Complete information on Ultra-structure of a typical plant cell

A typical plantcell contains the following metabolically active and metabolically inactive structures.

(1) Plasma membrane:

It is a living membr ane present below the cell wall. It is chemically composed of a biomolecular layer of lipid, which is interrupted by proteins. It is selectively permeable.

(2) Protoplasm:

It includes all partnership these of the cell. It is a living substance and is physical basis of life. The protoplasm of the nucleus is called nucleus is called nucleoplasma and between nucleus and plasma membrane is called cytoplasm.

(3) Plastids:

These are free organelles of the cell. They are of three types, such as leucoplasts, chloroplasts, chloroplasts and chromoplasts. Chloroplasts are green plastids. They are discoid containing chlorophyll and help in photosynthesis.

(4) Mitochondria:

These are rod-shaped spherical or filamentous organelles. Each mitochondrion consists of membrane and inner mass of matrix. The limiting membrane is two layered. The outer layer is smooth and the inner membrane is folded to form crystae. The knob-like structures called oxysomes are present in the inner face of inner membrane.

(5) Endoplasmic Reticulum:

It is a network of branched membrane-bound organelle of the cell. It is continous from nuclear membrane to plasma membrane and is distributed throughout the cell. It is of two types, such as rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). RER contains ribosomes on its surface.

(6) Golgi Bodies:

These are produced from the vesicles of RER. Tmembrane system forms the cup-like structure.

(7) Lysosomes

These are small sacs filled with digestive enzymes. These are bounded by a single membrane and the cavity contains densely granulated stroma and a large vacuole.

(8) Ribosmes:

These are smallest and most abundant cytoplasmic organelles distributed freely in cytoplasm or attached tot surface of ELECTRONS. These are non-membranous. Each ribosome has two subunits. They help in protein synthesis.

(9) Microbodies:

The microbodies like peroxysomes, glyoxysomes, and spherosomes are present in the cytoplasm.

(10) Nucleus:

All higher plants have single nucleus in their cells. Nucleus consists of nuclear membrane, nucleoplasm, chromatic and nucleolus.

(11) Endoplasmic Reticulum (RER) Acuole:

Few large vacuoles are present in cell. Vacuole is liquid filled cavity bounded by tonoplast.

(i) Cell wall- It is the exoskeleton of the cell secreted by protoplasm. Cell wall consists of middle lamella, primary wall, secondary wall and tertiary wall.

(ii) Besides these carbohydrates, fats, minerals, proteins, crystal are also present in the cytoplasm of different cell.