Question 1

Which of the following statements about the structure of proteins is true?

Accepted Answer

a) The sequence of amino acids in a protein represents the primary structure where one amino acid is attached to the other with the peptide bond.b) The helices of protein are not always left handed. In alpha helix protein, every backbone N&#8722;H group donates a hydrogen bond to the backbone C=O group of the amino acid located three or four residues earlier along the protein sequence so it is right-handed.c) Haemoglobin is an oligoprotein which has four polypeptide chain, two alpha chain, and two beta chain. It has a quaternary structure where each polypeptide has heme group with iron in the center. d) Proteins are heteropolymers containing strings of amino acids where the different amino acids are attached to each other by peptide bonds.So, the correct answer is option D.

Question 2

Which one is the most abundant protein in the animal world?

Accepted Answer

Correct option: CExplanation:The most abundant protein in the animal world is Collagen. It is found in the extracellular matrix of connective tissues like cartilage, bones, tendons, ligaments, and skin.Trypsin is an enzyme which hydrolyses proteins into smaller peptides in the small intestine. It is produced as the inactive zymogen trypsinogen in the pancreas.Haemoglobin is a iron-containing oxygen-transport protein found in red blood cells.Insulin is a peptide hormone produced by beta cells of the pancreatic islets in response to high level of blood glucose.Thus, Option C is correct.

Question 3

Transamination is

Accepted Answer

Transamination reaction is the transfer of amino groups from an amino acid to a keto acid. The enzyme is transaminase. It helps in formation of different amino acids which are not formed by reductive amination.So, the correct answer is option A.

Question 4

_____is the most abundant protein in animal world and ____is the most abundant protein in the whole biosphere.

Accepted Answer

Collagen is a protein which is most abundant in the animal world and is a connective tissue and rubisco is an enzyme which is the most abundant protein in the whole biosphere because rubisco is the enzyme which is responsible for the sugar formation during photosynthesis.So, the correct option is 'Collagen, RuBisCO'

Question 5

What are the functions of proteins?

Accepted Answer

Proteins are the most important nutrient in our food. Functions of proteins:(i) The major structural component of cells which is responsible for the building and repair of body tissues.(ii) Proteins do most of the work in cells and are required for the structure, function, and regulation of the body's tissues and organs.(iii) It helps our body to fight against infections.(iv) It helps in the formation of nails, hair and muscles.

Question 6

Name one element invariably found in proteins but not in all carbohydrates and lipids.

Accepted Answer

Proteins, carbohydrates and lipids are made from three basic molecules: carbon, hydrogen and oxygen. However, all proteins contain an element not found in carbohydrates and lipids is nitrogen. Nitrogen which is present in all amino acids (the building blocks that make up the protein chains).

Question 7

Which of the following elements are present in all proteins?1. Carbon2. Hydrogen3. Oxygen4. NitrogenSelect the correct answer from the codes given below.

Accepted Answer

Proteins are found in all living organisms and are composed of molecules called amino acids. Each amino &#10;acid contains four elements they are hydrogen, oxygen, nitrogen and carbon and in certain cases may also contain sulfur.

Question 8

The contractile protein of skeletal muscle involving ATPase activity is

Accepted Answer

The contractile protein of skeletal muscle involving ATPase activity is myosin. Myosins comprise a family of ATP-dependent motor proteins and are best known for their role in muscle contraction and their involvement in a wide range of other eukaryotic motility processes. They are responsible for actin-based motility. The term was originally used to describe a group of similar ATPases found in striated and smooth muscle cells.

Question 9

A peptide bond is found in which type of biological molecule

Accepted Answer

A peptide bond is found in proteins between two amino acids.A. Carbohydrates possess glycosidic linkages between two monosaccharides.B. Lipids possess ester bonds which are covalent in nature formed during condensation reactions.C. Nucleic acids possess phosphodiester bonds that is present between carbon atoms of adjacent sugar molecules in DNA and RNA. Hence, the correct answer is 'Protein'.

Question 10

Why are proteins considered to be heteropolymers?

Accepted Answer

A polymer is a giant molecule made up of many smaller molecules calledmonomers. If all the monomers are identical the polymer is a homopolymer.For example starch is made solely of glucose molecules so starch is a homopolymer. If the monomers are not identical the polymer is heteropolymer . Proteins are made up of up to 20 different amino acids, so proteins are heteropolymers.

Introduction to Proteins

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REVISE WITH CONCEPTS

Proteins

Basic Knowledge of Proteins

Proteins

QUICK SUMMARY WITH STORIES

Proteins - Introduction and classification

Polypeptides

Bio-polymers - Proteins-I

Structure of Proteins-II

Simple and Conjugated Proteins

Protein: Composition, Structure and Variety