WorksheetsBiochemistry Quiz No. 02
Total questions: 35
Worksheet time: 1hrs 10mins
The chirality of an amino acid results from the fact that its alpha carbon
Has no net charge
Is bonded to four different chemical groups
Is in the L absolute configuration in naturally occuring proteins
Is symmetric
Of the 20 standard amino acids, only ________________ is not optically active. The reason is that its side chain _____________.
Alanine; is a simple methyl group
Glycine; is a hydrogen atom
Glycine; is unbranched
Proline; has the secondary amino group
Two amino acids of the standard 20 contain sulfur atoms. They are:
Cysteine and serine
Cysteine and threonine
Methionine and cysteine
Threonine and serine
Amino acids are ampholytes because they can function as either a(an)
Acid or base
Neutral molecule or an ion
Polar or a nonpolar molecule
Standard or a nonstandard monomer in proteins
For amino acids with neutral R groups, at any pH below the pI of the amino acid, the population of amino acids in solution will have
A net negative charge
A net positive charge
No charged groups
Positive and negative charges in equal concentration
The formation of a peptide bond between two amino acids is an example of a(an)
Cleavage
Dehydration
Group transfer
Isomerization
The peptide alanylglutamyglycylananylleucine has
A disulfide bridge
Four peptide bonds
No free carboxyl group
Two free amino groups
An octapeptide composed of four repeating glycylalanyl units has
One free amino group on an alanyl residue
One free amino group on an alanyl residue and one free carboxyl group on a glycyl residue
One free amino group on a glycyl residue and one free carboxyl group on an alanyl residue
Two free amino and two free carboxyl groups
At the isoelectric pH of a tetrapeptide:
Net charge is positive
Net charge is negative
The total net charge is zero
There are four ionic charges
Prosthetic groups in the class of proteins known as glycoproteins are composed of
Carbohydrates
Lipids
Metals
Phosphates
The overall three dimensional structure of a polypeptide is called its
Secondary structure
Super secondary structure
Primary structure
Tertiary structure
Almost all naturally occuring proteins are the polymers of
L Alpha amino acids
D Alpha amino acids
L Beta amino acids
D beta amino acids
Primary structure of a protein has
Covalent bonds
Non covalent bonds
Covalent and non covalents
Covalent and hydrogen bonds
Which of the following properties of a protein is least likely to be affected by changes in pH
Tertiary structure
Primary structure
Secondary
Quaternary
Denaturation doesn't affect
Folding of polypeptides
Peptide bonds
Hydrogen bonds
Alpha helix and beta sheet structures
Out of these amino acids which one is exclusively ketogenic
Isoleucine
Leucine
Methionine
Tyrosine
Which of the following is NOT a fibrous protein?
Carbonic anhydrase
Collagen
Fibrinogen
Keratin
The general structure of all amino acids are same except for _______________
Lysine
Glycine
Proline
Alanine
Amino acid, which exists in two non-superimposable mirror images of eachother
Epimer
Anomer
Enantiomer
Chiral carbon
Which amino acid is essential, basic and has an Imidazole group?
Lysine
Arginine
Histidine
Glutamate
Secondary structure of a protein is stabilized by
Van der wall forcee
Hydrogen bonding
Covalent bond
Hydrophobic bond
How many amino acid residues are there in per turn of alpha helix?
3.5
4.6
3.0
2.5
Identify the amino acids containing nonpolar, aliphatic R groups
Phenylalanine, tyrosine and tryptophan
Glycine, alanine, leucine
Lysine, arginine, histidine
Serine, threonine, cysteine
Which among the following is a non essential amino acid?
Serine
Threonine
Lysine
Histidine
Which of the following is an essential amino acid?
Cysteine
Aspargine
Glutamine
Valine
Which of the following is an Imino acid?
Alanine
Glycine
Proline
Serine
Which among the following is both glucogenic and ketogenic?
Isoleucine
Leucine
Lysine
Histidine
Which of the following is most found in Proteins?
Carbon
Hydrogen
Oxygen
Nitrogen
Among these, ______________ is non polar.
Serine
Glutamate
Alanine
Arginine
Amino acid selenocysteine is coded by ______
UAA
UAG
UGA
AUG
Zwitter ion is _____________
Positively charged
Negatively charged
Polar
Containing boty negative and positive charges
Denaturation causes _____________
Decrease in viscosity
Decrease in surface tension
Increase solubility of proteins
Function disrupted
____________ is an essential aromatic amino acid.
Phenylalanine
Tyrosine
Methionine
Leucine
Enzyme released by small intestine is
Trypsin
Chemotrypsin
Aminopeptidase
Carboxypeptidase
_____________ out of these is covalent bond.
Hydrophobic
Ionic
Hydrogen
Disulphide
