Question

One of the following is an example of storage protein.
A. Collagen
B. Keratin
C. Gliadin
D. Haemoglobin

Answer 1

Living organisms have reserves in their bodies which are used to reserve or store metal ions and amino acids. Storage proteins can be found in seeds of the plants, egg whites, and milk. These proteins are important because they help in plant development and plant survival.

Complete answer:
The meaning of each option needs to be considered in order to answer the question.
Collagen is a protein which is found abundantly in the bones, muscles, skin and tendons of the human body. It provides strength and structure to the body as it holds everything together. Fish, chicken and citrus fruits are the best sources of collagen. Collagen promotes skin health and heart. It is not a storage protein.
Keratin is a fibrous protein. It is generally found invertebrates in their hair, nails, feathers and claws. Salmon, sweet potatoes and mangoes are keratin rich foods which help in smoothening your hair and making them less frizzy. It is not a storage protein.
Gliadin is a combination of carbohydrates and proteins. Therefore it is also known as a glycoprotein. It may be found in grains, oats, barley and millet. It is a storage protein which has adverse effects on the health of a person.
Haemoglobin is a molecule of protein found in RBCs or red blood cells. It is made up of globulin chains which are four protein molecules connected together. It also contains iron and forms irreversible bond with the oxygen molecule. It is not a storage protein.

Therefore, the correct answer is option C.

Note:
Storage proteins as the name suggests, are glycoproteins which store carbohydrates and proteins. Due to their property of storing both proteins and carbohydrates, they are known as storage proteins. Other molecules mentioned, do not store anything else other than proteins. Thus, they are eliminated.