The cell is the basic unit of life. Most cells are extremely small, so they are invisible without a microscope. All organisms are formed by cells. Actually, a cell is the smallest part of any living organism. Each cell is formed by many parts. They include:
- Cell membrane;
- Nuclear Membrane;
- Endoplasmic Reticulum;
Most cells feature the same characteristics. So, the cell is covered by a cell membrane. It can come in different shapes. The inside of a cell is called the protoplasm.
The cell membrane surrounds the outside of the cell. This is a very thin membrane. It allows certain substances to pass in and out. Such substances may include foods or oxygen. Inside the cell membrane, there are many structures known as organelles. The cytoplasm is formed by water and organelles. The nucleus is also found inside the cell membrane. This actually is the control center of the cell. Inside the nucleus there are located chromosomes, which contain the cell’s genetic information. The entire function of the animal cell is explained in the video below:
Cells vary a lot when it comes to size. They carry thousands of biochemical reactions each minute, this way perpetuating life. Cells work in the human body without us having an idea about the complexity of this process.
Here are some fascinating facts you should know about animal cells:
- The smallest cell measures 0.00001 mm in diameter.
- The largest cells are the nerve cells that run down a giraffe’s neck.
- Liver cells may be ten times larger than heart cells.
- Cells can present numerous differences in size and shape.
- Each cells is a model of independence and self-containment.
- Cells can join, communicate and coordinate with other cells.
- Inside the human body, there are about 20 to 30 trillion cells.
- Dozens of different kinds of cells are organized in tissues.
- The components of cells are molecules. They are structures formed by the union of atoms.
- The main molecules that underlie cell structures are proteins, nucleic acids, carbohydrates and lipids.
- Biochemical reactions in cells are guided by enzymes.
- DNA, meaning the nucleic acid deoxyribonucleic acid, contains the hereditary information of cells.
- RNA, meaning the ribonucleic acid, works with DNA to built the proteins that cells need.
Cells are basic structural and functional units of living organisms. The cell was first discovered in 1665. The cell theory was developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann.