Las Eukaryotic cells are those cells that have a well-defined nucleus and organelles (also called organelles) covered by membranes.. These cells are typical of multicellular organisms such as animals, plants, fungi and algae with the exception of cyanobacteria. Eukaryotic cells are also unicellular organisms such as protozoa and amoebas. The characteristics of the eukaryotic cell make them very different from prokaryotic cells.
The structure of the eukaryotic cell is characterized by its multicompartmentality since it has different compartments in the form of organelles where the different functions of the cell take place.
The eukaryotic cell has a great complexity since a large number of metabolic processes take place inside it, such as cellular respiration, protein synthesis, carbohydrates, DNA duplication… that allow the cell to carry out functions such as obtaining energy and cell division, among others.
Their organization and functioning are complex and are the object of study in cell biology.
Eukaryotic cell structure
The eukaryotic cell has three parts well defined: cell membrane, nucleus and cytoplasm.
The cell membrane As already explained, it gives shape to the eukaryotic cell. Its function, in addition to shaping the cell, is also to regulate the exchange of substances with the outside. You can learn more in this post.
The cytoplasm It is the space between the plasma membrane and the nucleus and is where the nucleus, organelles (or organelles) and the cytoskeleton are located. In the cytoplasm is the cytosol, which is the substance that makes up the internal environment and where a large number of the metabolic processes of the cells take place.
The core It is the other major component of the cell that is explained below in the section on “Organelles of the eukaryotic cell.”
eukaryotic cell organelles
The eukaryotic cell in turn can be divided into animal and plant eukaryote. Both differ and you can find more information in this post.
Core
The main characteristic of the eukaryotic cell is that they have a nucleus. It is a membranous structure that surrounds the genetic material of the cell and protects it. The nuclear envelope is also called the caryotheca or nuclear membrane, which is different from the membrane that surrounds the outside of the cell.
The nucleus has an internal environment called the nucleoplasm that contains the chromosomes where the DNA is found and the nucleolus, which is a structure that helps in the synthesis of proteins.
Endoplasmic reticulum
Another important organelle of eukaryotic cells is the endoplasmic or endoplasmic reticulum. It is a network of channels and membranous sacs found in the cytoplasm and which in turn has two parts: the smooth and rough endoplasmic reticulum.
The smooth endoplasmic reticulum (SER) is the part where lipid synthesis occurs. The rough endoplasmic reticulum (RER) is where the protein synthesis. The rough part is due to the presence of ribosomes.
ribosomes
Ribosomes are the key organelles for the protein synthesis since they are the ones that are in charge of translating the messenger RNA into proteins. Its importance is vital.
Golgi apparatus
Another important organelle of eukaryotic cells is the Golgi apparatus, which is a series of membranous compartments that aid in the modification and transport of proteins and lipids to their final destinations from the endoplasmic reticulum. The Golgi apparatus also helps in the formation of lysosomes and in the synthesis of carbohydrates.
Lysosomes and peroxisomes
Lysosomes are organelles that come from the Golgi apparatus that contain enzymes that allow them to fulfill their function, which is to degrade substances that come from the external environment such as food, bacteria, viruses… or from the internal environment as degraded structures of the cell. Its function is the cell digestion.
mitochondria
Eukaryotic cells also have mitochondria. In this post we explain mitochondria in detail. are organelles that are the main source of energy production of the cell, we could say that they are the battery of the cell thanks to the oxidative phosphorylation that takes place in them. Mitochondria contain their own strand of DNA and their own translation machinery.
Chloroplasts
Chloroplasts are organelles that are only present in the plant cell and it is where the photosynthesis. They are similar to mitochondria and also contain their own strand of DNA and their own translation machinery.
cytoskeleton
Another important feature of eukaryotic cells is the presence of a cytoskeleton, a structure that helps maintain shape and structure of the cell and to facilitate cell movement and the organelles within the cell. The cytoskeleton is made up of microtubules and intermediate filaments and is key to cell division.
Cilia
Another important feature of eukaryotic cells is the presence of cilia. The cilia can fulfill different functions such as the displacement but also the uptake of substances or molecules as it happens in the porifera where the cilia direct the food in suspension towards the interior of the sponge.
flagella
The flagella are not present in all cells, they are filaments that are responsible for giving impulse to the cell so that it can move.
functions of the eukaryotic cell
Nutrition and obtaining energy
Inside eukaryotic cells, many metabolic processes are carried out, such as cellular respiration and photosynthesis, to obtain energy and produce molecules necessary for their survival.
Give structure and support
In both animals and plants, cells can be bone cells, muscle cells, or be part of stems, roots, or leaves to form the structures or skeletons of organisms.
reproduction and growth
The cell is responsible for duplicating DNA molecules for subsequent cell division that allows them to proliferate and divide to grow and reproduce. For this, it develops all the stages of mitosis and meiosis for this purpose.
Protection of genetic material
Cells develop mechanisms to protect DNA. These mechanisms can be metabolic processes such as DNA repair, the development of proteins such as chaperones that protect DNA against heat shock, or complex structures such as the nucleus.
Defense against external aggressions
There are cells whose function is to defend the body against infections and other aggressions, also macrophages and others are defensive structures to protect in the case of animals.
Control, coordination and response to changes in the external or internal environment
Cells also fulfill the function of responding to external stimuli and also of coordination, as is the case of neurons for motor coordination. Other forms of response to external or internal changes are those that are produced thanks to the cells that make up the organs of the endocrine system.
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