Cell structures
Organisms are made of cells. Most organisms are multicellular and have cells that are specialised to do a particular job. Microscopes produce magnified images of cells so we can study them in detail.
Animal cells
Almost all animals and plants are made up of cells.
Animal cells have a basic structure. Below the basic structure is shown in the same animal cell, on the left viewed with the light microscope, and on the right with the transmission electron microscope.
Mitochondria are visible with the light microscope but can't be seen in detail. Ribosomes are only visible with the electron microscope.
Cell structures and their functions
| Cell structure | How it is related to its function |
|---|---|
| Cytoplasm | A jelly-like material that contains dissolved nutrients and salts and structures called organelles. It is where many of the chemical reactions happen. |
| Nucleus | Contains genetic material, including DNA, which controls the cell's activities. |
| Cell membrane | It is permeable to some substances but not to others and so controls the movement of substances in and out of the cell. |
| Mitochondria | Organelles that contain the enzymes for respiration, and where most energy is released in respiration. |
| Ribosomes | Tiny structures where protein synthesis occurs. |
Most cells are specialised and are adapted for their function. Animals and plants therefore consist of many different types of cell working together.