Plant Cell

Like all humans and animals, plants’ basic unit of life is also the plant cell. These cells with a true nucleus are eukaryotic and have numerous plant cell organelles. Each organelle in a plant cell has a specified function. Although animal and plant cells are pretty similar, the differentiating factor is the cell wall presence and the different functions of cell organelles in these cells. Also, plant cells have plastids, unlike animal cells. 

Rectangular in shape, the plant cells are larger in comparison to an animal cell. Some of the features that distinguish a plant cell from an animal include primary cell walls, plastids, large vacuole. 

Characteristics of the plant cell

1. Constructed outside the cell membrane, a plant cell consists of a cell wall made up of cellulose, hemicellulose, and pectin. The primary function of a cell wall is to provide shape to the plant cell to form tissues and organs. Intercellular communication is also controlled or regulated by these walls. 
2. A large central vacuole can be observed in numerous types of cells. These vacuoles are water-filled and get enclosed by tonoplast. Tonoplast is a membrane responsible for maintaining the cell’s turgor and controlling cytosol and sap movement. It also stores phosphorus and nitrogen. 
3. In the primary cell wall of a plant cell, a cell-to-cell communication pathway called plasmodesmata occurs. 
4. The plant cells contain plastids, and one of the most known plastids is chloroplasts.
5. Numerous cellular structures of the plant cell are membranous and contain lipids. 

The structure of a plant cell

Just like every other eukaryotic cell, the plant cell also has numerous plant cell organelles. 

• Cell wall

Outside the cell membrane is the rigid cell wall of a plant cell. Cellulose, hemicellulose, pectin, glycoproteins and lignin are the components of this cell wall. Proteins and polysaccharides are also present in the cell wall. Some of the fundamental functions of a cell wall are to support the cell, filter the molecules that move across the cell, and protect the cell against stress (mechanical).

• Cell membrane

The cell membrane of the plant cell is a membrane that is semi-permeable in nature and is composed of fats and proteins. It is responsible for regulating the movement of certain substances in and out of the cells. 

• Nucleus

Nucleus is one of the membrane-bound plant cell organelles that store genetic material or the DNA that is a must for cell division, growth, and metabolism. The nucleus of a plant cell consists of a nucleolus and a nucleopore. 

• Plastids

The membrane-bound plant cell organelles, Plastids possess their DNA. These cell organelles are significant for photosynthesis and storing starch. Some types of plastids are- Chloroplasts, leucoplast, chromoplasts. 

• Central vacuole

Around 30% of the plant cell that is mature is occupied by the central vacuole. It is surrounded by a membrane called tonoplast and is responsible for storage and sustaining turgor pressure. In addition, the cell sap, a fluid mixture of numerous substances including enzymes and salts, is present in the central vacuole. 

• Golgi Apparatus

The cell organelles of a plant cell that are responsible for the distribution of macromolecules that are synthesised to the different cell parts. 

• Ribosomes

The sites of protein synthesis, ribosomes are membrane-bound cell organelles that possess protein and RNA. 

• Lysosome

The suicidal bags of a cell, lysosomes contain digestive enzymes and are responsible for cellular waste disposal. They digest foreign bodies, food particles, and worn-out cell organelles. 

• Mitochondria

The powerhouse of the cell, Mitochondria, present in all eukaryotic cells is located in the cytoplasm. These are the double-membraned cell organelles that simplify the molecules of sugar and carbohydrate. They do so to produce energy for the cell. 

Types of plant cells

Mature plant cells specialise in certain functions. These specialised cells are sclerenchyma, parenchyma, phloem, collenchyma and xylem cells. 

• Collenchyma cells

Crucial for supplying support, these cells support the plant when a hardening agent is absent in primary walls and this results in restraining growth.

• Sclerenchyma cells

Sclerenchyma cells, the cells present in every plant’s roots,  have a hardening agent, making them more rigid than the collenchyma cells. Typically, they are involved in supporting the plants.

• Parenchyma cells

These living cells play a crucial  part in every plant as they play an important role for leaf production. These cells also participate in gases exchange, food production, organic products storage, and metabolism of cells. In addition, they are thinner than other cells, making them possess greater flexibility than the others. 

• Xylem cells

These cells in the vascular plants are responsible for transportation. The transportation cells, xylem cells  transport water and minerals from roots to all plant  parts. 

• Phloem cells

The other transport cell in the vascular plants is the phloem cells. These cells transport the food that the leaves produce to other plant parts. 

Conclusion

Like other living beings, the basic unit of life in plants is also the plant cell. Although a brief study would suggest that animals and plant cells are similar, there are significant differences. The plant cells are eukaryotic cells containing numerous membrane-bound organelles. Each plant cell organelle has a specified function to perform. When a plant matures, it consists of different types of cells that perform distinct vital functions.