Advertisements
Advertisements
Question
Which of the following are purine bases?
(i) Guanine
(ii) Adenine
(iii) Thymine
(iv) Uracil
Advertisements
Solution
(i) Guanine
(ii) Adenine
Explanation:
Purines consist of six-membered and five-membered nitrogen-containing ring fused together.
Guanine and adenine are purine bases whose structures are
Adenine (A)

Guanine (G)
While thymine and uracil are pyrimidine bases.
APPEARS IN
RELATED QUESTIONS
What is peptide linkage?
Differentiate between the following:
Fibrous proteins and Globular proteins
The protein responsible for blood clotting is ____________.
The helical structure of protein is stabilized by:
The correct statement for protein haemoglobin.
Which functional group participates in disulphide bond formation in proteins?
Which of the following statement is correct:
Proteins are found to have two different types of secondary structures viz. α-helix and β-pleated sheet structure. α-helix structure of protein is stabilised by:
Proteins can be classified into two types on the basis of their molecular shape i.e., fibrous proteins and globular proteins. Examples of globular proteins are:
(i) Insulin
(ii) Keratin
(iii) Albumin
(iv) Myosin
In fibrous proteins, polypeptide chains are held together by:
(i) van der Waals forces
(ii) disulphide linkage
(iii) electrostatic forces of attraction
(iv) hydrogen bonds
Protein found in a biological system with a unique three-dimensional structure and biological activity is called a native protein. When a protein in its native form, is subjected to a physical change like change in temperature or a chemical change like, change in pH, denaturation of protein takes place. Explain the cause.
Which moieties of nucleosides are involved in the formation of phosphodiester linkages present in dinucleotides? What does the word diester in the name of linkage indicate? Which acid is involved in the formation of this linkage?
Assertion: β-glycosidic linkage is present in maltose,

Reason: Maltose is composed of two glucose units in which C–1 of one glucose unit is linked to C–4 of another glucose unit.
Explain the terms primary and secondary structure of proteins. What is the difference between α-helix and β-pleated sheet structure of proteins?
The main structural feature of proteins is
Each polypeptide in a protein has amino acids linked with each other in a specific sequence. This sequence of amino acids is said to be ______.
Peptide linkage is:
Given below are two statements labelled as Assertion (A) and Reason (R).
Assertion (A): Proteins are found to have two different types of secondary structures viz alpha-helix and beta-pleated sheet structure.
Reason (R): The secondary structure of proteins is stabilized by hydrogen bonding.
Select the most appropriate answer from the options given below:
Out of the following, which type of interaction is responsible for the stabilisation of the α-helix structure of proteins?
Assertion (A): Proteins are polymers of α-amino acids connected by a peptide bond.
Reason (R): A tetrapeptide contains 4 amino acids linked by 4 peptide bonds.
