Question

What do we mean by single cell protein?
A. One protein synthesized by muscle cell
B. Protein synthesized by microorganisms
C. Protein synthesized by skin cell
D. One protein synthesized by liver cell

Answer 1

Hint: Single cell proteins are proteins extracted from single celled or unicellular organisms. These proteins are consumed by humans as a substitute for protein in their diet. It can also be used in animal husbandry and has therapeutic and medicinal values.

Complete answer:
Single Cell proteins, abbreviated as SCP are proteins synthesized by unicellular microorganisms like algae, fungi, bacteria. The microorganisms are grown on agricultural or human wastes. These microorganisms are often photosynthetic or chemosynthetic and convert the carbon and nitrogen in the wastes into consumable proteins.
The advantages of using SCP as a protein source can be outlined as follows:
-The protein content in SCP is higher than vegetable grains.
-The microorganisms producing SCP can be used as a whole, while the roots, stems or leaves of plants are inedible.
-The microorganisms can be grown on inexpensive growth mediums like agricultural and human wastes.
-Climatic conditions/changes do not influence the growth of these microorganisms.
Agricultural crops require fertile soil, adequate water and temperature and use of fertilizers, pesticides, etc. The growth of SCP producing microorganisms does not require such conditions. They can be grown in areas with little water and infertile soils.
-The microorganisms can be genetically modified for obtaining the desired amount of proteins.

Typical disadvantages of using SCP as a dietary inclusion are – formation of kidney or gall bladder stones, the proteins can cause allergic reactions, nucleic acids in very high quantities can raise uric acid levels.
The proteins of muscle cells are actin and myosin.
Proteins of the skin cells are keratin, elastin and melanin.
Proteins secreted by the liver include albumins, C reactive protein, proteins required for blood coagulation.
Therefore, it can be concluded that the proteins synthesized by microorganisms are called Single Cell proteins or SCP.

Hence, the correct answer is option (B).

Note: Single cell proteins are secreted by microorganisms like bacteria, yeast, fungi, etc. Proteins extracted from these organisms are used as food for cattle, poultry and human beings. The SCP(s) are an inexpensive source of protein. The culture of SCP does not have a high water footprint and does not affect the environment negatively like industrial agriculture does.