Download App

Biomolecules — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryBiomolecules1 Mark
MCQ
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: $\beta-$pleated sheet structure of protein shows maximum extension.
Reason: Intermolecular hydrogen bonding is present in them.
  • A
    Assertion and reason both are correct statements and reason is correct explanation for assertion.
  • ✓
    Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  • C
    Assertion is correct statement but reason is wrong statement.
  • D
    Assertion is wrong statement but reason is correct statement.
✓

Answer

Correct option: B.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
In $\beta-$pleated sheet structure, the polypeptide chains are held together by intermolecular $H-$bonds. Extension and contraction of $\beta-$pleated sheet structure of protein depends on the size of $R.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Biomolecules→Biomolecules — all question types→Chemistry STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion:Although $\mathrm{PF}_5, \mathrm{PCl}_5$ and $\mathrm{PBr}_5$ are known, the pentahalides of nitrogen have not been observed.
Reason: Phosphorus has lower electronegativity than nitrogen.
→

Read the passage given below and answer the following questions:
A tertiary alcohol H upon acid catalysed dehydration gives a product I. Ozonolysis of I leads to compounds J and K. Compound J upon reaction with KOH gives benzyl alcohol and a compound I, whereas K on reaction with KOH gives only M.

The following questions are multiple choice questions. Choose the most appropriate answer:
  1. Compound H is formed by the reaction of:
  1. The structure of compound I is:
  1. The structures of compound J, K and I, respectively, are:
  1. $\mathrm{PhCOCH}_3, \mathrm{PhCH}_2 \mathrm{COCH}_3$ and $\mathrm{PhCH}_2 \mathrm{COO}^{-} \mathrm{K}^{+}$
  2. $\mathrm{PhCHO}, \mathrm{PhCH}_2 \mathrm{CHO}$ and $\mathrm{PhCOO}^{-} \mathrm{K}^{+}$
  3. $\mathrm{PhCOCH}_3, \mathrm{PhCH}_2 \mathrm{CHO}$ and $\mathrm{CH}_3 \mathrm{COO}^{-} \mathrm{K}^{+}$
  4. $\mathrm{PhCHO}, \mathrm{PhCOCH}_3$ and $\mathrm{PhCOO}^{-} \mathrm{K}^{+}$
  1. When (J) is treated with acetic anhydride, in the presence of corresponding salt of an acid, the product obtained is:
  1. Cinnamic acid.
  2. Crotonic acid.
  3. Maleic acid.
  4. Benzylic acid.
  1. Which of the following statements is correct for compound (K)?
  1. It reacts with alkaline KMn04 followed by acidic hydrolysis and forms benzoic acid.
  2. It reacts with iodine and NaOH to form triiodomethane.
  3. It is prepared by the reaction of benzene with benzoyl chloride in presence of anhydrous aluminium chloride.
  4. It reacts with freshly prepared ammoniacal silver nitrate solution.
→
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Among nitrogen halides $NX_3,$ the dipole moment is highest for $NI_3$ and lowest for $NF_3.$
Reason: Nitrogen halides $NX_3,$ have trigonal pyramidal structure.
→
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Fructose reduces Fehling's solution and Tollens' reagent.
Reason: Fructose does not contain any aldehyde group.
→
Assertion $(A):$ Isopropyl chloride is less reactive than $\ce{CH_3Br}$ in $S_N2$ reactions.
Reason $(R): SN^2$ reactions are always accompanied by inversion of configuration.
→
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: $\ce{CH_3OCH_3}$ and $\ce{C_2H_5OH}$ has comparable molecular weight but boiling point of $\ce{C_2H_5OH}$ is more than dimethyl ether.
Reason: $\ce{C_2H_5OH}$ forms intermolecular $H-$bonding while $\ce{CH_3OCH_3}$ forms intramolecular $H-$bonding.
→
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Controlled nitration of aniline at low temperature mainly gives $m-$nitroaniline.
Reason: In acidic medium$, -NH_2$ group gets converted into $m-$directing group.
→
Assertion $(A): \ce{(CH_3)_3C-O-CH_3}$ gives $\ce{(CH_3)_3C-I}$ and $\ce{CH_3OH}$ on treatment with $HI.$
Reason $(R):$ The reaction occurs by $S_N1$ mechanism.
→
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: The electrical resistance of any object decreases with increase in its length.
Reason: The electrical resistance of any object decreases with increase in its area of cross-section.
→
Note: In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Competitive inhibitors compete with natural substrate for their attachment on the active sites of enzymes.
Reason: In competitive inhibition, inhibitor binds to the allosteric site of the enzyme.
→