If by straightening you mean with a flat iron then no, it won't cause your hair to lose curl.
If you know how to curl your hair with a straightening iron...then I would really reccomed a CHI straightner.
It would be hard to explain to you how to do it... but Go on Youtube.com and search for "How to use a straightening iron to curl your hair" tons of videos pop up
Of course, you can curl even after a day!
You curl your hair everywhere and then bum it like a slag
curl your hair
curly
curly
Disulfide bonds in hair help maintain its shape and structure. In curly hair, these bonds play a key role in determining the curl pattern and strength of the curls. When disulfide bonds are broken and reformed during styling processes like perming or straightening, they can alter the natural curl pattern of the hair.
You can use a straightening iron.
brush and curl it with a curl in iren every morning and night
American Curl breeds of cats have amazing curly coats.
Its naturally curly