The basic structure of a plant cell is shown below – the same plant cell, as viewed with the light microscope, and with the transmission electron microscope.
Animal and plant cells have certain structures in common.
|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||Its structure is permeable to some substances but not to others. It therefore 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 organelles where protein synthesis occurs.|
Plant cells also have additional structures:
|Chloroplasts||Organelles that contains the green pigment, chlorophyll, which absorbs light energy for photosynthesis. Contains the enzymes needed for photosynthesis.|
|Cell wall||Made from cellulose fibres it strengthens the cell and supports the plant.|
|Permanent vacuole||Filled with cell sap to help keep the cell turgid.|
Animal cells may also have vacuoles but these are small and temporary. In animals, they are commonly used to store or transport substances.
There are many different types of cells in plants. Each type is specialised to do a particular role and ensures that the organism functions as a whole.
The root hair cell has a large surface area to provide contact with soil water.
It has thin walls so as not to restrict the movement of water.
Root hair cell
There are no top and bottom walls between xylem vessels, so there is a continuous column of water running through them.
Their walls become thickened and woody. They therefore support the plant.
Strands of cytoplasm run through holes in the sieve plates, connecting the sieve tubes that make up the phloem.
Dissolved sugars and amino acids can be transported both up and down the stem.
Companion cells, adjacent to the sieve tubes provide energy required to transport substances in the phloem.
Plant cells can be observed in a laboratory, using a light microscope.