Discover the 10 essential characteristics of cytoplasm, the jelly-like substance that fills every living cell. Learn about the composition, structure, and functions of cytoplasm, and how it supports the life of cells.
The cytoplasm is the internal environment of the cell. It is a colloidal system of gelatinous and heterogeneous consistency, composed of organelles and hialoplasma. It is located between the cytoplasmic membrane and the cell nucleus.
The cytoplasm comprises the entire volume of the cell except the nucleus of the same. At the time of its discovery it was thought that the cytoplasm was an aqueous bag that internally contained molecules and particles of different kinds and that acted freely in its interior. Subsequently it is understood that the cytoplasm is composed of several subtypes of delimited subcellular structures.
The function of the cytoplasm is to communicate the internal environment of the cell with the external one. Next, we expose its main characteristics.
Characteristics Of Cytoplasm
The discovery of cytoplasm can be attributed to the pioneering work of several scientists throughout history. In the 17th century, Antonie van Leeuwenhoek, a Dutch microscopist, was the first to observe living cells under a microscope. He noticed a “jelly-like” substance in the cells he examined, which is now known as cytoplasm.
Later on, in the 19th century, two German scientists, Matthias Schleiden and Theodor Schwann, proposed the Cell Theory, which states that all living organisms are composed of cells, and that cells are the basic unit of life. They also recognized the importance of cytoplasm in maintaining cell function and structure.
Further advancements in microscopy and cell biology in the 20th century allowed scientists to study cytoplasm in more detail, revealing its complex and dynamic nature. Today, cytoplasm is recognized as a crucial component of all living cells and plays a vital role in various cellular processes.
2. Origin of the word
The word “cytoplasm” comes from the Greek words “kytos,” meaning “container” or “cell,” and “plasma,” meaning “something molded or formed.” The term was first coined by the German anatomist and physiologist, Rudolf Virchow, in 1858.
At the time, there was a debate among scientists about whether the substance inside cells was a homogeneous fluid or a complex structure. Virchow proposed that it was a complex substance with various components, which he named “cytoplasm.” His idea was based on his observation of the different substances inside cells, such as organelles and other structures, which he believed made up the cytoplasm.
Since then, the term “cytoplasm” has become widely used in the field of cell biology to refer to the jelly-like substance that fills the space between the cell membrane and the nucleus, and which contains various organelles and other components that are essential for cellular processes.
3. Cytoplasmic matrix
The cytoplasmic matrix, also known as the cytosol, is the gel-like substance that fills the cytoplasm of a cell. It consists of a complex mixture of water, ions, organic molecules, and various types of proteins.
The cytoplasmic matrix is a dynamic environment where many essential cellular processes take place, such as metabolism, protein synthesis, and signaling. It also serves as a medium for the movement of molecules and organelles within the cell.
One of the key functions of the cytoplasmic matrix is to provide a structural support system for the cell. It contains a network of protein fibers called the cytoskeleton, which helps maintain the shape and integrity of the cell and assists in cell division.
In addition to providing structural support, the cytoplasmic matrix also plays a critical role in the regulation of gene expression. Many enzymes and regulatory proteins involved in gene expression are located within the cytoplasmic matrix, and their activity can be influenced by changes in the cytoplasmic environment.
Overall, the cytoplasmic matrix is a vital component of the cytoplasm, and its complex composition and functions are essential for the proper functioning of all living cells
4. Presence of the cytoplasm
Cytoplasm is a fundamental component of all living cells, and it is present in both prokaryotic and eukaryotic cells. In prokaryotes, such as bacteria, the cytoplasm is the entire contents of the cell, enclosed by the plasma membrane. It contains various organelles and molecules that perform essential cellular functions, such as DNA replication and protein synthesis.
In eukaryotic cells, which include animal, plant, and fungal cells, the cytoplasm is the fluid-like substance that fills the space between the plasma membrane and the nucleus. It is composed of a complex mixture of water, ions, organic molecules, and various types of proteins.
Within the cytoplasm of eukaryotic cells, there are also various organelles, such as mitochondria, ribosomes, and the endoplasmic reticulum, which are responsible for specific cellular functions. The cytoplasmic matrix also contains a network of protein fibers called the cytoskeleton, which helps maintain the shape and structure of the cell and is involved in cell division and movement.
Overall, the presence of cytoplasm is essential for the functioning of all living cells, and its complex composition and functions play a critical role in maintaining the integrity and survival of the cell
While the basic structure and functions of cytoplasm are similar across different types of cells, there can be some variations in its composition and properties depending on the cell type and the organism.
For example, in animal cells, the cytoplasm is a more viscous fluid compared to plant cells, which have a more fluid cytoplasm due to the presence of a large central vacuole. Additionally, animal cells have more prominent cytoskeletal elements, such as microfilaments, microtubules, and intermediate filaments, compared to plant cells.
In bacterial cells, the cytoplasm lacks many of the organelles present in eukaryotic cells, but it contains various enzymes and molecules involved in essential cellular functions, such as DNA replication and protein synthesis. The cytoplasm of bacterial cells also contains inclusion bodies, which are aggregates of molecules and can serve as storage sites for nutrients.
There can also be variations in the properties of the cytoplasm depending on the physiological state of the cell. For example, during cell division, the cytoplasm becomes more viscous to facilitate the movement of organelles and chromosomes. Similarly, under conditions of cellular stress, the cytoplasm can change its composition to respond to the stress and maintain the proper functioning of the cell.
Overall, while the basic properties and functions of cytoplasm are conserved across different types of cells, there can be variations in its composition and properties depending on the cell type, organism, and physiological state.
A membrane is a thin layer of material that separates two regions or compartments. In biology, membranes are essential components of cells and are responsible for maintaining the integrity and functionality of the cell.
The cell membrane, also known as the plasma membrane, is a selectively permeable membrane that surrounds the cell and separates the cytoplasm from the external environment. It is composed of a phospholipid bilayer, which consists of two layers of phospholipid molecules arranged with their hydrophilic (water-loving) heads facing outward and their hydrophobic (water-fearing) tails facing inward. The hydrophobic tails of the phospholipids create a barrier that prevents the movement of most substances across the membrane, while the hydrophilic heads allow the passage of certain molecules.
The cell membrane also contains various proteins, such as receptors and channels, that are involved in regulating the movement of molecules across the membrane and in cell signaling. Some membranes, such as those of organelles within the cell, may also contain specialized proteins and lipids that perform specific functions.
In addition to the cell membrane, there are also other types of membranes within cells, such as the nuclear membrane, which surrounds the nucleus and separates it from the cytoplasm, and the membranes of various organelles, such as the mitochondria and endoplasmic reticulum, which are involved in specific cellular functions.
Overall, membranes are essential components of cells, and their complex structure and composition allow for the regulation of cellular processes and the maintenance of cell integrity
7. Composition of the cytoplasm
It consists of two parts:
Citosol Colloidal matrix that supports the cellular organs. It forms the internal environment. It is made up of liquid and proteins.
Cytoskeleton It is a structure made up of protein filaments. Its function is to maintain the structure of the cell and facilitate its movement. Within the structure of the cytoskeleton, the filaments that compose it can be of different types:
Micro tubules Cylindrical hollow and rectilinear structures. They are made up of proteins called tubulin heterodimers. These proteins can be, in turn, alpha or beta, they are united to each other and they form to the tubular structure called micro tubule. There are some micro tubules that are stable (and are always within the cytoplasm and others that are not always present.) These are called temporary.
Actin filaments. It is a structure of less thickness. It is made up of chains. Each chain is known as actin monomer (protein).
Intermediate filaments They have an intermediate thickness, hence their name. It is the most heterogeneous of the 3. There are different types of intermediate filaments. Among the best known are keratins or neurofilaments.
8. Temperature action
Temperature can have a significant impact on the structure and function of cellular membranes. At low temperatures, membranes become more rigid, and their permeability to molecules can be reduced. This is due to the increase in the density of the membrane’s fatty acid tails, which pack more tightly together, reducing the fluidity of the membrane.
On the other hand, at high temperatures, membranes become more fluid and permeable, and their ability to perform their normal functions can be impaired. This is because the increased temperature causes the fatty acid tails to move more rapidly, making the membrane more flexible and unstable. In extreme cases, such as exposure to very high temperatures, the membrane can even melt, leading to the disruption of the cell.
Organisms have evolved various mechanisms to adapt to changes in temperature and maintain the stability and function of their cellular membranes. For example, some bacteria and other organisms produce fatty acids with shorter carbon chains or with double bonds, which can help maintain membrane fluidity at low temperatures. Some organisms also produce specialized proteins, such as chaperones, that can protect the membrane and other cellular components from damage caused by high temperatures.
Overall, temperature can have a significant impact on the structure and function of cellular membranes, and organisms have evolved various strategies to adapt to changes in temperature and maintain the integrity and function of their cells
9. What is the function of the cytoplasm?
The cytoplasm is a complex and dynamic part of the cell with many important functions. Here are some of the key functions of the cytoplasm:
- Supports the organelles: The cytoplasm provides a medium for the organelles to be suspended and to carry out their functions. It also helps to distribute the organelles throughout the cell and prevent them from coming into contact with one another.
- Metabolic reactions: Many metabolic reactions take place within the cytoplasm, such as glycolysis, the initial stage of cellular respiration, and the synthesis of various macromolecules, including proteins and lipids.
- Storage: The cytoplasm can act as a storage site for various molecules, including glycogen, lipids, and minerals.
- Cytoskeleton support: The cytoplasm contains a network of protein fibers known as the cytoskeleton, which helps to maintain cell shape, support the organelles, and enable cell movement and division.
- Transport: The cytoplasm is involved in intracellular transport, moving molecules and organelles within the cell. This is accomplished through the cytoskeleton and through various motor proteins that move along the cytoskeleton.
- Signal transduction: The cytoplasm is also involved in signaling processes within the cell. Signaling molecules can bind to receptors on the cell membrane, which then transmit the signal to the cytoplasm, where it can trigger a response.
Overall, the cytoplasm plays a vital role in the functioning of the cell, providing a medium for metabolic reactions, supporting organelles, and enabling intracellular transport and signaling processes.
10. Components of the cytoplasm
Within the cytoplasm there are different elements that fulfill diverse functions:
Cellular organelles: They are structures that have different functions within cells.
Water: 80% of the cytoplasm is water.
Mitochondria: Provides energy to the cell.
Golgi Apparatus: Sends the parts of the cell to the corresponding sector.