What is Protoplasm ?
Protoplasm refers to the living substance which makes up a cell. Biologists tend to speak about the cell nucleus and the cytoplasm
It is surrounded in plant cells by a cell wall. The entire cell of animal cells is made of protoplasm, surrounded by a cell membrane. In living organisms, the protoplasm consists of around 75–80 percent water
Hugo von Mohl first used the word "protoplasm" in 1846 to describe the substance in plant cells besides the cell wall, the cell nucleus and the vacuole
Protoplasm Definition
In general, the word protoplasm is used to refer to the living parts of a cell. However, the term protoplasm is not widely used these days, since it was originally used to indicate that a cell comprises only two elements, a nucleus and a plain, homogeneous cytoplasm.
We now realize the cytoplasm is very complex, and it contains complicated organelles. Nevertheless, we now refer to the protoplasm outside of the nucleus as the cytoplasm in eukaryotes, such as plants and animals, and the protoplasm inside the nucleus as nucleoplasm. In prokaryotes the content of a cell is called the cytoplasm collectively.
Structure of Protoplasm and its Components
Structural, it comprises 3 parts, like
1) Plasma/cell membrane
2) Cytoplasm
3) Nucleus
Component of Protoplasm
The major component of a protoplasm is the cytoplasm that exists in eukaryotes between the cell membrane and the nucleus. The cytoplasm is responsible for maintaining an environment which will allow the various organelles within it to perform their functions.
The nucleus is the second part to make up the protoplasm. It contains a cell, or organism's genetic material. It also has a role to play in controlling cell activity. In addition, the nucleus is the place where ribosomes are produced, which are essential for the creation of proteins in the cell.
Features of Protoplasm
The protoplasm is the living material of the cell. It is primarily composed of biomolecules like nucleic acids, proteins, lipids, and carbohydrates. It also holds inorganic salts and molecules of water. The protoplasm is surrounded by the membrane of the cells.
The protoplasm refers to the materials contained within the cell membrane, i.e. the prokaryotic cytoplasm, since prokaryotes do not have a distinct nucleus and other cytoplasmic organelles.
The protoplasm extends to the periplasm region between the cytoplasmic membrane and the outer membrane in certain prokaryotes, especially the Gram-negative bacteria.
This region contains a gel-like material called periplasm, which is a part of the Gram-negative bacteria protoplasm.
The protoplasm consists of two major divisions in eukaryotes: the cytoplasm, and the nucleoplasm (cell nucleus).
The cytoplasm is the eukaryotic cell's jelly-like material. Except for the nucleus it consists of the cytosol, the vesicles, the cytoskeleton, the inclusions and the organelles.
Thus, a eukaryotic cell's cytoplasm is that cell part between the cell membrane and the nuclear envelope. The material inside the nuclear envelope is known as nucleoplasm. Essential nucleoplasm is the nucleus protoplasm.
Functions of Protoplasm
It performs all the essential lifelong procedures. Its procedures include nutrients and oxygen, transforming food into living matter, ejecting used substances, renewing their worn parts and producing new cells themselves. All protoplasm functions are discussed in detail.
Reproduction
Cells divide to form identical daughter cells; the protoplasm nucleus function, e.g. the angiosperm meristematic region. A cell helps with the mitosis (in more evolved organisms) and meiosis processes in reproduction.
Irritability
The living protoplasm responds to stimuli, e.g. responds to light by retinal cells in the eye. It is the protoplasm's ability to respond to stimuli, and is an aspect of life itself that disappears with cell death.
Chemical
Most of these roles are performed within the cell, e.g. in mitochondrial respiration. Organisms need the energy required to perform various chemical reactions. The energy in plants comes from the photosynthesis process, while in the animals the energy comes from respiration.
Structure and Support
Some cells, such as collenchyma and sclerenchyma, are present to provide structural support, but all cells generally provide the structural basis of all organisms as well.
Excretion
Cells should get rid of excretory waste; they normally spread through the cell membrane out of the cell. It requires imbibing compounds that may be assimilated or otherwise used by the cells in metabolism. It is a process by which material is extruded by a cell. These materials may be useful (secretion) or useless (excretion) products, such as digestive enzymes and hormones, urine and sweat etc.
Transport
Cells produce the nutrients used in the chemical dissimilar procedure that takes place within them. A waste product is produced as a result of those processes. Then, cells work to get rid of that waste. In this way, the small molecules like oxygen, carbon dioxide, and ethanol pass by diffusion through the cell membrane. That method is called passive transportation. That method is called passive transportation. On the other hand, the larger molecules such as the proteins and polysaccharides enter and exit the cell via active transport.
Metabolism
A cell is responsible for metabolism which includes all the chemical reactions that occur within an organism to keep it alive.
Conductivity and Contraction:
It is the transmission of the excitation waves from the point of stimulation throughout the cell. This property is highly developed in nerve cells & in the muscle cells to a smaller extent. Contraction is a size change phenomenon, generally in the form of a shortening. It is highly muscular.
Growth
Growth means an increase in cell size which results in an increase in cytoplasm. Growth occurs on cell division; the protoplasm is consumed and the scale expanded. A cell's maximum size is largely limited by its surface area. Beyond the maximum size, the increase in a number of cells occurs when further growth of tissue is essential. This is done by cell division.
Conclusion
We have covered maximum information about Protoplasm that can help you to learn and educate.
FAQs on Protoplasm
1. What is protoplasm theory?
Purkinje came up with the term protoplasm while they observed plant cell sap. Max Schultze identified a similarity between protoplasm and sarcode which led him to propose a theory called Hertwig's theory of protoplasm. In this theory protoplasm is the physical basis of life.
2. What is the difference between protoplast and protoplasm?
Protoplasts are called naked cells, because they are not surrounded by plasmalemma bounded by any cell wall instead.
On the contrary, protoplasm is a translucent, semi-fluid present inside the cell that makes up the living matter of plants and animals alike.
It contains all the molecules of cellular matter such as proteins, fats and water.
3. What is the composition of protoplasm?
Protoplasm is made up of a mixture of small molecules like ions, amino acids, monosaccharides and water, and macromolecules like nucleic acids, proteins, lipids, and polysaccharides. The protoplasm surrounding the cell nucleus is known in eukaryotes as the cytoplasm, and the nucleoplasm within the nucleus.
4. Are protoplasm and cytoplasm the same?
The protoplasm and cytoplasm are not the same and have many differences. These are as follow:
Protoplasm is surrounded by a cell membrane from all of the sides but cytoplasm is the part that surrounds the nucleus in a cell.
Cytoplasm has organelles and other substances like enzymes, proteins but protoplasm is composed of the nucleus and the cytoplasm.
Cytoplasm consists of salt, water and protein whereas the protoplasm is composed of carbohydrates, nucleus and proteins.
Both of them differ in structure i.e. the cytoplasm doesn’t have a nucleus but protoplasm does.
5. Are the functions of protoplasm and cytoplasm different?
Yes, both cytoplasm and protoplasm have different functions. They are as follows:
Functions of the cytoplasm are given below:
The mitochondrion which is present in the cytoplasm helps in cellular respiration which is crucial for the survival of the organism.
Processes like glycolysis and cell division occur in the cytoplasm.
The cytoplasm acts as a protector of all the components that are present inside it and protects it from any damage.
The processes like protein synthesis and cellular respiration for breathing is supported by it.
Cytoplasmic streaming is a process which helps the movement of the constituents present in the cytoplasm.
The cytoplasm acts as the buffer which gives protection to the genetic material present in the cell.
Functions of the protoplasm are:
The protoplasm is said to provide shape to the organism.
It responds to stimulation.
It is important in the excretion of waste products.
6. What is the history of protoplasm and how was it discovered?
The protoplasm is defined as the ‘living part’ of the cell which constitutes many components of the cell like the cytoplasm and nucleus.
In 1868, Huxley defined the protoplasm as the ‘physical basis of life’ and scientist Felix Dujardin in 1835 described it as the homogenous mass of jelly-like substance and called it ‘Sarcode’. In 1839, scientist Purkinje coined the term protoplasm. Later, Von Mohl (1946) tried to show the role of protoplasm in cell division and other processes like metabolism. The similarities between the plant and animal protoplasm was discovered by scientist Max Schultz in 1861 who gave the ‘Protoplasm theory’ in which he stated that the protoplasm is the major part of the cell which has physiology roles. Learn more about Protoplasm at Vedantu Website and download the PDF format.
7. What is the physical nature of the protoplasm present in the cell?
The protoplasm in appearance is homogenous, colorless, jelly-like, transparent or semi-transparent and consists of 80-90% of water. It is granular in appearance and has many vacuoles. It responds to external stimuli like shock, cold, heat and chemicals. Salts, sugars and minerals are soluble in nature and are suspended in the protoplasm as molecules or ions. Apart from these, the protoplasm has substances like fats, proteins which are larger in size. This gives rise to a colloidal solution and the soluble constituents are called the colloids.
8. What is the streaming movement of cyclosis?
The circulation of protoplasm inside the cell is called the cyclosis or the cytoplasmic streaming and it is of two types:
The first one is rotation in which the protoplasm moves in one direction i.e. either clockwise or anticlockwise around the vacuoles of the cell. For example, the leaf cells of Vallisneria.
The second one is circulation in which the protoplasm moves in different directions around different vacuoles present inside the cell. For example, the stamina hairs of Tradescantia.
The absorption of water and its removal is mainly done by the contractility of the cytoplasm and all the particles of protoplasm are held together by weak forces like van der Waals forces.
