Home
Class 11
BIOLOGY
" All enzymes are proteins " . This stat...

" All enzymes are proteins " . This statements is now modified because an apparent exception to the biological truth is

A

arylsulfatase

B

dehydrogenase

C

ribozyme

D

nitroreductase

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • BIOMOLECULES

    AAKASH SERIES|Exercise EXERCISE - I (Chemical reactions)|4 Videos

  • BIOMOLECULES

    AAKASH SERIES|Exercise EXERCISE - I (Properties & Nature of enzyme Action)|12 Videos

  • BIOMOLECULES

    AAKASH SERIES|Exercise EXERCISE - III (Previous AIPMT/NEET Questions) (Enzymes)|11 Videos

  • BIOLOGICAL CLASSIFICATION

    AAKASH SERIES|Exercise EXERCISE-III (Previous AIPMT/NEET Question)|37 Videos

  • CELL CYCLE AND CELL DIVISION

    AAKASH SERIES|Exercise Exercise-III|18 Videos

Similar Questions

Explore conceptually related problems

(A) All enzymes are proteins but all proteins are not enzymes. (R) Keratin is an enzyme.

According to widely accepted "fluid mosaic model" cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statement is incorrect?

All enzymes of TCA cycle are located in the mitochondria matrix except one, which is located in inner mitochondrial membranes in eukaryotes and in cytosol in prokaryotes. This enzyme is

Which of the following statements are correct ? I. P_(4) molecule is very reactive because of angular strain. II. The basicity of H_(3)PO_(3) is 3. III. In gas phase, all P-Cl bonds of PCl_(5) have same bond length. IV. In solid state, PCl_(5) exists as an ionic solid, in which anion [PCl_(6)]^(-) has octahedral and cation [PCl_(4)]^(+) has tetrahedral shape.

Read the following statements I) All hormone receptors are proteins II)All hormones are protein hormones III)The hormone fucntion is generally close to the site its release The incorrect statements are

All the following statements are correct, except

The chemical behaviour of dihydrogen is determined, to a large extent, by bond dissociation enthalpy. The H-H bond dissociation enthalpy is the highest for a single bond between two atoms of any element. What inferences would you draw from this fact? It is because of this factor that the dissociation of dihydrogen into its atoms is only 0.081% around 2000K which increases to 95.5% at 5000K. Also, it is relatively inert at room temperature due to the high H-H bond enthalpy. Thus the atomic hydrogen is produced at a high temperature in an electric arc or under ultraviolet radiations. Since its orbital is incomplete with Is' electronic configuration, it does combine with almost all the elements. Atomic hydrogen can accomplish reactions by I)losing the only electron to give H^+ II) gaining an electron to form H^- III) sharing electrons to form a single covalent bond The correct statement/s is/ are

alpha - amino acids are high melting crystalline solids because of the zwitterion structure. They are moderately soluble in water. In acidic medium, alpha - amino acids exist as cations (I) and thus migrate towards cathode under the influence of an electric field. On the other hand, in alkaline medium, alpha - amino acids exist as anions (III) and thus migrate towards anode under the influence of an electric field. However, at some intermediate value of p^(H) , the concentration of the cationic form (I) and anionic form (III) will become equal and consequently the alpha - amino acid will exist primarily as the neutral dipolar ion (II). At this p^(H) , there would be no net migration of the amino acid in an electric field. This p^(H) at which there is no net migration of the amino acid under the influence of an applied electric field is called isoelectric point (pI). Each amino acid has a characteristic isoelectric point. The pH of an amino acid that does not have an ionisable side chain such as alanine isd average of pK_(a) values of the carboxyl group and the protonated amino group. H_(3)overset(+)(N)-overset("R")overset("|")("C")H-COOH overset(" "OH^(-)" ")underset(" "H^(+)" ")hArr H_(3)overset(+)(N)-underset("Zwitterion (II)")(overset("R")overset("|")("C")H)-COO^(-)overset(" "OH^(-)" ")underset(" "H^(+)" ")hArr underset((III))(overset(+)(N)-overset("R")overset("|")("C")H)-COO^(-) Further, the alpha - carbon of all the amino acids (except glycine) is chiral (asymmetric) and hence amino acids can exist in teo stereoisomeric forms i.e., D and L. However, all the nautrally occurring amino acids belong to the L - series. underset("L(-)Glyceraldehyde")(HO-overset("CHO ")overset("| ")underset(" "CH_(2)OH)underset("| ")("C ")-H)" " underset("L-Amino acid")(H_(2)N-overset("COOH")overset("| ")underset("R ")underset("| ")("C ")-H) In alanine, carboxyl group ionises at pK_(a1)=2.34 and ammonium ion at pK_(a2)=9.69 . The isoelectric point of the amino acid is at p^(H) .

alpha - amino acids are high melting crystalline solids because of the zwitterion structure. They are moderately soluble in water. In acidic medium, alpha - amino acids exist as cations (I) and thus migrate towards cathode under the influence of an electric field. On the other hand, in alkaline medium, alpha - amino acids exist as anions (III) and thus migrate towards anode under the influence of an electric field. However, at some intermediate value of p^(H) , the concentration of the cationic form (I) and anionic form (III) will become equal and consequently the alpha - amino acid will exist primarily as the neutral dipolar ion (II). At this p^(H) , there would be no net migration of the amino acid in an electric field. This p^(H) at which there is no net migration of the amino acid under the influence of an applied electric field is called isoelectric point (pI). Each amino acid has a characteristic isoelectric point. The pH of an amino acid that does not have an ionisable side chain such as alanine isd average of pK_(a) values of the carboxyl group and the protonated amino group. H_(3)overset(+)(N)-overset("R")overset("|")("C")H-COOH overset(" "OH^(-)" ")underset(" "H^(+)" ")hArr H_(3)overset(+)(N)-underset("Zwitterion (II)")(overset("R")overset("|")("C")H)-COO^(-)overset(" "OH^(-)" ")underset(" "H^(+)" ")hArr underset((III))(overset(+)(N)-overset("R")overset("|")("C")H)-COO^(-) Further, the alpha - carbon of all the amino acids (except glycine) is chiral (asymmetric) and hence amino acids can exist in teo stereoisomeric forms i.e., D and L. However, all the nautrally occurring amino acids belong to the L - series. underset("L(-)Glyceraldehyde")(HO-overset("CHO ")overset("| ")underset(" "CH_(2)OH)underset("| ")("C ")-H)" " underset("L-Amino acid")(H_(2)N-overset("COOH")overset("| ")underset("R ")underset("| ")("C ")-H) N - terminus of the peptide structure is on the