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20 Cards in this Set
- Front
- Back
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Alanine
Ala A |
Aliphatic
No reactive groups Non-polar Interact favourably with other non-polar groups. |
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Arginine
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Capped with guanidino group.
group - planar stabilised by resonance. -Charge is delocalised over whole group. -ionised at physiological pH to NH-C-(NH2)2 + |
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Asparagine
Asn N |
Not very chemically reactive
Polar H bond donor and acceptor amide is planar (partial double) |
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Aspartate (Aspartic acid)
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Completely ionised, negative charged and exist as resonance @ physiological pH
Very polar Often act as chelators of metal ions eg Calcium |
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Cysteine
Cys C |
Non polar/polar
Very reactive in depronated form = use in active sites. C-SH group = sulfhydral |
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Glutamate (Glutamic acid)
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Completely ionised, negative charged and exist as resonance @ physiological pH
Very polar Often act as chelators of metal ions eg Calcium |
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Glutamine
Gln Q |
Not very chemically reactive
Polar H bond donor and acceptor amide is planar (partial double) |
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Glycine
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Aliphatic
No reactive groups Non-polar Much less restriction on phi and psi (steric reasons) and so make left and right handed turns in proteins. |
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Histidine
HIS H |
Imidazole ring- H acceptor(nucleophile) or donor(electrophile)
Therefore highly used in enzyme active sites. Hydrogen can be on either N. It is an electrophile when both Nitrogens have Hydrogens --> charged (+1) and also resonance with charged form of HIS (refer to lec) Nitrogen without H has lone pair on outside and has the double bond. |
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Isoleucine
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Aliphatic
No reactive groups Non-polar Interact favourably with other non-polar groups. extra chiral centre |
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Leucine
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Aliphatic
No reactive groups Non-polar Interact favourably with other non-polar groups. |
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Lysine
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Long aliphatic side chain.
Amine cap - -very polar and almost completely ionised to C-NH3+ --> thus positively charged. |
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Methionine
Met M |
Non-polar
Not Particularly reactive |
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Phenylalanine
Phe F |
Non-polar
Unreactive Absorbs a little UV light. |
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Proline
Pro P |
Aliphatic
No reactive groups Non-polar Interact favourably with other non-polar groups. No NH group: imino acid So can't act as backbone H-bond donor Very limited rotation so restricted Phi to ~ -60 peptide bond usually trans 1:1000 but 1:4 for X-Pro bond. |
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Serine
Ser S |
Not very chemically reactive.
H-bond donor or acceptor (OH --> OH2 or O) Polar |
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Threonine
Thr T |
Not very chemically reactive.
H-bond donor or acceptor (OH --> OH2 or O) Polar extra chiral centre |
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Tryptophan
Trp W |
Has Indole ring(first ring)
Largely non-polar Rarest side chain Electron Rich = interact with electron poor like arginine Absorbs UV light and is fluorescent. Spectral properties are sensitive to immediate surroundings = can tell if buried or exposed in a protein. |
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Tyrosine
Tyr Y |
Largely non-polar except for OH
OH can hydrogen bond hydroxyl group has pKa ~10 Absorbs UV light and fluorescent Spectral properties are sensitive to immediate surroundings = can tell if buried or exposed in a protein. |
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Valine
Val V |
Aliphatic
No reactive groups Non-polar Interact favourably with other non-polar groups. beta branched - branched at beta carbon. |
