All About Animal Cells

Animal Cell
Animal Cell Components.

colematt / iStock / Getty Images Plus 

Animal cells are eukaryotic cells or cells with a membrane-bound nucleus. Unlike prokaryotic cellsDNA in animal cells is housed within the nucleus. In addition to having a nucleus, animal cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for animal cells.

Key Takeaways

  • Animal cells are eukaryotic cells that have both a membrane-bound nucleus and other membrane-bound organelles. These organelles carry out specific functions that are needed for the normal functioning of the cell.
  • Plant and animal cells are similar in that they are both eukaryotic and have similar types of organelles. Plant cells tend to have more uniform sizes than animal cells.
  • Cell structure and organelle examples include: centrioles, the Golgi complex, microtubules, nucleopores, peroxisomes, and ribosomes.
  • Animals typically contain trillions of cells. Humans, for example, also have hundreds of different cell types. The shape, size and structure of cells go along with their specific function.

Animal Cells vs. Plant Cells

Illustration of an Eukaryotic Animal Cell
Eukaryotic Animal Cell Illustration.

Encyclopaedia Britannica / UIG / Getty Images

Animal cells and plant cells are similar in that they are both eukaryotic cells and have similar organelles. Animal cells are generally smaller than plant cells. While animal cells come in various sizes and tend to have irregular shapes, plant cells are more similar in size and are typically rectangular or cube shaped. A plant cell also contains structures not found in an animal cell. Some of these include a cell wall, a large vacuole, and plastids. Plastids, such as chloroplasts, assist in storing and harvesting needed substances for the plant. Animal cells also contain structures such as centrioles, lysosomes, cilia, and flagella that are not typically found in plant cells.

Organelles and Components of Animal Cells

Illustration of a typical animal cell with labeled organelles
Animal cell organelles.

Mediran / Wikimedia Commons / CC-BY-SA-3.0

The following are examples of structures and organelles that can be found in typical animal cells:

  • Cell (Plasma) Membrane - thin, semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents.
  • Centrioles - cylindrical structures that organize the assembly of microtubules during cell division.
  • Cilia and flagella - specialized groupings of microtubules that protrude from some cells and aid in cellular locomotion.
  • Cytoplasm - gel-like substance within the cell.
  • Cytoskeleton - a network of fibers throughout the cell's cytoplasm that gives the cell support and helps to maintain its shape.
  • Endoplasmic Reticulum - an extensive network of membranes composed of both regions with ribosomes (rough ER) and regions without ribosomes (smooth ER).
  • Golgi Complex - also called the Golgi apparatus, this structure is responsible for manufacturing, storing and shipping certain cellular products.
  • Lysosomes - sacs of enzymes that digest cellular macromolecules such as nucleic acids.
  • Microtubules - hollow rods that function primarily to help support and shape the cell.
  • Mitochondria - cell components that generate energy for the cell and are the sites of cellular respiration.
  • Nucleus - membrane-bound structure that contains the cell's hereditary information.
    • Nucleolus - structure within the nucleus that helps in the synthesis of ribosomes.
    • Nucleopore - a tiny hole in the nuclear membrane that allows nucleic acids and proteins to move into and out of the nucleus.
  • Peroxisomes - enzyme containing structures that help to detoxify alcohol, form bile acid, and break down fats.
  • Ribosomes - consisting of RNA and proteins, ribosomes are responsible for protein assembly.

Animal Cell Types

Cilia and mucous cells of oviduct (rat)
Cilia and mucous cells of rat oviduct.

Micro Discovery / Getty Images

In the hierarchical structure of life, cells are the simplest living units. Animal organisms can be composed of trillions of cells. In the human body, there are hundreds of different types of cells. These cells come in all shapes and sizes and their structure suits their function. For example, the body's nerve cells or neurons have a vastly different shape and function than red blood cells. Nerve cells transport electrical signals throughout the nervous system. They are elongated and thin, with projections that extend out to communicate with other nerve cells in order to conduct and transmit nerve impulses. The major role of red blood cells is to transport oxygen to body cells. Their small, flexible disc shape enables them to maneuver through tiny blood vessels to deliver oxygen to organs and tissues.

Sources

  • Reece, Jane B., and Neil A. Campbell. Campbell Biology. Benjamin Cummings, 2011.
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Bailey, Regina. "All About Animal Cells." ThoughtCo, Apr. 5, 2023, thoughtco.com/all-about-animal-cells-373379. Bailey, Regina. (2023, April 5). All About Animal Cells. Retrieved from https://www.thoughtco.com/all-about-animal-cells-373379 Bailey, Regina. "All About Animal Cells." ThoughtCo. https://www.thoughtco.com/all-about-animal-cells-373379 (accessed March 19, 2024).