What is a cell?
All living organisms on Earth are made of really tiny particles called cells. Cells are the basis which makes up the structure of all living beings- all animals and all plants. Cells can only be seen under a microscope. Cells join together to form tissues which join together to make organs, an organic system which makes a living organism.
Plant cell structure and functions:
- The plants cell has a cell wall. This wall protects the contents on the cell and also limits a cell size. It is made up of chemicals like cellulose; an important sugar glucose for plants.
- Next is the cell membrane which is a thin layer of protein and fats and allows only few substances to pass through it.
- Chloroplast is a disc shaped organelle containing the Chlorophyll which is a molecule inside the cell that plants use to make food- the process of photosynthesis. It absorbs sunlight to turn water and carbon dioxide into sugar and oxygen.
- Plant cells contain the mitochondrion which is a spherical or rod shaped organelle that converts energy stored in the form of glucose.
In the center is the nucleus which controls all the functions of the cell and is surrounded by a nuclear membrane.
- They also have a permanent vacuole that takes up 90% of the cell volume and it helps the cell be turgid- swollen with water.
Animal cell structure and functions:
- The animal cell contains an external membrane which gives shape to cells and controls movement of materials like oxygen and carbon dioxide to pass in and out of cells.
- The central part of the cell is the nucleus which has a small structure called the chromosome in it. These chromosomes carry genes which are responsible for our hereditary characters passed on from our parents and ancestors.
- The cell contains an endoplasmic reticulum which is a tube like structure connecting different parts of a cell and helps them to carry materials.
- The mitochondria are like a power house of a cell. They are found in large numbers and help in respiration process of a cell that helps in energy formation.
- Cells also contain Lysosomes which have enzymes that help in digestion of food.
Difference between plant cell and animal cell
Animal cells do not have a cell wall or chloroplasts but plant cells do. Animal cells are round and irregular in shape but plants cells are rectangular and have a fixed shape. Animal cells contain lysosomes which are absent in plant cells. Animal cells have one or more small vacuoles but plant cells have only one big vacuole.