Amino Acids Flashcards
What are the 4 distinct structures of an Amino Acid?
What are the rules for a fisher projection?
Horizontal lines = groups coming towards you.
Vertical Lines = groups going away from you.
Intersection =Alpha Carbon(Chiral carbon)
When placed in water, what happens to amino acids?
What are the 7 amino acids with an aliphatic, nonpolar side chain.
Aliphatic= Carbons that form linear/branched structure NO rings.
What is this amino Acid? What type of molecule is it?
P (Pro) Proline.
Aliphatic (Ring forms with amino group NOT itself)
Nonpolar side chain
Unique: its side chain, makes a ring by bonding with its main chain nitrogen.
What is this amino Acid? What type of molecule is it?
G (Gly) Glycince.
Aliphatic
Nonpolar side chain.
Unique: glycine has no side chain. It is achiral.
What is this amino Acid? What type of molecule is it?
I (Ile) Isoleucine
Aliphatic
Nonpolar side chain
Unique: is one of two amino acids with a chiral chain.
What is this amino Acid? What type of molecule is it?
A (Ala) Alanine
Aliphatic
Nonpolar side chain.
What is this amino Acid? What type of molecule is it?
V (Val) Valine
Aliphatic
Nonpolar side chain
What is this amino Acid? What type of molecule is it?
L (Leu) Leucine
Aliphatic
Nonpolar side chain
What is this amino Acid? What type of molecule is it?
M (Met) Methionine
Aliphatic
Nonpolar side chain
What are the 5 amino acids with an uncharged, polar side chain?
What is this amino Acid? What type of molecule is it?
S (Ser) Serine
Uncharged
Polar side chain
What is this amino Acid? What type of molecule is it?
T (Thr) Threonine
Uncharged
Polar side chain
Unique: one of the two amino acids that have a side chain, which is chiral.
What is this amino Acid? What type of molecule is it?
C (Cys) Cystine
Uncharged
Polar side chain
Unique: 1. Can form Disulfide bonds, 2. S is good nucleophile. 3. Good in coordinating metals 4.
pK of the SH is ~8.3
What is this amino Acid? What type of molecule is it?
N (Asn) Asparagine
Uncharged
Polar side chain
What is this amino Acid? What type of molecule is it?
Q (Gln) Glutamine
Uncharged
Polar side chain
What are the 3 amino acids with positively charged side chains?
What is this amino Acid? What type of molecule is it? What’s the pK?
K (Lys) Lysine
Positive charged side chain
pK=10
What is this amino Acid? What type of molecule is it? What’s the pK?
R (Arg) Arginine
Positively charged side chain
pK=12.5
What is this amino Acid? What type of molecule is it? What’s the pK?
H (His) Histidine
Positively charged side chain (Generally neutral but about 10% is positive generally)
pK= 6
Unique: 1. The PK being six means that at a neutral pH the ring is both protonated and unprotonated. At a pH below the PK a larger fraction is protonated than unprotonated.
2. It is often involved in acid base catalysis.
3. The side chain is good and coordinating metals.
What are the two amino acids with a negatively charged side chain?
What is this amino Acid? What type of molecule is it? What’s the pK?
D (Asp) Aspartate
Negatively charged side chain
Very hydrophilic
Occur often in active sites.
Can coordinate metals
pK= 3.9
What is this amino Acid? What type of molecule is it? What’s the pK?
E (Glu) Glutamate
Negatively charged side chain
Very hydrophilic
Occur often in active sites.
Can coordinate metals
pK= 4.2
Name the 3 amino acids with aromatic side chains. (What two are amphiphilic?)
The two are: Tyrosine and Tryptophan.
What is this amino Acid? What type of molecule is it? What’s the pK? What wave length does it absorb?
F (Phe) Phenylalanine
Aromatic side chain
pK unimportant.
Absorbs at 258 nm.
What is this amino Acid? What type of molecule is it? What’s the pK? What wave length does it absorb?
Y (Tyr) Tyrosine
Aromatic side chain
pK=10.1
nm not said yet
What is this amino Acid? What type of molecule is it? What’s the pK? What wave length does it absorb?
W (Trp) Tryptophan
Aromatic side chain
pK unimportant.
Nm=unkown rn
Test your amino acid memorization.
What does the imidazole group look like above the pKa? below?
What does the Guanidinium group look like above the pKa? below?
