EASY
Earn 100

A tetrapeptide has -COOH group on alanine. The produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolysis. For this tetrapeptide, the number of possible sequences (primary structures) with -NH2 group attached to a chiral centre is

50% studentsanswered this correctly

Important Questions on Biomolecules

EASY
What do you mean by Peptide linkage?
EASY
What is peptide linkages? How many peptide bonds are present in a tetra-peptide?
EASY
Define the following term, Peptide Bond.
EASY

 In alanylglycylleucylalanylvaline the number of peptide linkages is:

HARD
A tetrapeptide is made of naturally occurring alanine, serine, glycine and valine. If the C-terminal amino acid is alanine and the N-terminal amino acid is chiral, the number of possible sequences of the tetrapeptide is
HARD

How many of the given compounds will give a positive Biuret test____?

Glycine, Glycylalanine, Tripeptide, Biuret

EASY
What is peptide bond? Clarify peptide bond with an example of dipeptide.
EASY
Total number of tripeptides possible by mixing of valine and proline is ________ .
EASY
Which ONE of the following is likely to occur upon heating a solution of eukaryotic protein from 20°C to 95°C?
HARD
What is the probable free amino acid product formed when R1CHNH2CONHCHR2COOH reacts with 1 -fluoro-2,4-dinitrobenzene in presence of NaHCO3 followed by acid hydrolysis?
EASY
Which of the following molecules is eliminated during peptide bond formation?
EASY
Which of the following is the least likely to be involved in stabilizing the three-dimensional folding of most proteins?
MEDIUM

Following tetrapeptide can be represented as

Question Image

 

(F,L,D,Y,I,Q,P are one letter codes for amino acids)

HARD

Monomeric subunits of proteins can sometimes assemble into higher order assemblies. Two such related human proteins P and Qassemble into hexamers by sequential assembly of their subunits. However, while P assembles into a hexameric ring.Q assembles into a linear hexameric arrangement as shown in the figure. Only hexameric assemblies of the proteins are functional.

Question Image 

The equilibrium constants for association K1,K2,K3, and K4 of subunits at each step until pentamers are assembled, both for P and Q, are the same 105. However, the equilibrium association constant of the final step of assembly into a hexamer is drastically different, 1010 for P and 105 for Q. Based on this information, choose the statement(s) that is(are) likely to be true.

MEDIUM
A short peptide on complete hydrolysis produces 3 moles of glycine G, two moles of leucine L and two moles of valine V per mole of peptide. The number of peptide linkages in it are _____ .
MEDIUM
In an oligopeptide named Alanylglycylphenyl alanyl isoleucine, the number of sp2 hybridised carbons is _____.
EASY
Number of cyclic tripeptides formed with 2 amino acids A and B is:
EASY
A peptide synthesized by the reactions of one molecule each of Glycine, Leucine, Aspartic acid and Histidine will have _____ peptide linkages.
MEDIUM
In primary structure of protein, the protein thread showed helix with four amino acids S-C-Y-E and a naphthalene structure in amino acid Y. In such condition what will be the direction of helix and what are the positions of amino acids
EASY
In a protein molecule various amino acids are linked together by: