NEET MDS

The Power Course

Which of the following synthesize proteins that will remain in the cell as functional elements:



Choices

1 ) Rough endoplasmic reticulum
2 ) Free ribososmes
3 ) Smooth endoplsamic reticulum
4 ) Golgi complex

Explanation


Free ribosomes:

Ribosomes are highly complex structures made up of ribosomal RNA and specific protein. They are first observed under an electron microscope by George Emil palade in the mid-1950s. Ribosomes that are not attached endoplasmic reticulum or any other cell organelles are known as free ribosomes. These ribosomes act as a site for biological protein synthesis. Ribosomes consist of two parts or subunits known as:

i) Small ribosomal subunits that read mRNA and

ii) Large subunit that joins the amino acids to form large polypeptide chains. 

Cells with a large number of free ribosomes are basophilic as they produce the proteins that will remain in the cells.

Examples of cells with free ribosomes are:

Red blood cells (hemoglobin)

Developing muscle cells (contractile proteins like actin and myosin)

Nerve cells (neurofilaments) and

Keratinocytes of skin (keratin)

Note:

The ribosomes which are attached to endoplasmic reticulum called as rough endoplasmic reticulum synthesize the proteins for export from the cell.


Answer

Free ribososmes

Last Modified : 25-Dec-2019

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