20 Amino Acids Structures/Properties

Question 1

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 1

Glycine; Gly; n/a; hydrophobic Gly is sly & slips by with nothing but an H

smallest side chain

nonpolar but not very hydrophobic either

Adds to the FLEXIBILITY of plypeptides

Question 2

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 2

Alanine, Ala, n/a, Hydrophobic Al has a simple structure

Question 3

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 3

Valine; Val; n/a; Hydrophobic R group looks like a V

Question 4

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 4

Leucine; Leu; n/a; Hydrophobic LONG Valine

Question 5

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 5

Isoleucine; Ile, n/a, Hydrophobic Isolated/lopsided Leucine

Question 6

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 6

Phenylalanine; Phe; n/a; Aromatic

Phenyl + alanine

Question 7

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 7

Tryptophan; Trp; n/a; Aromatic (W)

TWYPtophan - chubby bunnies

big fat ring structure looks like a turkey

complicated & tryps you up

Question 8

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 8

Tyrosine; Tyr; 10.46; Aromatic

My eyes (phenyl ring) ar -OH so tired

Question 9

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 9

Histidine; His; 6.04; Basic

can be + OR neutral

2 double bonds & 2 NH’s

I’m a double sneezer -> need antihistamine

can serve as proton donor & proton acceptor - has innate buffering ability

can coordinate with metals

Question 10

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 10

Serine; Ser; n/a; Hydrophilic

“Sir”

“-OH AL, stop that”

Hydroxyl + Alanine

(pKA too high for OH to dissociate in the body)

Question 11

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 11

Threonine; Thr; n/a; Hydrophilic

1 C with THRE 3 side chains (OH, CH3, H)

only T without a Y so NOT Ar

(pKA too high for OH to dissociate in the body)

Question 12

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 12

Methionine; Met; n/a; Hydrophobic

thi = sulfur

C-C-S-C

*starts every protein

Question 13

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 13

Cysteine; Cys; 8.37; Hydrophilic (keep in mind disulfide bridges)

Sistine Chapel -> burning sulfer in Hell/strucure looks like a cross

can form Disulfide bonds like “God touching Adam”

involved in apoptotic cell death

good metal ion coordinator

Question 14

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 14

Aspartate/Aspartic Acid; Asp; 3.90; Acidic

only 2 C’s = spartan -> fewer luxuries

Question 15

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 15

Glutamate/Glutamic Acid; Glu; 4.07; Acidic

gluttonout take 3 C’s

the C=O need a mate -> O-

Eh? -> (E)

*long aspartate, Extra Tail

Question 16

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 16

Asparagine; Asp; n/a; Hydrophilic

(N) because of NH2

only 2 C’s becaue spartan = fewer luxuries

Asparate with Amide on the end

add a G - so fly like a G6, no charge because famous

Question 17

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 17

Glutamine; Gln; n/a; Hydrophilic

gluttonous taking 3 c’s

amine = NH2 group

amie derivative of glutamate

(Q)tamine rhymes with Glutamine

Question 18

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 18

Lysine; Lys; 10.54; Basic

long 4 C sword with sharp NH3+ tip for lysing everything

Question 19

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 19

Arginine; Arg; 12.48; Basic

surrounded by N’s

Arg - like a pirate -> 3 C’s & 3 N’s

Question 20

Name this Amino Acid, 3 letter abbreviation, pKa, and Category

Answer 20

Proline; Pro; n/a; Hydrophobic

3 C chain in closed loop with N

found in turns

*weird, just memorize*

Question 21

Name the 6 nonpolar/hydrophobic aliphatic Amino Acids

Answer 21

Glycine

Alanine

Valine

Proline

Leucine

Isoleucine

Methionine???

Nonpolar/hydrophobic

tend to cluster within proteins - think a micelle

Stabilize structure through their hydrophobic interactions

Question 22

Name the 6 polar/hydrophillic uncharged Amino Acids

Answer 22

Serine (pKA too high to dissociate in the body)

Thereonine (pKA too high to dissociate in the body)

Cystine

Proline

Asparagine

Glutamine

Question 23

Name the 3 Aromatic Amino Acids

Answer 23

Phenylalanine

Tyrosine

Tryptophan

**All have Y’s

Try Trypping on Phentoin

**Nonpolar/hydrophobic

phenyl ring allows for stacking interaction with STRONG hydrophobic interaction

Question 24

Name the 3 positively charged Amino Acids (Hydrophillic & Basic)

Answer 24

“HAL”

Histidine

Arginine

Lysine

very hydrophilic

all can Hydrogen bond

+ charge enables to form IONIC bonds with negative AA

Question 25

Name the 2 negatively charged Amino Acids (Hydrophilic & Acidic)

Answer 25

Aspartate/Aspartic Acid

Glutamate/Glutamic Acid

very low pKa -> dissociate & become negative in the body’s pH

Question 26

Special Amino Acids

Answer 26

Glycine = simplest

Cystein = creates disulfide bonds

Proline = allows for turns in protein due to structure; reduces structural flexibility b/c of rigid ring side chain

Methionine = useful for radioactive labeling with S(35)

Question 27

What are the Acidic/negative side chain Amino Acids

Answer 27

Aspartate/Aspartic Acid (D)

Glutamate/Glutamic Acid

Question 28

What are the basic/positive side chained Amino Acids

Answer 28

HAL

Histadine (R)

Arginine (H)

Lysine (K)