Eukaryotic cells
A eukaryotic cell is any cell with a true nucleus and organelles. The nucleus contains the majority of the cell’s DNA and is the genetic hub of a eukaryotic cell.
Organelles are membrane bound structures found inside eukaryotic cells and they play a similar role to the organs in our bodies. Organelles perform certain roles to help the cell function more efficiently.
In contrast to eukaryotic cells, prokaryotic cells, which are found in bacteria and many other microorganisms, don’t have their DNA enclosed within a nucleus and don’t have any organelles
What organisms have eukaryotic cells?
Many different organisms around the world, big and small, are made from eukaryotic cells. Any living thing that is made from more than one cell is made with eukaryotic cells. This includes all animals, plants, seaweed and fungi.
Many microscopic organisms also have eukaryotic cells. Groups such as algae and amoebas have eukaryotic cells. All eukaryotic organisms that aren’t an animal, plant or fungus are often lumped together in a broad group of organisms called protists.
Examples and descriptions of organelles
There are a range of different organelles that each perform different roles within a cell to help the cell survive. Some are more common than others and some are only found in certain organisms. Chloroplasts, for example, are only found in plant cells and some algae.
Nucleus – contains and protects the majority of the cells genetic material. The genetic material controls the actions of a cell through the expression of genes. The nucleus is a defining feature of eukaryotic cells.
Mitochondria – site of respiration. Mitochondria convert energy from food into a form of energy that can be used by cells.
Chloroplasts – site of photosynthesis in plant cells and photosynthetic protists. Chloroplasts convert CO2 into glucose and produce oxygen as a byproduct.
Smooth endoplasmic reticulum – is involved in the production of fats and the breakdown of carbohydrates and other compounds.
Rough endoplasmic reticulum– is associated with many ribosomes which make it ‘rough’. The rough ER is involved in the process of building proteins.
Golgi body – modifies and transports proteins.
Vacuoles – used to store substances such as water, sugars and even waste products.
Lysosomes – break down compounds such as carbohydrates, proteins and fats. They are filled with enzymes and are the digestion centers of eukaryotic cells.
Other structures found in eukaryotic cells
Cell membrane – barrier that separates the cell from the surrounding environment. The cell membrane regulates what goes in and out of the cell and provides protection from the environment. Also known as the plasma membrane.
Cell wall – A protective layer found surrounding the cell membrane of plant, fungi and some protist cells. Cell walls can be tough and provide protection and structural support.
Cytoplasm – the cytoplasm is a gel-like substance found inside the membrane of all cells. The organelles and nucleus float in the cytoplasm of a cell.
Ribosomes – produce proteins. Ribosomes are not true organelles because they are not enclosed in a membrane. Ribosomes can also be found in prokaryotic cells.
Specialised eukaryotic cells
There are thousands of different types of eukaryotic cells. The increased organisation within eukaryotic cells has allowed evolution of specialised eukaryotic cells that perform specialised functions such as protection, movement, energy storage or reproduction.
In humans alone we have a huge range of different cell types, all of which are eukaryotic. For example, we have red blood cells, white blood cells, skin cells, muscle cells, fat cells or adipocytes, and bone cells.
Within each of those categories of cells there is a range of different cells that are super specialised for certain tasks. For example, different white blood cells include T cells, B cells, neutrophils, basophils, eosinophils and Natural Killer cells and each different type of cell plays a different role in the immune system.
Last edited: 9 March 2016
