be obtained through diet
what is a non-essential amino acid?
an amino acid that can be synthesised by the body
