A Cell is the basic structural and functional unit of organisms. The word ‘cell’ is derived from the Latin word “cella” which means “small room”. The type and number of cells in plants and animals vary. The cells can be classified in different ways. For example, based on the presence of a nuclear membrane, the cells are classified into two types i.e Eukaryotic and prokaryotic. Cells may also be classified based on the number of cells an organism is made of i.e unicellular, multicellular, and acellular.
Brief on Animal Cell
An animal cell is typically a eukaryotic type that has a well-defined nucleus and other membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. All cells are surrounded by a cell membrane or plasma membrane which separates the inner and outer components of the cell. The cell components are suspended in a fluid called cytoplasm.
Animals are multicellular organisms. The cells are specialized to perform various functions. Also, they look and function differently from each other even if they belong to the same organism.
Animal Cell Types
There are numerous types of animal cells and each of them is designed to serve specific functions. However, some of the most common types of animal cells are as follows:
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Muscle Cells
Myocyte, Myosatellite cells, Tendon cells, Cardiac muscle cells
Animal cells need to adapt to a more active and non-sedentary lifestyle as animals acquire their food, hence, they do not possess any of the specialized cell organelles such as chloroplasts.
Brief on Plant Cell
A plant cell is mainly a eukaryotic cell with a true nucleus and organelles similar to an animal cell but also consists of certain specific components such as chloroplasts which carry out photosynthesis. Plants are multicellular and have a distinct rigid wall surrounding the cells.
Plant Cell Functions
The plant cells are the building blocks of the plants. Since photosynthesis (the process of preparing food by the plants, by utilizing sunlight, carbon dioxide and water) is the major function performed by the plant cells it occurs in the chloroplasts of the plant cell.
Plant Cell Types
There are different types of plant cells some of which include the following different types:
These cells are hard or rigid and play a primary role in providing support to the plants if there is restraining growth due to the lack of hardening agents in the primary walls.
These are more rigid as compared to the collenchyma cells and it is because of the presence of a hardening agent. They are usually found in all the plant roots and are mainly involved in providing support to the plants.
The Parenchyma cells have a significant role to play in all plants. As they are the living cells of plants, which are involved in the production of leaves, they are also involved in the exchange of gasses, production of food, storage of organic products and cell metabolism. The Parenchyma cells are typically more flexible because they are thinner than other cells.
The Xylem cells are the transport cells in vascular plants. They are responsible for the transport of water and minerals from the roots to the leaves and other parts of the plants.
These are the common type of cells and the most heard ones, the phloem cells are the transport cells in vascular plants as they are responsible for transporting food which is prepared by the leaves to different parts of the plants.
Brief on Bacterial Cell
A bacterial cell is a prokaryotic cell that lacks a well-defined nucleus and membrane-bound organelles. Instead, it contains an irregular-shaped region where the genetic material is suspended. Bacteria is a single-celled organism.
Functions of a Bacterial Cell
The Cytoplasm or protoplasm is the part of the bacterial cells, where the functions for cell growth, metabolism, and replication are carried out. This is a gel-like matrix that is composed of water, enzymes, nutrients, wastes, and gasses and contains cell structures such as ribosomes, a chromosome, and plasmids.
Types of Bacteria Cells
The Bacterial cells are classified into five groups according to their basic shapes:
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Spherical (cocci)
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Rod (bacilli)
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Spiral (spirilla)
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Comma (vibrios)
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Corkscrew (spirochaetes)
These can exist as single cells, in pairs, chains or clusters.
Difference Between Plant, Animal and Bacterial Cell
|
Characteristic |
Animal Cell |
Plant Cell |
Bacterial Cell |
|
Size |
Animal cells are generally small in size when compared to the plant cell, on average they are 10 – 20 μm (micrometers) in diameter. |
Plant cells are large. The average size of a plant cell is 10 – 100 μm in diameter |
The bacterial cell is very small. It is about 0.5 – 5.0 μm in diameter almost about one-tenth the size of a eukaryotic cell. |
|
Type |
Eukaryotic cell |
Eukaryotic cell |
Prokaryotic cell |
|
Shape |
Animal cells vary in shape and are generally irregular due to the lack of a cell wall. They can be flat, round, oval, rectangular, concave, rod-shaped, or spherical and are mostly defined by the function they perform. |
Plant cells are similar and typically rectangular or cube-shaped. |
Bacterial cells are of different shapes such as spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) and corkscrew (spirochaetes). |
|
Cell Wall |
Animal cells lack cell walls but the cell membrane protects the cell from external damage and also plays a major role in selective permeability for the |
Plant cells have rigid cell walls that surround the plasma membrane. It provides tensile strength and protection against mechanical and osmotic stress. Plant cell walls are made up of pectic polysaccharides, proteins, cellulose, phenolic compounds, and water. |
Bacterial cells have a cell wall surrounding the inner components of the cell. Apart from providing strength to the cell, it also helps in maintaining the cell shape. Bacterial cell walls are made of peptidoglycan(murein). |
|
Nucleus |
The animal cell has a well-defined nucleus and comprises genetic material. It also controls the activities of the cell by regulating gene expression, hence known as the control center of the cell. |
The plant cell has a well-defined nucleus that stores the genetic material and also coordinates the cell’s activities such as cell division, metabolism, growth, and protein synthesis. |
Bacterial cells lack membrane-bound nuclei. The genetic material lies suspended in the cytoplasm. |
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vacuoles |
Animal cells generally have smaller vacuoles which sequester waste products. |
Plant cells have larger vacuoles that help maintain water balance. |
Bacterial cells have larger vacuoles and help to store ions and maintain water balance. |
|
Ribosomes |
Large 80S ribosomes |
Large 80S ribosomes |
Small 70s ribosomes. |
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Lysosomes |
Animal cells have many lysosomes that contain digestive enzymes to break down the molecules and protect them from foreign bodies. |
Lysosomes are small and less in plant cells and are not needed as they have a rigid cell wall that protects from foreign bodies that lysosomes digest. |
A lysosome is absent in bacterial cells. . |
|
Mitochondria |
Present |
Present |
Absent |
|
Centrioles |
Animal cells have centrioles located in the cytoplasm near the nucleus. They are made of microtubules and their major function is to assist the cell division process. |
Centrioles are absent in plant cells. |
Centrioles are not present in bacterial cells. |
|
Golgi apparatus |
Animal cells have larger and fewer Golgi bodies. |
Plant cells have small and larger numbers of Golgi bodies. |
There are no Golgi bodies in bacteria. |
|
Method of nutrition |
Animals cannot produce their food from simple inorganic substances like carbon-di-oxide and water and depend on other organisms for food. Hence they are called heterotrophs. |
Plants make their food in the presence of sunlight and hence are called autotrophs. |
Bacteria can obtain energy from the decomposition of dead organisms or by performing photosynthesis. They are both heterotrophs and autotrophs. |
|
Plastids |
Absent |
Present in plant cells, they give pigmentation color and also facilitate the trapping of sunlight for photosynthesis. |
Absent. |
Conclusion
Having a brief knowledge about different bacterial cells will certainly help you in learning deeper and understanding it.