d-(redirected from R-)
Also found in: Medical.
In biochemistry, a symbol used as a prefix to indicate the spatial configuration of certain organic compounds with asymmetric carbon atoms. It is used if an organic compound has a configuration about an asymmetric carbon atom analogous to that of D-glyceraldehyde (the arbitrarily chosen standard), in which the hydroxy (OH) functional group is on the right side of the asymmetric carbon atom in a Fischer projection formula.
The symbol for dextrorotatory.
n., pl. Ds D's, ds d's.
1. the fourth letter of the English alphabet, a consonant.
2. any spoken sound represented by this letter.
3. something shaped like a D.
4. a written or printed representation of the letter D or d.d
(of a molecule) having a configuration resembling the dextrorotatory isomer of glyceraldehyde: printed as a small capital, roman character (disting. from l-).
dextrorotatory; dextro- (disting. from l-).
do (esp. before you): How d'you like them?
1. contraction of had: They'd already left.
2. contraction of would: I'd like to see it.
3. contraction of did: Where'd you go?
4. contraction of - ed: She OK'd the plan.
1. the fourth in order or in a series.
2. (sometimes l.c.) (in some grading systems) a grade or mark indicating poor or barely acceptable quality.
a. the second note of the ascending C major scale.
b. a tonality having D as the tonic.
4. (sometimes l.c.) the Roman numeral for 500. Compare Roman numerals.
5. Physics. density.
8. Brit. pence.
[< Latin denāriī]
9. Chiefly Brit. penny.
[< Latin denārius]
10. Physics. density.