A plant cell consists of three distinct components: (i) Cell wall (ii) Protoplasm, and (iii) Vacuole. The protoplasm is the living part of the cell. It is externally bounded by cell membrane or plasma membrane. The cytoplasm contains several cell organelles namely mitochondria, plastids, ribosomes, endoplasmic reticulum, lysosomes etc. (Fig. 2.1). (i) Cell wall: Cell wall is the non-living protective layer outside the plasma membrane in the plant cells, bacteria, fungi and algae. The ... Vacuoles: Often the largest organelle in a plant cell, bounded by a single membrane called tonoplast. Function: Vacuoles play a major role in autophagy, maintaining a balance between biogenesis (production) and degradation of many substances and cell structures. Labeled diagram of plant cell. The typical characteristics that define the plant cell include cellulose, hemicellulose and pectin, plastids which play a major role in photosynthesis and storage of starch, large vacuoles responsible for regulating the cell turgor pressure. The onion cell which is a typical plant cell, has a distinct cell wall as its outer boundary and just within it is the cell membrane. The cells of the human cheek have an outer membrane as the delimiting structure of the cell.
