Answer:Cell Organelle

A small organ-like structure present inside the cell is called a cell organelle. It has a particular structural makeup and performs a specific function. Depending upon the presence or absence of membrane, cell organelles can be classified into three categories, namely:

Without membrane: Some cell organelles like ribosomes are not bounded by any membrane. They are present in prokaryotic as well as eukaryotic organisms.

Single membrane-bound: Some organelles are bounded by a single membrane. For example, vacuole, lysosome, Golgi Apparatus, Endoplasmic Reticulum etc. They are present only in a eukaryotic cell.

Double membrane-bound: Cell organelles like mitochondria and chloroplast are double membrane-bound organelles. They are present only in a eukaryotic cell.

Explanation:Structure and FUNCTIONS of Cells

Structure and functions of different cell inclusions are as follows-

Cell Organelle Occurrence/ Characteristic & Structure Function

Cell Membrane/ Plasma Membrane  

Present in both plant cell and animal cell.

Selectively Permeable: Allows the materials in and out of the cell according to the requirement of the cell.

Made up of bilipid layer and protein (Fluid Mosaic Model)

Encloses the contents of the cell.

Provides shape: animal cell.

Allows transport: by Diffusion and Osmosis.

Cell Wall  

Present only in a plant cell.

Hard and rigid.

Fully permeable.

Made up of Cellulose in plant and peptidoglycan in bacteria.

Protection

Gives shape and turgidity.

Cytoplasm  

Contains 80-90% water and many organic and inorganic compounds.

Colloidal, Viscous, Jelly like fluid inside the cell.

Contains ENZYMES responsible for all the metabolic activity taking place inside the cell.

Nucleus

(Director/ Brain of the Cell)

Covered by a double MEMBRANOUS nuclear membrane in a Eukaryotic Cell.

Contains DNA, RNA, Protein, nucleolus, and Chromatin network.

Controls the activity of the cell.

Starts cell division.

It has the chromosomes or DNA which controls the hereditary characters

Mitochondria (The Power House of The Cell / Storage Batteries)  

Double membranous structure.

Autonomous body as contains its own DNA.

Self-duplicates

The main seat of respiration.

Stores energy in the form of ATP molecules.

Golgi Bodies

(Shipping Department of Cell)

Discovered by Camillo Golgi in 1898.

Originates from RER.

Contains Sac like Cisternae and Vesicles.

Has two faces – cis face or receiving face and trans face or supplying face.

Modification, Packaging, and transport of materials

Synthesis of lysosomes, plasma membrane

Endoplasmic Reticulum

(Framework of Cell)

A network of membranes.

RER bears ribosomes and appears rough

SER does not have ribosomes

Forms the skeletal framework of the cell.

Transport of materials from one cell to other.

Provides a surface for the synthesis of material – PROTEINS in RER and LIPIDS in SER.

Formation of lysosomes, Golgi bodies and vacuoles

Membrane Biogenesis

Detoxification of harmful substances in the liver.

Vacuole  

Arise from ER and GB

Surrounded by tonoplast and filled with cell sap

Store cell sap which may be liquid or solid food, toxic byproduct.

Provide rigidity and turgidity to plant cell

Lysosomes (Suicidal bags of Cell, natural scavenger, cellular housekeeper)  

Membrane-bound organelles

Present in all animal cells and few plant cells

Tiny circular single membrane-bound structures filled with digestive enzymes

Intracellular digestion of food in unicellular organisms.

Ribosomes (Protein Factories)  

Without a membrane

Consist of two subunits – 60S and 40S in eukaryote both made up of RNA

Synthesis of Proteins

Plastids  

Double membrane-bound

Types-

Leucoplast –Colourless plastid;

Chromoplast –Coloured Plastid – blue, red, yellow

Chloroplast – Green plastid

Autonomous self-duplicating body

Chloroplast – Perform Photosynthesis – Helps in the release of oxygen

Chromoplast – impart colour to flowers which help in pollination

Leucoplast – Storage

Amyloplast –Store starch

Aleuroplast – Store Protein

Elaioplast – Store fat