IGCSE Science/Section 2: Structures and functions in living organisms/Cell structure
Cell organelles: Small structure having definite shape and performing specific functions
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Simple_diagram_of_animal_cell_%28en%29.svg/300px-Simple_diagram_of_animal_cell_%28en%29.svg.png)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/5/5b/Simple_diagram_of_plant_cell_%28en%29.svg/300px-Simple_diagram_of_plant_cell_%28en%29.svg.png)
They are embedded in the cytoplasm, These structures are called cell organelles. Most cells have these organelles:
Name | Function |
---|---|
Nucleus | It regulates all important activities of the cell and plays an important part during cell division. |
Cytoplasm | a place for chemical reactions to happen, and it contains enzymes which speed up these reactions |
Cell membrane | It allows only certain substances to pass through small pores on it and protects the inner cell contents. |
Mitochondria | It perform cellular respiration, referred as powerhouse of the cell. |
Plants cells have:
Name | Function |
---|---|
Cellulose cell wall | It gives a definite shapes to the cell , allows all substances to pass through it and protect the inner cell contents called protoplasm. |
Plastids | They are of 3 types:
i)Chloroplast- It can trap solar energy and covert it into chemical energy in the form of food through the process of photosynthesis. ii)Chromoplast-It contains coloured(red, yellow, orange)pigments that impart colour to flowers and fruits. iii)Leucoplast-It is colourless pigment that store food in the form of starch, proteins and fats. |
Vacuole | It stores sugar ,mineral and water in the form of cell sap and maintain the shape of cell. |
Yeast cells have:
Name | Function |
---|---|
Chitin cell wall | to keep the structure of the cell |
Vacuole | to store nutrients and food |
Animal cells only have the basic organelles, but plants have all the basic organelles and some more: a cell wall, chloroplasts and a vacuole:
![Diagram showing the parts of animal and plants cells. Plant-only organelles are shown in green.](http://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Differences_between_simple_animal_and_plant_cells_%28en%29.svg/850px-Differences_between_simple_animal_and_plant_cells_%28en%29.svg.png)