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30 Cards in this Set
- Front
- Back
The internal salt of an amino acid is given the special name _______.
(no net charge) |
Zwitterion
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Amino acids share many similarities in characteristics with what?
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Salts
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Amino Acids:
____ at room temp. ____ melting points. ____ in water. ____ in ether + hydrocarbon solvents. |
Crystalline Solids
High Melting pts. Fairly soluble in water. Insoluble in ether + hc solvents |
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Nonpolar Side Chains?
(A G I L M F P W V) |
Alanine (A)
Glycine (G) Isoleucine (I) Leucine (L) Methionine (M) Phenylalanine (F) Proline (P) Tryptophan (W) Valine (V) |
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Polar Side Chains?
(N Q S T) |
Asparagine (N)
Glutamine (Q) Serine (S) Threonine (T) |
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Acid Side Chains?
(D E C Y) |
Aspartic Acid (D)
Glutamic Acid (E) Cysteine (C) Tyrosine (Y) |
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Basic Side Chains?
(R H K) |
Arginine (R)
Histidine (H) Lysine (K) |
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A compound that contains a carboxyl group and an amino group.
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Amino Acid
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Most significant amino acids in the biological world.
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alpha- amino acids
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Monomers of proteins
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alpha-amino acids
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All protein derived amino acids except ______ are chiral.
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Glycine (G)
H2NCH2COOH |
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Vast majority of carbohydrates in the world are what series?
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D-series
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Vast majority of a-amino acids are which series?
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L-series
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Protein Derived Amino Acids:
All 20 protein derived amino acids are _______ amino acids. |
alpha
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What does it mean?
"alpha-amino acid" |
The amino group is located on the carbon alpha to the carboxyl group
H2CCHCOO - | NH3 + (A) -? |
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Protein Derived Amino Acids:
Out of the 20 most common; which is the only protein derived amino acid that has a secondary alpha-amino group? |
Proline (P)
draw it. |
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Protein Derived Amino Acids:
With the exception of _____ the alpha-carbon of each amino acid is chiral. |
Glycine (G)
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Protein Derived Amino Acids:
All 20 have an alpha-carbon that is D or L series? |
L-series
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Protein Derived Amino Acids:
All 20 except which alpha-amino acid is S-configuration? Why? |
L-cysteine
Due to priority rules: the presence of sulfhydryl group makes it R. |
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Protein Derived Amino Acids:
Which two alpha-amino acids contain a second chiral center? |
Isoleucine ( I ) + Threonine (T)
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Protein Derived Amino Acids
Sulfyhdryl group of _______, the imindazole group of _______, and the phenolic hydroxyl of _______; are partially ionized at a ph of ___. (Ionic is not major form at this ph) |
Cysteine (C)
Histidine (H) Tyrosine (Y) 7 |
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These two amino acids are found in the liver and play an integral part in the urea cycle.
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L-ornithine
draw them L-citrulline |
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These amino acids are found in the thyroid tissue and they stimulate metabolism in other cells.
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L-thyroxine, T4
draw them L-Triiodothyronine, T3 |
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A major neurotransmitter in the brain's Central Nervous System. Synthesized by ezyme catalyzed decarboxylation of glutamic acid.
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Gamma-Aminobutyric Acid
draw both |
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What is the average pka value of the 20 common amino acids' protonated alpha-carboxyl groups?
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2.19
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True or False
Most common low molecular weight aliphatic carboxylic acids are stronger than protonated alpha-carboxyl groups of the 20 amino acids. Explain why. |
False
Inductive effect from the alpha-ammonium group makes them stronger acids. |
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Which is stronger?
Side chain carboxyl groups or low mw aliphatic carboxylic acids? |
Side chain carboxyl groups
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What is the average pka for the 20 amino acids alpha-ammonium groups?
(Slightly stronger than primary aliphatic ammonium ion.) |
9.47
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The basicity of the guanidine group of arginine is attributed to ______ stabilization of the protonated form in comparison to the neutral form.
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Resonance
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Why is the imindazole group on the side chain of histidine basic?
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The pair of electrons that is not part of the aromatic sextet is responsible for the basicity.
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