Eukaryotic Cell and Animal Cell

Eukaryotic animal cells have a nucleus within a nucleus membrane and form a complex organism. The membrane-bound nucleus is also called the “true nucleus.” Organisms such as animals, plants, fungi, and protists are examples of eukaryotes because their cells are structured into compartmentalised structures known as organelles, such as the nucleus, which allows them to survive and reproduce in their environment.

A unique nucleus surrounded by inside membranes distinguishes eukaryotes from prokaryotes. These cells also contain other membrane-bound structures like mitochondria, endoplasmic reticulum, Golgi apparatus, and chloroplasts. 

Since the genetic material DNA is primarily found in the nucleus, this DNA is enclosed within the nuclear membrane and is not spread, unlike in prokaryotic cells, except for human RBCs (RBCs lose their nucleus during maturity for maximising its efficiency to take gases and plant sieve cells). All eukaryotic cells have a nucleus.

Features of Eukaryotic Animal Cell

• A membrane binds the nucleus, which has chromosomes (DNA material that contains genetic information).
• The cell contains mitochondria, the Golgi apparatus, endoplasmic reticulum, lysosomes, ribosome,chloroplast etc.
• Locomotory organs like flagella and cilia are present in eukaryotic cells. 
• Eukaryotic animal cells have a cytoskeletal structure, and cells are divided by mitosis.
• Eukaryotic animal cells do not have chloroplasts for photosynthetic purposes.

Functions of Various Eukaryotic Cell Organelles

Plasma Membrane: The plasma membrane is a semi-permeable membrane that acts as a cell’s barrier, protecting and dividing the cell from the outside environment.

Nucleus: It is a phospholipid bilayer that is double-layered, forming a wall. It serves as a repository for the cell’s genetic resources, stored in DNA, and all vital information required to function correctly. The production of ribosomes also occurs inside the nucleus.

Cytoskeleton: The cytoskeleton, which is found inside the cytoplasm and is composed of microfilaments, microtubules, and fibres, is responsible for providing the cell with its perfect shape, binding the organelles, helping in motility, and stimulating cell movement.

Nuclear Membrane: The cellular nucleus is surrounded by a double membrane layer responsible for controlling the flow of resources in and out of the cellular nucleus.

Nucleolus: The nucleolus is a non-membrane-bound organelle found inside the nucleus responsible for DNA replication.

Mitochondria: Mitochondria, also known as the powerhouse of cells, are the double membranous organelles inside the cell that are responsible for energy production. They serve as the cell’s primary source of energy. It is essential for the production of ATP and the conversion of glucose into ATP in the body. Mitochondria contain their own DNA and RNA so they can replicate themselves.

Endoplasmic reticulum: It is an organelle with a double membrane that divides the cell into pieces. It is connected to the cell’s nuclear membrane via a protein molecule. It is essential for protein synthesis, the creation of lipids and steroids, the storage and regulation of calcium, and the digestion of carbohydrate sources, among other things. The endoplasmic reticulum has two types: i) Smooth endoplasmic reticulum (SER) (smooth due to lack of ribosomes and RER synthesize lipids) ii) Rough endoplasmic reticulum (RER) (rough due to the presence of ribosomes and SER site for protein synthesis).

Ribosomes: The ribosome is located in the cytoplasm. They serve as the site for producing proteins in cells composed of ribosomal RNA and proteins.  eukaryotic  cells have 80S ribosomes.

Golgi bodies: The Golgi body is a compacted membrane that is primarily responsible for preserving the components produced by the cell. This membrane also aids in the storage and transportation of materials inside the cell. Therefore, it is also known as the post office in certain circles.

Lysosomes: Lysosomes, also known as suicidal bags, are membrane-bound organelles that contain digestive enzymes that break down macromolecules in the body. When foreign substances enter the cell, the lysosome plays a critical role in defending the cell by eliminating them. Many processes in the cytoplasm would be unable to perform at a low pH, demonstrating the need to compartmentalise the eukaryotic cell into organelles to operate effectively.

Cytoplasm: The cytoplasm is a sort of organelle found in the inner area and is jelly-like in appearance. It is critical for maintaining the stability of a cell and keeping the cell’s organelles separate from one another.

Cilia and Flagella: These are the external locomotory organelles on the surface of eukaryotic animal cells. Cilia and Flagella are responsible for cell rowing and up-down movement, respectively. Cilia in eukaryotic cells is different from a unicellular eukaryotic organism.

Types of Eukaryotic Animal Cell

Skin Cells: The cells from the tissues that protect us from the external environment. e.g., Melanocytes, keratinocytes, Merkel cells, etc.

Muscle cells: Long tabular-shaped cells help in the movement of the body. E.g., cardiac, skeletal, and smooth muscle cells.

Nerve cells: Cells found in the nervous system, also known as neurons. It includes Schwann and glial cells.

Blood cells: Cells are responsible for transporting gases (oxygen and carbon dioxide) from the lungs to other body parts and vice versa. It includes RBC, which has no nucleus, and WBC.

Fat cells: Also known as adipocytes, fat cells store lipids and fats.

Conclusion

Eukaryotic animal cells have a well-defined nucleus with a nuclear membrane. They have compartmentalized organelles with specific functions for every organelle.  Organisms such as animals, plants, fungi, and protists are examples of eukaryotes. A unique nucleus surrounded by inside membranes distinguishes eukaryotes from prokaryotes. One of its main functions is replication through meiosis and mitosis since it has a well-defined nucleus with DNA enclosed in it. These cells also contain other membrane-bound structures like mitochondria, endoplasmic reticulum, Golgi apparatus, and chloroplasts.