In cell biology, one distinguishes between prokaryotic and eukaryotic cells. One type of eukaryotic cell and the functional basic unit of plants is the plant cell. There are a lot of important components within the plant cell, which fulfill diverse functions.
But before we come to that, please subscribe to the channel. It is for free but helps me a lot. With a monthly subscription you can also become a member of this channel now. Please use this form of support only if you have enough money to spend. One of the various distinct features of the plant cell is found around the cell itself.
The cell wall. This structure functions as a support skeleton and determines the shape of the cell. Further, the cell wall is a well-suited natural barrier against infections of fungi.
The cell wall is composed of cellulose embedded in a net with other complex polysaccharides and proteins. The plant cell wall is a strong structure that needs to be sufficient to withstand the high osmotic pressure that is present inside the cell. As for all eukaryotic cells, plant cells also possess a plasma membrane.
This structure out of lipids is selectively permeable. Certain molecules can pass through and others cannot enter or exit. The main function of the plasma membrane is to regulate nutrient and mineral transport. Inside the plasma membrane lies the cytoplasm.
Cytoplasm is described as the totality of both cytosol, a liquid containing the nutrients, the cytoskeleton and the organelles of a cell. Among these, the nucleus might be one of the most well-known cell compartments. The nucleus stores the majority of the genetic information, packed in DNA.
Within the nucleus, important processes take place. Replication to duplicate DNA and transcription to generate RNA. There is another structure located inside the nucleus, the nucleolus. One among the functions is the production and assembly of the important ribosomes, which will be mentioned again in a minute. The membrane of the nucleus is connected to a membrane of another cell organelle.
This is the so-called endoplasmic reticulum, abbreviated with ER. One distinguishes between the rough ER that has its granular structure because it is partly coated with ribosomes and there is the smooth ER. There are of course also free ribosomes in the cytoplasm.
At the rough ER protein synthesis but also protein modification and preparation for their transport take place. At the smooth ER proteins are also modified. In addition lipid synthesis occurs here.
The newly synthesized or modified proteins need to be transported to their point of destination. This is one of many functions that is overtaken by the Golgi apparatus. Here proteins that come from the rough ER are taken up.
The proteins are sorted, packaged and sent to their respective location. At the Golgi the proteins might also be modified further. Glycosylation for example might take place here.
The iconic plant cell wall also relies on the golgi. Polysaccharides are synthesized here. The secret of a leaf's green color lies in chlorophyll. This is found in an organelle named the chloroplast. Photothynthesis is a feature that makes plant cells so special.
Inside the chloroplasts is where the magic happens. Sunlight, water and carbon dioxide are used to produce energy in form of sugars and indirectly oxygen is produced. which may be the most important byproduct for us humans. Some plant cells also possess a different type of plastid. The amyloplast is responsible for the storage of starch, an important polysaccharide.
Mitochondria are the powerhouse of the cell. Sounds familiar, but why? These organelles provide the energy needed to power the cell's biochemical reactions. Peroxisomes are organelles that can accumulate and degrade peroxides that can be dangerous to other cell compartments. Hydrogen peroxide for instance is an unavoidable byproduct of biochemical reactions.
Plant cells have a gigantic permanent vacuole that can take up to 90% of the total cell volume in plants. This special organelle is water filled volume surrounded by a membrane known as the tonoplast. The vacuole has a whole bunch of different functions.
It maintains the internal pressure called turgor and contributes to the cell's total stability. It is also often seen as a large trash can that can digest waste inside the cell. Last but not least, one should mention the cytoskeleton.
In plants, the cytoskeleton is mainly composed of microtubules and actin filaments. The cytoskeleton contributes to the cell's shape and to the organization and movement of the organelles inside. This was a brief and simplified overview of a typical plant cell. If you are curious how an animal cell is structured, you may check out this video here. Please like the video if it was helpful to you and don't forget to subscribe to the channel.
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