Mcat Amino Acids

Front 1

Strecker Synthesis

Back 1

Formation of amino acid from aldehyde or ketone.

1. NH3 in presence of H+

2. KCN in presence of H+

3. Hydrolysis to alpha amino acid

* more efficient, lots of protonating

Front 2

Gabriel Synthesis

Back 2

Formation of a primary amine from an alkyl halide using thalamide.

1. SN2 using thalamide as Nu to alkalate

2. Hydrolysis giving COOH and NH3 groups

3. Heat decarboxylates leaving alpha amino acid

Front 3

Non-Polar, aliphatic R groups

Back 3

No Polar bears in Las Vegas, plenty of Meth. Go to Alaska .

Isoleucine, valine, proline, methionine, glycine, alanine

Front 4

Aromatic R group Amino Acids

Back 4

Terrible Toilet Paper

Tryptophan, Tyrosine, phenylalanine

Relatively hydrophobic

Front 5

Polar, uncharged amino acids

Back 5

Supreme Court- Dont Charge the polar bears, they aren't guilty. (they're just MEAN-INES)

Serine, Cysteine, Threonine, Asparagine, Glutamine

Hydrophilic- because of the ability to form hydrogen bonds with water

Front 6

Positive Charged R groups

Back 6

Postive= LAugH

Lysine, Arginine, Histidine

*4 carbons

Front 7

Negatively charged R groups

Back 7

Negative= ArGggg

Aspartate, Glutamate

Front 8

Absolute configuration

Back 8

amine to the left (L), carboxyl up, R group down on a fischer projection. If amine in on the right (D) very rare in biological systems

Front 9

Dipolar/ Diprotic nature

Back 9

Amino acid can be in three forms

1. Acid Fully protonated NH3+ and COOH

2. Zwitter Ion- COO- and NH3+

3. Basic form COO- and NH3

Front 10

PI

Back 10

pH at equivalence point where Zwitter ion in present

Front 11

Glycine

Back 11

GLY

G

Front 12

Alanine

Back 12

ALA

A

non-polar, aliphatic

Front 13

Proline

Back 13

PRO

P

non-polar, aliphatic

Front 14

Valine

Back 14

VAL

V

non-polar, aliphatic

Front 15

Leucine

Back 15

LEU

L

non-polar, aliphatic

Front 16

Isoleucine

Back 16

ILE

I

non-polar, aliphatic

Front 17

Methionine

Back 17

MET

M

non-polar, aliphatic

Front 18

Phenylalanine

Back 18

PHE

F

Aromatic

Front 19

Tyrosine

Back 19

TYR

Y

Aromatic

Front 20

Tryptophan

Back 20

TRP

W

Aromatic

Front 21

Serine

Back 21

SER

S

Polar, uncharged

Neutral

Front 22

Threonine

Back 22

THR

T

Polar, Uncharged

Neutral

Front 23

Cysteine

Back 23

CYS

C

Polar, uncharged

neutral

Front 24

Asparagine

Back 24

ASN

N

polar, uncharged

neutral

Front 25

Glutamine

Back 25

GLN

Q

Polar, uncharged

neutral

Front 26

Lysine

Back 26

LYS

K

positive charged

hydrophilic

Front 27

Arginine

Back 27

ARG

R

positive charged

hydrophilic

Front 28

Histidine

Back 28

HIS

H

postive charged

hydrophilic

Front 29

Aspartate

Back 29

ASP

D

negative charge

hydrophilic

Front 30

Glutamate

Back 30

GLU

E

negative charge

hydrophilic

Front 31

Which amino acid is achiral?

Back 31

glycine

Front 32

L or D orientation?

Back 32

In humans amino acids are in L form

Example of D orientation are rare- some proteins in bacterial membrane

Front 33

R or S?

Back 33

All amino acids are S (counter-clockwise in fischer projection) with the exception of cystine

Front 34

PI (amino acids)

Back 34

The PI=Isoelectric Point

In neutral amino acids this is when the molecules are electrically neutral or the carboxyl group has deprotonated but the amine has not.

Front 35

Calculating pI

Back 35

the average of the closest pKa values.

Neutral amino acids pI ~6

Positive amino acids pI >6

Negative amino acids pI<6

Front 36

Negative Amino Acids are _____ because they give up _____ quickly and below pH of ___

Back 36

acidic, H+s, 7

Front 37

Postive amino acids are ______ because at neutral pH they are still accepting ____

Back 37

basic, H+