2.2 describe cell structures, including the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole

What you need to know for this is the layout of the cell, this is easiest done by diagram, but here are explanations:

Animal cell
A nucleus is in the centre of the cell; it is surrounded by cytoplasm; around the outside edge is the cell membrane.

Plant cell
A vacuole in the centre is surrounded by cytoplasm; with in this is the nucleus and chloroplasts; surrounding this is the cell membrane; and around that is the cell wall.

There are diagrams at the bottom of this page: http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/cells/cells2.shtml