i cant update my macbook Pro Black from snow leopard 10.6.8 to yosemite.

I have read the specs and everything seems fine. I have snow leopard 10.6.8 and when I try and update i get a message from the applestore app to say it cant be installed on this laptop.

Please can anyone advise me on that I should do.

MAC OS Build 10.6.8

Model Name: MacBook

Model Identifier: MacBook4,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 3 MB

Memory: 2 GB

Bus Speed: 800 MHz

Boot ROM Version: MB41.00C1.B00

SMC Version (system): 1.31f1