How exactly is symmetric key constructed from a passphrase?

[Calvert Remillard]

Consider following:

>  openssl aes-256-cbc -e -nosalt -pass pass:TEST -in FILE -out FILE.enc -P
key=033BD94B1168D7E4F0D644C3C95E35BF98D6BC98DA097F25270DEC053083AACF
iv =8BEAB338FC102B2A12933636C6EB7D59

How does passphrase "TEST" become
"key=033BD94B1168D7E4F0D644C3C95E35BF98D6BC98DA097F25270DEC053083AACF"?
How is it constructed? I've tried all supported hash functions (md5, sha1,
etc.), but they seem to produce different output.

Thanks a bunch in advance!