"cis-gender" are you calling me a cis?

 22.6.6: web.psy/cis-gender/are you calling me a cis?:

. cis-gender people identify as 

the same gender they were assigned at birth, 

while transgender people identify as

a gender different from that assigned at birth.

[Canadian Med Assoc J JUNE 6, 2022]

https://medicalxpress.com/news/2022-06-transgender-sexual-minority-teens-high.html

. I wondered if that terminology was meant to

make straight people ask rhetorically:

"are you calling me a cis?"

but the source of that term actually comes from

their latin definitions.

. there may be trans-nationals

but there are no cis-nationals;

so why should there be cis-genders?

. some confusion comes because 

trans- has 2 meanings in Latin:

you can have a transnational corporation

because trans- can mean "beyond",

so a transnational is beyond national borders;

but you can also have a trans-gender,

because trans- also means "on the other side".

. trans-gender can mean "beyond gender"

if you are choosing to appear asexual or ambiguous,

but conventionally it means moving across genders,

going from one to the other.

the Latin:

https://www.etymonline.com

cis-:

"on the near side of, on this side," 

from Latin cis "on this side".

trans-:

"on the other side of, to go beyond," 

from Latin trans (prep.) 

"across, over, beyond".

my first experience with trans- and cis-

was in lipid chemistry:

. fats are composed of carbon chains;

a carbon has 4 connectors,

so it has 2 connectors for a carbon on either side,

and then 2 more connectors for hydrogens

which have only one connector.

. but the carbons involved in 

double bonds with other carbons,

have fewer connections for hydrogens.

. when the double bond happens between 2 carbons,

the chains are no longer straight because 

instead of a carbon bonding with 4 things 

all at right angles to each other,

they are now bonding to only 3 things:

2 carbons, and one other hydrogen.

. you have 2 choices for

how to position the carbon chains

that are on either side of a double bond.

the cis configuration:

. the carbon chains on the same side of the double bond,

relative to the hydrogens.

C-C-C-  C = C  - C-C-C

       H -                - H

the trans configuration:

. the carbon chains are on opposite sides of the double bond,

relative to the hydrogens.

            H -   C = C    - C-C-C

    C-C-C -   - H

. in the character drawings above,

keep in mind that a carbon has 4 connectors,

so if you have only a single bond (-) between C's,

rather than a double bond (=),

that implies there are connections to 2 H's 

that are not shown here for simplification.

. when the drawing writes:

           H -  C = C

   C-C-C -

that means that both the H and the C-C-C

are connecting with the C of "C =".

Cis–trans isomerism:

https://en.wikipedia.org/wiki/Cis%E2%80%93trans_isomerism

In the context of chemistry, 

cis 

indicates that the functional groups

are on the same side of some plane;

trans

means they are on opposing (transverse) sides. 

In general, cis–trans stereoisomers contain

double bonds that do not rotate, 

or they may contain ring structures, 

where the rotation of bonds is restricted or prevented.

Cis and trans descriptors are not used for 

cases where the two geometric forms easily 

interconvert, such as most 

open-chain single-bonded structures; 

instead, the terms "syn" and "anti" are used.

Donald A. Norman` The Design of Everyday Things[ad]