BIOL 363 Kenyon College

Amino Acids on Earth
by Annie

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Cysteine	Abbreviations: Cys, C
OSU Tutorial	Structure from OSU Tutorial

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1.  The properties of Cysteine are:

• Slightly polar
• Functional sulfur group
• Forms disulfide bonds
• Can form H bonds as a donor or receptor

2.  A derivative of Cysteine would be:

• N-acetyl-L-cysteine (NAC), a commonly sold supplement, has an added acetyl group.

3.  An interesting biological or pharmaceutical role of this cysteine derivative is:

• Supplemental cysteine has many therapeutic roles in human medicine.  Cysteine has been shown to improve respiratory and cardiovascular disease, as well as prevent Acetaminophen poisoning.  Studies are currently being conducted to examine the uses of cysteine for HIV patients.

4.  On a biosphere on a distant planet outside our solar system, a different but related amino acid is found:

· It has been reported that an isocysteine amino acid exists on the planet Queloz.  The structure is similar to isoleucine, but with an SH group instead of the final methyl. This amino acid still has the important functional sulfur group for disulfide bonding, but an additional methyl group creates some steric hindrance.

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