Cell: Types and Functions

In this article, we will discuss some of the structures found in cells, as well as a few of the many different types of cells that can be found in the human body.

In some ways, cells can be thought of as miniaturised packages that contain miniaturised industries, warehouses, transportation networks, and power plants. These organisms are self-sufficient, generating their own energy and self-replicating – in fact, the cell is the smallest unit of life capable of replicating.

Cells, on the other hand, interact with one another and link in order to form a solid, well-glued-together creature. Cells produce tissues, which in turn form organs, and organs work together to maintain the life of the body.

Cells were discovered for the first time in 1665 by Robert Hook. He named them after the cella (Latin for “little apartment”) where monks used to live in monasteries, which is how he came up with the term.

Inside the cell

Distinct cell types can have drastically diverse appearances and perform drastically different functions within the body.

Examples include sperm cells looking like tadpoles, female egg cells looking round and nerve cells looking like thin tubes, among other things.

Despite their diversity, they frequently have certain structures in common; they are referred to as organelles in scientific terms (mini-organs). The following are some of the most significant:

The nucleus can be regarded as the nerve centre of the cell, and it is where everything happens. There is generally just one nucleus per cell, however this is not always the case; for example, skeletal muscle cells have two nuclei. The nucleus is where the majority of the cell’s DNA is located (a small amount is housed in the mitochondria). The nucleus communicates with the rest of the cell by sending out signals that instruct it to grow, divide, or die.

The nucleus is separated from the rest of the cell by a membrane known as the nuclear envelope; nuclear pores within the membrane allow for the passage of tiny molecules and ions, while larger molecules require the assistance of transport proteins to pass through the membrane.

The plasma membrane is a type of membrane that surrounds the blood vessels.

Each cell is surrounded by an unique membrane known as the plasma membrane, which serves to keep it separate from its neighbour. This membrane is mostly composed of phospholipids, which prevent water-based chemicals from entering the cell and causing it to rupture. The plasma membrane contains a variety of receptors that are responsible for a variety of functions, including the following:

Gatekeepers: Some receptors allow certain molecules to get through but prevent others from doing so.

Markers: These receptors serve as identification tags, notifying the immune system that they are a natural component of the organism rather than an invading foreign intruder.

Receptors that aid in communication: Some receptors aid in the cell’s communication with other cells and the surrounding environment.

Fasteners: Some receptors assist the cell in forming bonds with its neighbours.

Cytoplasm

The cytoplasm is the interior of the cell that surrounds the nucleus and is approximately 80 percent water; it contains the organelles as well as a jelly-like fluid known as the cytosol. The cytoplasm is composed primarily of water. The cytoplasm is the site of many of the most significant events that take place within the cell.

Lysosomes and peroxisomes are two types of organelles found in the body.

Both lysosomes and peroxisomes are essentially enzyme-filled storage compartments. These organelles contain enzymes that break down big molecules, such as old sections of the cell and foreign material, and transport them away. Peroxisomes contain enzymes that degrade harmful substances, such as peroxide, in the body.

Cytoskeleton

The cytoskeleton can be thought of as the structural framework of the cell. It aids in the preservation of its original shape. The cytoskeleton, on the other hand, is more flexible than conventional scaffolding; it is involved in cell division as well as cell motility, which refers to the ability of some cells to move, such as sperm cells, for example.

Through its involvement in the intake of material from outside the cell (endocytosis) and the movement of materials within the cell, the cytoskeleton also contributes to cell signalling and communication.

The endoplasmic reticulum 

The endoplasmic reticulum (ER) is a membrane-bound organelle that processes chemicals within the cell and aids in their transit to their final destinations. In particular, it is involved in the synthesis, folding, modification, and transport of proteins.

The endoplasmic reticulum (ER) is composed of elongated sacs, known as cisternae, which are kept together by the cytoskeleton. There are two types: rough ER and smooth ER. Rough ER is the more common type.

The Golgi apparatus

After molecules have been digested by the endoplasmic reticulum, they are transported to the Golgi apparatus. A cell’s Golgi apparatus is commonly referred to as the cell’s post office, because it is where objects are packaged and tagged. Once materials have been removed from the cell, they can either be employed within the cell or carried outside of the cell for use somewhere else.

Mitochondria

As the cell’s “powerhouse,” mitochondria are responsible for converting energy from our food into adenosine triphosphate, which can be used by the cell. Mitochondria are found in every cell of the body (ATP). However, mitochondria perform a variety of other functions, such as calcium storage and playing a part in cell death (apoptosis).

Ribosomes

DNA is translated into RNA (ribonucleic acid) in the nucleus, which is a molecule that is structurally similar to DNA and that conveys the same message. Ribosomes read the RNA and convert it into protein by assembling amino acids in the order specified by the RNA sequence.

Some ribosomes are free to move around in the cytoplasm, whereas others are connected to the endoplasmic reticulum.

Cell division is a process that occurs in the body.

Cell division continues throughout our entire lives.

Cells are continually being replaced in our bodies. It is necessary for cells to divide for a variety of reasons, including the growth of an organism and the filling of gaps left by dead or damaged cells following an injury, among others.

Mitosis and meiosis are the two types of cell division that take place.

Mitosis

Mitosis is the process through which the majority of cells in the body divide. The “parent” cell divides into two “daughter” cells as a result of this division.

The chromosomes of both daughter cells are identical to those of the parent and each other. These individuals are referred to as diploid due to the fact that they have two identical copies of their chromosomes.

Meiosis

Meiosis is responsible for the formation of sex cells, such as male sperm and female egg cells. Genetic recombination occurs during the process of meiosis when a little piece of each chromosome breaks off and attaches itself to another chromosome.

This means that each of the new cells has a distinct collection of genetic information, which makes them unique. It is this process that allows for the occurrence of genetic variety.

So, to summarise, mitosis aids in our growth, but meiosis ensures that we are all distinct from one another.

Types of Cells

The fact that there are hundreds of distinct types of cells in the human body is not surprising when you consider how complicated the human body is. The following are just a few examples of human cell types:

Stem cells are cells that can be regenerated.

Stem cells are cells that are in the process of deciding what they will become in the future. Some stem cells develop to become a specific cell type, while others divide to produce more stem cells in a given area. In both the embryo and some adult tissues, such as the bone marrow, they can be found in small amounts.

Bone cells are the cells that make up the bones.

It is believed that there are three main types of bone cells:

Osteoclasts are cells that break down bone.

Osteoblasts are the cells responsible for the formation of new bones.

Osteocytes are bone cells that are surrounded by bone and aid in the communication of other bone cells.

Blood Cells

There are three major types of blood cells: red blood cells, white blood cells, and platelets.

Red blood cells, which transport oxygen throughout the body; white blood cells, which are components of the immune system; and platelets, which aid in the formation of a blood clot to limit blood loss after an injury are all examples of blood cells.

Muscle cells are a type of cell.

Muscle cells, which are also known as myocytes, are long, tubular cells. In addition to movement and support, muscle cells perform a variety of interior activities, such as peristalsis, which is the flow of food through the digestive tract.

Sperm cells are a type of cell that reproduces.

Sperm are the tiniest sort of human cell that exists.

Cells with the shape of tadpoles make up the tiniest portion of the human body.

They are motile, which means that they have the ability to move. This movement is made possible by the use of their tail (flagellum), which is densely packed with energy-producing mitochondria.

Sperm cells are unable to divide, and they only have one copy of each chromosome (haploid), as opposed to the majority of cells, which contain two copies of each chromosome (diploid).

Cell of the female ovum

When compared to the sperm cell, the female egg cell is a colossal monster; it is the largest cell in the human body. The egg cell is also haploid, which allows the DNA from the sperm and the egg to join to form a diploid cell after fertilisation.

Fat cells are a type of cell that stores fat.

Adipocytes, commonly known as fat cells, are the primary constituent of adipose tissue and are found in large numbers in the body. They contain lipids that are stored in the form of triglycerides, which can be used as energy when required. When the triglycerides are depleted, the fat cells begin to shrink. Adipocytes are also responsible for the production of some hormones.

Nerve cells are a type of cell that is found in the nervous system.

Nerve cells serve as the body’s primary means of communication. They are also referred to as neurons, and they are composed of two basic components: the cell body and nerve processes. The nucleus and other organelles are located in the central body, while nerve processes (axons or dendrites) run like long fingers throughout the body, carrying signals throughout the body. Depending on the species, some of these axons can be more than one metre long.

Conclusion

We can finally conclude that cells are both fascinating and different in their functions and appearances. In one sense they are autonomous cities that function alone, producing their own energy and proteins; in another sense, they are part of the huge network of cells that creates tissues, organs, and us.