UPDATE: to address tormuse’s comments below.<\/p>\n
This discussion came out of a comment I made about the usage of ‘cis’ to refer to people whose gender identity is more matching with their gender assigned at birth*.<\/p>\n
I said:<\/p>\n
“The chemist in me is glad that this word is being used in this way. :)”<\/p>\n
And DM replied, asking about the ‘difference between Cis\u2013trans isomerism and chirality’.<\/p>\n
Not knowing if this was a serious question, and not wanting to derail a trans- issue conversation with chemical pedantry, I’m putting my answer in this blog post:<\/p>\n
Don’t know if this is a serious question, but I’ll bite. Cis\/Trans isomerism (generally) has to do with two Carbons connected by a double bond, with different things at R1\/R2\/R3\/R4.:<\/p>\n
\r\nR1 \u00a0 \u00a0 R3\r\n \\ \u00a0 \/\r\n C=C\r\n \/ \u00a0 \\\r\nR2\u00a0\u00a0\u00a0\u00a0 R4\r\n\r\nR1 R4\r\n \\ \/\r\n C=C\r\n \/ \\\r\nR2 R3\r\n<\/pre>\nThese two molecules have the same chemical composition, but because the C=C bond is rigid and does not rotate, they can have different chemical properties.<\/p>\n
Chirality is a little bit more difficult to explain using 2-D ASCII Art, but basically:<\/p>\n
\r\n R1\r\n \\\r\nr4--C--R3\r\n \/\r\n R2\r\n<\/pre>\n(With r4 at the back, behind the C, with R1\/R2\/R3 sticking out slightly from the page. #limitationsof2d)<\/p>\n
Contrast with:<\/p>\n
\r\n R1\r\n \\\r\nr4--C--R2\r\n \/\r\n R3\r\n<\/pre>\nWhich is a non-superimposable mirror image in 3-D. Even if R1\/R2\/R3 rotate around the r4 axis, they two molecules will never have exactly the same chemical characteristics (cf. Thalidomide)<\/p>\n
*I’m sure I’m using some of these words incorrectly or imprecisely. Please comment to correct me!<\/p>\n","protected":false},"excerpt":{"rendered":"
UPDATE: to address tormuse’s comments below. This discussion came out of a comment I made about the usage of ‘cis’ to refer to people whose gender identity is more matching with their gender assigned at birth*. I said: “The chemist in me is glad that this word is being used in this way. :)” And … Continue reading BOF VI: The Chemist in me:<\/span>