Different nonliving Substance of Cytoplasm.

Ø  Plastid: Plastids are largest in size among the organelles present in cytoplasm. They can be seen clearly under microscope. Plastids are not present in Fungi, Bacteria and Animal cells. Plastids are mainly of two types: Leucoplast and Chromo plastid or Chloroplast. Leucoplastids are colorless and Chromo plastids are colored. Chromo plastid again is of two types Chloroplast and Chloroplast. 

Ø  Chloroplast: They possesses green pigments named chlorophyll in excess as a result they are green. Other pigments are also present to some extent. Every cell may contain one or more chloroplast. In higher plants the shapes of chloroplast is lenceolate. In Algal cells their shapes are of various types, e.g. cup shaped, spiral, reticulate, star shaped.semicircular etc.

Structure of chloroplast: The following parts make Chloroplast :1. A bi-layered semipermiable membrane surrounds the whole chloroplast. It is composed of protein and lipid. This is called lipoprotein.2. A hygroscopic matrix surrounded by a membrane is there. This matrix is called Struma.3. In the stroma, 40-80 well-arranged barrel shaped grana (sing: granum) are present. In one granum there are 5-25 granum disc. Insidethe granum disc, there are spaces. Probably chlorophyll and other.photosynthetic materials are present in this chamber.4. Some granum discs of two adjacent grana are connected by minute tubular bodies, which are called stroma lamelli.5. Many crystalline bodies are arranged in the membrane of grana disc. These are called quantosome. In the dark phase of photosynthesis, carbon-di-oxide is assimilated mainly in the quantosome. 

Ø  Mitochondria: Krebs cycle, fatty acid cycle, electron transport system etc.take place in mitochondria (sing: mitochondrion). All energy producing process occurs in mitochondria for which mitochondria are compared to the powerhouse of the cell. Number of mitochondria may vary according to the species. Normally each cell contains average 300-400 mitochondria. Their shape may be globular, rod, thread, star-shaped or ring-shaped. The outside of mitochondria is surrounded by a bi-layered membrane. The membrane is made by lipoprotein, which is enriched with lipid and protein. The outer membrane is smooth but the inner one has a series of enfolding into the inner cavity of mitochondria. These enfolding are called cristae. Small stalked granular bodies are arranged on the cristae and they are called auxisome. Various enzymes.

Ø  Endoplasmic reticulum:In a mature cell a network is found in the cytoplasm. This is called endoplasmic reticulum. Endoplasmic reticulum is of two types - smooth and rough. ER having ribosome on its body is called rough endoplasmic reticulum.

Structure: They are bounded by double-layered semipermiable membrane. Normally they are branched but may occur in parallel. They are continuous with the nuclear membrane and the cell membrane. Chemically the membrane is made by lipoprotein. Small granular bodies may be present on it.

Ø  Ribosome: Ribosomes are small spherical /granular organelle. They may occur freely in the cytoplasm and may be attached on the outer wall of endoplasmic reticulum.

Structure: These are spherical and bounded by double layered membrane. Mostly they are made by protein.

Ø  Golgi bodies/Golgi apparatus: Golgi bodies may be flat, spherical or elongated. Normally they are present near the nucleus. It was first observed by a scientist named Golgi in 1898 AD in the nerve cells of owl and cat. This organelle is afterward named Golgi apparatus after his name. In plant cells their number is small for which it is not always visible under microscope.

Structure: Golgi apparatus is tubular, small vesicle, vacuolar, elongated vessel like or lamillar bodies. They are vacuolar space bounded by double-layered membrane. necessary for respiration are well arranged in auxisome. About 70 types of enzymes and 14 types of co-enzymes are present in it. Matrix is also present inside the free space of mitochondria. The main function of mitochondria is to produce energy, like- respiration, oxidative phosphorilation, electron transport system etc.