It seems that its doing a if not this than that kind of a thing, but I know it´s not the traditional conditional. 

For example, 

Yeterli paran olup olmadığını biliyor musun? I know this is saying do you know if you have enough money or something along those lines

Kırmızı takımın kaybedip kaybetmeyeceğini bilmiyorum. I dont know if the red team lost or not?

-ip + the same verb in negative means ´whether or not´, so you are right Emily.