Unit 6 (Lesson 34 - 39) Flashcards
amines react as () with moderate and strong acids
bases
amine: acid/base reactivity trends
- EDG that donate via resonance increase basicity
- alkyl groups that donate electrons increase basicity
- sp3>sp2>sp for basicity
factors that affect base strength of amine
resonance
induction (pulling away) /hyperconjugation (donating)
hybridization (electronegativity)
what do you look for first
resonance – electron donating groups increase basicity - more so than alkyl groups
nitriles can reduce with () to form ()
LIALH4, H3O+ or H2 Pd/C
primary amine
nitro groups can reduce with () to form ()
H2 Pd/C or Zn HCl (aq)
aryl amine
can catalytic hydrogen reduce both imines and enamine
yes
amides can be reduced with () to form ()
LiAlH4
amines
neutral amines are ()
- weak bases
- they can use their nitrogen to accept a proton, becoming a protonated series
amines can deprotonate carboxylic acids
irreversibly
amines can deprotonate strong acids
Irreversibly
electron donation
increases amine basicity
electron withdraw
decreases amine basicity
the stronger the inductive atom/group, (EWD)
the more weakly basic the nitrogen atom
localized lone pair on nitrogen
- more readily shared
- more basic
true/false: alkyl amines are more basic than amide nitrogens
true
amino acids
the monomeric units that make up polyamides or proteins
pka = pH (amino acids)
were half the species is protonated and half is deportonated
isoelectric point
is pH where overall charge = 0
all amino acids are chiral
except for glycine
what interactions drive the folding of peptides into their tertiary, and then quaternary structures
H-bonds
hydrophobic interactions
-S-S-
electrostatic interactions
() is the only L-amino acid with an R configuration
cysteine
from Henderson-Hasselbalch: when pH=pKa
50% in acidic and 50% in basic form –> draw 2 species
when the side chains are not ionizable, the PI is ()
the average of the pKa’s of the carboxylic acid and the amine
aliphatic
not aromatic
if pH < pKa
protonated
if pH > pKa
deprotonated
what is an amino acid
a carboxylic acid possessing a protonated amino group at is alpha carbon
at physiological pH (7.3-7.4)
amino acids exist as zwitter ions (possesing both positive and negative charges)
D-Amino Acids
R configuration at the alpha carbon
L-Amino Acids
S configuration at the alpha carbon
priority for amino acid
1 - amino group
2 - carboxyl group
3 - R group (side chain)
4 - hydrogen
carbohydrates
naturally occuring compounds with C, H, O: often with the empirical formula CH2O and a molecular formula of (CH2O)n
D-glucose fisher projection
4 bars
3rd carbon (2nd bar)s is OH-H (rest of bars are (H-OH)
monosaccharides
simple sugars which cannot be broken down by hydrolysis
- glucose
disaccharides
dimers of monosacharides
- cellobiose
oligosaccharides
contain 3 to 8 monosaccharides
- raffinose
polysaccharides
contain > 8 monosaccharides
- cellulose
top of fisher projection
most oxidized carbon
horizontal right
- always wedge
- down on conformer
horizontal left
- always wedge
- up on conformer
fisher projections can be rotated:
180 degrees but not 90 degrees
rotation of 90 degrees
creates the enantiomer
when asked about what structures have the same configuration what do you do
use R and S
an aldohexose is a sugar containing () carbons and an ()
6, aldehyde
the ending ose
indicates a carbohydrate
an aldose
contains an aldehyde
a ketose
contains a ketone
L configurations are
naturally occuring in amino acids
R configurations are
naturally occurring in sugars
enantiomers
every center changes
when multiple stereocenters are present,
D or L refers only to the second to last carbon
carbohydrates with a hydroxyl to the right on the last C in the fischer projection are
D
carbohydrates with a hydroxyl to the left on the last C in the Fischer projection are
L
aldotetroses
2 asymmetric carbons
2^2 = 4 stereoisomers
4 carbons
aldopentoses
3 asymmetric carbons
2^3 = 8 stereoisomers
5 carbons
aldohexoses
4 asymmetrical carbons
2^4 = 16 stereoisomers
6 carbons
when D-ribose is added to an aqueous NaOH solution,
it undergoes rearrangement
