The majority of eukaryotic cells can be found in the bodies of animals, plants, fungi, and protists. Bacteria and archaea, on the other hand, are made up of a single prokaryotic cell, as opposed to bacteria.
A cell membrane surrounds each and every cell in the body (also called a plasma membrane). In a cell, the cell membrane serves as a physical barrier that divides the inside of the cell from the outside of it. The plasma membrane is responsible for enclosing all of the cell’s components, which are suspended in a gel-like fluid known as the cytoplasm, within the cell. The organelles are found in the cytoplasm, which is their home.
When compared to prokaryotic cells, eukaryotic cells are distinguishable by the existence of a clearly defined nucleus in addition to other membrane-bound organelles such as the mitochondria, endoplasmic reticulum, and Golgi apparatus. Instead of having a distinct nucleus, prokaryotic cells have a portion of the cytoplasm known as the nucleotide, which is where the genetic material is contained. They are also devoid of organelles that are attached to membranes.
Animals are all multicellular, which means that a number of cells collaborate to produce the entirety of the creature. Especially in complex species such as humans, these cells can be highly specialised in order to fulfill a variety of distinct activities. As a result, despite the fact that they are all human cells, they frequently appear and function in completely different ways from one another.
Animal Cell Structure
Organelles, cytoplasmic structures, the cytosol, and the cell membrane are all components of a normal animal cell’s structure. In the cell, organelles are membrane-bound structures that have a variety of roles, each one distinct from the others. When cells perform particular actions in the cytoplasm, they form cytoplasmic structures, which are structures that are not surrounded by membranes but play an important role. The fluid component of the cytoplasm is known as the cytosol. It is the site of a wide range of biological functions, such as cell division, that take place.
Cell Membrane
An animal cell’s cell membrane is composed of a lipid bilayer with proteins buried within it. The structural arrangement of the cell membrane allows for the selective permeability of the cell membrane. Not all compounds will be able to pass through the cell’s defenses. A small number of non-polar molecules may be able to pass through relatively easily. Polar molecules, on the other hand, cannot, and as a result, transporters such as membrane proteins are required.
The cell membrane is the only structure that surrounds an animal cell and serves as its protective barrier. Animal cells lack a cell wall, but their cell membranes contain cholesterol, which helps to maintain the structural integrity and support of the cell in its environment. Aside from that, because animal cells do not have cell walls and consequently are fluid rather than rigid, they have the potential to move around because of the presence of cholesterol.
Nucleus
The nucleus is the most visible organelle in an animal cell, and it is also the most important organelle in the cell. This structure contains chromosomes, nucleolus, nuclear bodies, and nucleosomal RNA and DNA. An envelope around the cell (also known as the nucleus’ membrane) that is punctured by nuclear pores surrounds the cell. It is regarded as the control center of the cell since it holds the majority of an animal’s genetic material, and it is responsible for regulating the majority of the cell’s actions, including metabolism, growth, and reproductive ability. It accomplishes this by modulating gene expression.
Endoplasmic reticulum
The endoplasmic reticulum is a structure found in the body of cells.
The endoplasmic reticulum (ER) is a network of flattened sacs or tubules that are interconnected within the cell. The ER that contains ribosomes is referred to as rough ER, whilst those that do not contain ribosomes are referred to as smooth ER. In the case of rough ER, it is involved in protein synthesis, while smooth ER is involved in lipid synthesis.
Golgi apparatus
The Golgi apparatus is a type of organelle that is made up of stacks of cisternae that is found in the cytoplasm. When it comes to biomolecules, the Golgi apparatus is involved in the packing and secretion of biomolecules including proteins, glycosylation, and lipid transport. The Golgi complex is the phrase used to refer to the entire Golgi apparatus found within a cell as a grouping.
Mitochondria
The mitochondria are organelles that are semi-autonomous in the mammalian cell. They are endowed with their own genetic material (called mtDNA). The citric acid cycle is a process in which they are involved in the production of energy.
Lysosomes
Lysosomes are single-membrane structures that contain a variety of digesting enzymes, including pepsin. As a result, its primary role is digestion within the cell.
Endosomes
Endosomes are vesicles that are involved in the process of endocytosis. When an animal cell takes in a particle from the outside, it covers it with a membrane and transports it to the endosome where it is processed and eliminated. It is then transported to the lysosome via the endosome.
Vacuole
Animal cells have vacuoles, which are sac-like structures. They are, however, not as prominent in animal cells as they are in plant cells. In addition to osmoregulation and intracellular secretion and storage, vacuoles are also involved in excretion.
Centrioles
Centrioles are organelles that have a microtubular structure of 9+2 microtubules. They are capable of self-replication and contribute to the organisation of cell division. Animal cells are the only ones that contain them.
Cytoskeleton
The cytoskeleton is the structural framework that exists within an animal cell. Actin filaments, intermediate filaments, and microtubules are the three forms of cytoskeleton found in the body of a cell. Cell form, intracellular organisation, and cell motility are all controlled by these proteins, which serve as their primary function.
The movement of animals is aided by the presence of specific structures in their cells, such as flagella and cilia. A cell’s propulsion is accomplished by the use of flagella, which are long, slender whip-like projections. Flagella are employed for a variety of functions other than mobility, including feeling and signal transmission (e.g. in rod photoreceptor cells of the eye, olfactory receptor neurons of the nose, and kinocilium in the cochlea of the ear). Cilia are projections on the surface of certain cells that look like hairs. Animal cells with cilia include the epithelial cells of the lungs, which are an example of such a cell.
Animal Cells vs. Plant Cells
In that they are both eukaryotic cells and include organelles that are similar to those found in animal cells, animal cells and plant cells are similar. Animal cells are typically smaller in size than plant cells, however there are exceptions. Unlike animal cells, which come in a variety of sizes and forms, plant cells are more uniform in size and shape, and are often rectangular or cube shaped. In addition, plant cells possess features that are not found in animal cells. A cell wall, a big vacuole, and plastids are examples of such structures. Plastids, such as chloroplasts, assist the plant in storing and extracting the nutrients and other chemicals that it requires. Animal cells possess additional structures such as centrioles, lysosomes, cilia, and flagella that are not normally found in plant cells, such as centrioles, lysosomes, cilia, and flagella.
Conclusion
Plant and animal cells are vastly different from one another. The structure of a plant or animal cell is determined by how well it is able to sustain a steady internal environment (homeostasis). Plants and animals have evolved distinct methods of acquiring energy, and as a result, their cells are distinct. Animal cells are characteristic of the eukaryotic cell in that they are surrounded by a plasma membrane and include a nucleus and organelles that are attached to the membrane. Animal cells, in contrast to eukaryotic cells such as those found in plants and fungus, do not have a cell wall.
Each type of animal cell is specialised to perform a specific function. Blood cells are responsible for transporting oxygen to the body’s tissues and collecting carbon dioxide. They also transport hormones, enzymes, and vitamins to various locations throughout the body. Each type of animal cell is specialised to perform a specific function.