Biology A level OCR - Eukaryotic Cell Structure Cheat Sheet

There are two fundam­ental types of cells: prokar­yotic and eukary­otic.

Prokar­yotes - unicel­lular organisms with an undivided cytoplasm. The cytoplasm is made of cytosol (water, salts and organic molecu­les).

Eukaryotic - multic­ellular organisms. Eukaryotic cells have a more complex inner structure (e.g. nucleo­plasm, cytopl­asm).

This topic is about the ultras­tru­cture of the cell (what can be observed with an electronic micros­cope).

A network of fibres found throughout eukaryotic cells' cytoplasm which provide stability and structure to the cell as well as hold organelles in place. It also controls cell and organelle movement.
It is made of three struct­ures:

Microf­ila­ments - Made from protein actin. Respon­sible for cell movement and cell contra­ction (during cytoki­nesis).

Microt­ubules - Determines the shape of a cell due to polyme­rised globular tubulin proteins. Used as tracks for the movement of organelles (e.g. vesicles). They also make up spindle fibres used on the separation of chromo­somes.

Interm­ediate fibres - Provide mechanical strength to cells and maintain their integrity.