Class Equivalent for function modules

Hi all,

Is there any pre-defined classes or methods in SAP for the below function modules :

1) C144_MATERIAL_PLANT_CHECK

2) MD_CONVERT_MATERIAL_UNIT

3) CS_BOM_EXPLOSION

4) CS_WHERE_USED_MAT

5) CONVERSION_EXIT_ALPHA_OUTPUT

6) CONVERSION_EXIT_ALPHA_INPUT

Pl help

Regards

Manigandan