Question

Which among the following is not a true cell organalle
1. Ribosome
2. Lysosomes
3. Endoplasmic reticulum
4. Chloroplast

Answer 1

Correct Answer - Option 1 : Ribosome

Explanation:

• The correct option is ''Ribosome''
• Cell organelles are membrane-bound structure present inside the eukaryotic cells, that performs a specific function
• The ribosome is a membrane-less macromolecule consisting of DNA & Proteins.
• It is commonly referred to as a cell organelle in eukaryotic cells however, it is not a true cell organelle

​

• Ribosomes are the site for ''protein synthesis'' so they are also called the ''protein factory'' of the cell.
• There are two types of ribosomes

1. Eukaryotic ribosomes - 80s - occurs in the cytoplasm of eukaryotic cell
2. Prokaryotic ribosomes - 70s - occur in the cytoplasm as well as are associated with the cell membrane of prokaryotic cell

• Lysosomes: These are membrane-bound vesicular structures formed by the process of packaging in the Golgi apparatus.
• These are also called ''Suicidal bags'' because of their phagocytic activity. Lysosome keeps the cell clean by digesting any foreign material as well as worn-out cell organelles. 
• Endoplasmic reticulum: The network or reticulum of tiny tubular structures scattered in the cytoplasm is called the endoplasmic reticulum (ER).
• The ER divides the intracellular space into two distinct compartments, i.e., luminal (inside ER) and extraluminal (cytoplasm) compartments.
• The ER is of two types based on the presence or absence of ribosomes on its surface.
• The Endoplasmic reticulum bearing ribosomes on their surface is called Rough Endoplasmic Reticulum (RER) whereas in the absence of the ribosomes they appear smooth and are called Smooth Endoplasmic Reticulum (SER).
• Chloroplast is a double membrane-bound cell organelle.
• Out of the two membranes, the inner membrane is relatively less permeable. (the outer membrane contains porins).
• The space limited by the inner membrane is called the stroma.