Putting in RAM with a higher speed

The frequency rating on RAM is analogous to the top speed of a car, if it's max speed is (for example) 250 km/h, it can drive up to 250 km/h, but it won't break if u drive at 25 km/h.

Same for RAM. As long as it's the same DDR3 Standard, it will run, regardless of how high the max clock speed is.

It depends on manufacturer of your memory and how much specific stick is compatible with your memory controller and/or with graphics chip.

For example, my MacBook Pro mid 2010 13" (MacBookPro7,1) did not support Hynix 4GB PC3-12800 DDR3 1600 MHz sticks if used alone or 4GB+4GB, they work only if coupled (2GB+4GB) with pre-installed 2GB 1033 MHz sticks from Samsung.