What is the Cell Wall?

All plant cells are surrounded by a Cell Wall made mainly of Cellulose. Paper, which is made from Cell Walls, is also made of Cellulose. Cellulose belongs to a group of substances called Polysaccharides. Cellulose forms fibres that criss-cross over one another to form a very strong covering to the cell. This helps to protect and support the cell. Because of the spaces between the fibres, even very large molecules are able to go through the Cellulose Cell Wall. It is therefore said to be Fully-Permeable. Animal cells never have Cell Walls.

What is the Nucleus?

The Nucleus is where the information is stored which help the Ribosomes make the right sort of proteins. The information is kept in the Chromosomes, which are inherited for that organisms parents. Chromosomes are very long, but so thin that even Electron Microscopes can't see them properly. However, when the cell is dividing, they become short and thick, and can be seen by a good Light Microscope.

What is the Mitochondria (mitochondrion)?

Every cell has Mitochondria, because it is here that the cell releases energy from food. The energy is needed to help it move and grow. Mitochondria are sometimes called the 'powerhouses' of the cell. The energy is released by combining food with oxygen, in a process called Respiration. The moreactive a cell, the more Mitochondria it has. Mitochondria is plural for Mitochondrion

What are Ribosomes?

Ribosomes are very tiny, round objects, often attached to the Endoplasmic Reticulum. It is here that Proteins are made, by joining together smaller molecules called Amino Acids. To et Amino Acids inthe right order, the Ribosomes follow the instructions from the Nucleus.

What are Organelles?

All the structures within a cell are called Organelles. The Nucleus, Mitochondria (singular form Mitochondrion) and Ribosomes are all Organelles. Oranelles are structures in the cell that have special functions. Organeles are discrete.

What are Chloroplasts?

Chloroplasts will never be found in an animal cell. Most of the cells in the green parts of any plant will have them. Chloroplasts contain a green pigment called Chlorophyll. Chlorophyll absorbs sunlight, and the energy of the sunlight is then used for making food by means of Photosynthesis. Chloroplasts often contain Starch Grains, which have been made by means of Photosythesis. Animal cells never contain Starch Grains either.

What is the Endoplasmic Reticulum?

Endoplasmic Reticulum is a maze of membranes which runs all through the cytoplasm of any cell. They are assembly lines for making Fats and Proteins out of smaller molecules in the cell. Endoplasmic Reticulum is found in all cells.

What is a Vacuole?

A Vacuole is a space in a cell that contain a solution, it is also surrounded by its own membrane. Plant cells have very large Vacuoles, which contain a solution of sugars and other substances called cell sap. Animal cells have much smaller Vacuoles and may either contain food or water.

What is Cytoplasm?

Cytoplasm is a clear jelly. It is 70% water in most cells. It contains many substance dissolved in it, especially Proteins. It supports everything inside a cell, like the Nucleus and Mitochondria

What is the Cell Membrane?

All cells have a Cell Membrane on the outside, it is also called the plasma membrane. In a plant cell it is very hard to see because it is right up against a Cell Wall. The plasma membrane is a very thin layer made upof Proteins and Fats. It is very important because the it determines what goes in and come out of the cell. It is said to be Partially Permeable, which means that it will let some substances through but not others.

What is a Cell?

Every living thing is made up of cells. Cells are extremely small, so large organisms (animals or plants) can contain billions of cells. Some organisms are Unicellular, these are the Bacteria, Protozoa and some types of Algae. Unicellular means that the oraginsm has no Nucleus, Mitochondria, Chloroplasts or Endoplasmic Reticulum, but they have a cell wall.

As you should know by now, Cells are very small, so to see them clearly you need a special tool called a light microscope. It is named this because it shines light through the substance that you are looking at. Then it uses glass lenses to magnify and focus the image. To see even smaller things in the substance, you will need an Electron Microscope. This uses a beam of Electrons instead of light. The light microscope can only magnify about 400-1500 times, but the Electron Microscope can magnify from 40000-500000 times. This obviously mean that more detail will be shown inside the substance that you are exmining.