cell definition

The cell is the basic functional and functional unit of life. It is usually called the basic building blocks of life. There are two types of cells: eukaryotic cells, prokaryotic cells, and prokaryotes are organisms that consist of one cell, and they lack membrane-enclosed cellular organelles; Like the nucleus, and mitochondria, cells contain many types of organelles, and some of these organelles are single; Such as the nucleus, and the Golgi apparatus, and some others are available in large quantities, close to thousands and hundreds, such as mitochondria, peroxisomes, and lysosomes.[1]

animal cell components

A typical animal cell consists of the following main components:[2]

Cell membrane

The cell-plasma membrane is a thin, semi-permeable membrane that surrounds the cytoplasm and traps the contents of the cell inside.[2] It regulates the process of entering and leaving the cell, and this membrane consists of a bilayer of phospholipids, in addition to cholesterol molecules, and proteins that are divided into peripheral proteins and integrative proteins.[3]


The nucleus can be defined as a structure surrounded by a membrane that carries the genetic information of cells.[2] It is the command center of the cell, which is a large organelle that stores the cell’s DNA, and controls all activities of the cell; Such as growth and metabolism, using the genetic information of DNA.[4]

The nucleus contains a smaller structure known as the nucleolus, which houses ribonucleic acid (RNA), which helps transmit DNA commands to the rest of the cell and serves as a model for protein synthesis.[4] The nucleus membrane contains nucleopores, which are small holes in the nuclear envelope that allow proteins and nucleic acids to pass into and out of the nucleus.[2] The nucleus is surrounded by a double-stranded membrane, known as the nuclear envelope, which separates the chromatids from the cytoplasm.[1]


cytoplasm Where the cytoplasm consists of proteins, carbohydrates, salts, sugars, amino acids, and nucleotides, and it carries all the cellular organelles.[5]

cellular organelles

Organelles are specialized structures in the cell, which perform certain tasks, and are usually surrounded by a membrane of a bilayer of lipids, and both eukaryotic and prokaryotic cells have cell organelles, but the organelles in prokaryotic cells are more simple and not surrounded with a membrane,[1] Among the most important cell organelles are the following:[2]

  • Centrioles are cylindrical structures that organize the assembly of microtubules during cell division.[2] They are found only in animal cells, are located outside and near the cell nucleus, and they reproduce during interphase, before the initiation of mitosis (mitosis) and meiosis (meiosis) in the cell cycle.[6]
  • Cilia and flagella are specialized groups of microtubules that protrude from some cells and aid cellular locomotion.[2]
  • Cytoskeleton: It is a group of filaments and fibers that are found throughout the cytoplasm of a eukaryotic cell (containing a nucleus), and the cytoskeleton organizes the other components of the cell, maintains the shape of the cell, and is responsible for the movement of the cell itself And the movement of different organelles within it, and the very small filaments that make up the cytoskeleton were discovered due to the great analytical power of the electron microscope.[7]
  • The endoplasmic reticulum is a membranous organelle that shares part of its membrane with the membrane of the nucleus, and part of this reticulum is known as the rough endoplasmic reticulum, and it is fixed using ribosomes, and participates in the process of protein formation, and the rest of it is known as the endoplasmic reticulum soft, which contributes to the synthesis of vital lipids.[4]
  • Golgi network or Golgi apparatus: (in English: Golgi complex), which is the part responsible for the manufacture and storage of some cellular products,[2] They are flat and elongated bodies, stacked parallel to each other, surrounded by a single membrane, and are usually found near the nucleus, and their main function is to sort, encapsulate, manufacture and modify proteins, in addition to forming lysosomes and peroxisomes.[1]
  • Lysosomes or lysosomes are closed membrane organelles that contain a group of enzymes capable of degrading all types of biological polymers; Such as: proteins, nucleic acids, carbohydrates, and fats, and lysosomes act as the digestive system of the cell, which digests both the materials taken from outside the cell, and the old components in the cell itself. It is digested in the cell.[8]
  • Microtubules are hollow rods that help support and shape the cell.[2]
  • Mitochondria: The components of the cell that are responsible for generating energy.[2] They are cylindrical-shaped organelles, found in most eukaryotic cells, which are the sites of cellular respiration, which convert molecules such as glucose into energy molecules known as adenosine triphosphate (ATP), which powers cellular processes by breaking its high-energy chemical bonds. Mitochondria are larger in cells that require large amounts of energy to function; such as liver and muscle cells.[4]
  • Peroxisomes are enzymes that contain structures that help detoxify alcohol, form bile acids, and break down fats.[2] It is found in the cells of the liver and kidneys.[1]
  • Ribosomes: (in English: Ribosomes) are the protein factories of the cell, consisting of two subunits, and are either free-floating in the cytoplasm of the cell, or as an established part of the endoplasmic reticulum, using models and instructions provided by the two different types of RNA, ribosomes synthesize a variety of Proteins necessary for cell survival.[4]

the reviewer

  1. ^ a b c c “Organelles”, www.tutorvista.com, Retrieved 2-1-2018. Edited.
  2. ^ a b c d c h d th r z Regina Bailey (10-12-2017), “All About Animal Cells”, www.thoughtco.com, Retrieved 12-30-2017. Edited.
  3. ↑ Derrick Arrington, “Plasma Membrane of a Cell: Definition, Function & Structure”, www.study.com, Retrieved 30-12-2017. Edited.
  4. ^ a b c c Melissa Petruzzello, “6 Cell Organelles”, www.britannica.com, Retrieved 12-30-2017. Edited.
  5. ↑ “Cytoplasm”, www.tutorvista.com, Retrieved 30-12-2017. Edited.
  6. ↑ Regina Bailey (8-3-2017), “Centrioles”, www.thoughtco.com, Retrieved 1-2-2018. Edited.
  7. ↑ The Editors of Encyclopædia Britannica, “Cytoskeleton”, www.britannica.com, Retrieved 1-2-2018. Edited.
  8. ↑ “Lysosomes”, www.ncbi.nlm.nih.gov, Retrieved 1-2-2018. Edited.

What are the components of an animal cell?

writing – on the date : – Last updated: 2022-06-16 06:57:01