Where can I buy these cables?

I have opened up my Lenovo b50-45 laptop and I have lost the cables that go from the motherboard to the the hard drive and to the dvd/cd drive. Where can I buy these cables?

Radioshack, ebay, amazon. Your friendly local electronics shop.

It is just a matter of identifying what type of connector it is using… A quick google suggests it uses an mSATA connector, but do look at the back of the drive before ordering.

That was very careless to lose those cables. You now have a big problem trying to find a supplier. You can try eBay or Amazon for spares, but to be sure Levono spares should have them. The problem is they tend to supply to the trade only not the end user, here is a link to Levono. You need to Find the FRU (field replacement unit) number before you place your order.
http://www.lenovo.com/...com/uk/en/
https://support.lenovo.com/...artslookup