

MCQOPTIONS
This section includes 21 Mcqs, each offering curated multiple-choice questions to sharpen your UPSEE knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which of the following is NOT a part of the primary protein structure? |
A. | the amino acid sequence |
B. | the disulfide linkages |
C. | the planar nature of the amide linkage |
D. | the conformation of the polypeptide backbone |
Answer» E. | |
2. |
Which of the following amino acids is achiral? |
A. | alanine |
B. | glycine |
C. | serine |
D. | cysteine |
Answer» C. serine | |
3. |
A glycoside is the carbohydrate form of an |
A. | ether. |
B. | acetal. |
C. | aglycone. |
D. | alcohol. |
Answer» C. aglycone. | |
4. |
Which of the following compounds does NOT undergo mutarotation? |
A. | glucose |
B. | sucrose |
C. | ribose |
D. | fructose |
Answer» C. ribose | |
5. |
Which of the following statements regarding the biosynthesis of cholesterol is FALSE? |
A. | Cholesterol has the same carbon skeleton as its biosynthetic precursor, lanosterol. |
B. | Cholesterol is derived from the dimerization of farnesyl pyrophosphate in a headto-head manner. |
C. | Cyclization of squalene to cholesterol is initiated by acid-catalyzed ring opening of an epoxide. |
D. | Cholesterol has three fewer carbon atoms than lanosterol. |
Answer» B. Cholesterol is derived from the dimerization of farnesyl pyrophosphate in a headto-head manner. | |
6. |
Which of the following statements is NOT true regarding fatty acids? |
A. | Fatty acids dissolve in nonpolar solvents. |
B. | Triglycerides are esters of fatty acids |
C. | Most naturally occurring fatty acids have trans double bonds. |
D. | Fatty acids are biosynthesized from acetate. |
Answer» D. Fatty acids are biosynthesized from acetate. | |
7. |
Supply the correct words to complete this sentence: Electron-withdrawing groups such as nitro _________ the basicity of anilines, especially when substituted _______________. |
A. | increase ; ortho or para |
B. | increase ; meta |
C. | decrease ; ortho or para |
D. | decrease ; meta |
Answer» D. decrease ; meta | |
8. |
Predict which of the following compounds will have a lower boiling point than 1- butanal. |
A. | 1-butanol |
B. | 2-butanol |
C. | 1-butene |
D. | butanoic acid |
Answer» D. butanoic acid | |
9. |
Which of the following statements about organometallic compounds is FALSE? |
A. | Alkyllithium reagents (RLi) add to the carbonyl group of aldehydes and ketones. |
B. | Grignard reagents (RMgBr) add to the carbonyl group of aldehydes and ketones. |
C. | Alkyllithium and Grignard reagents do not add to esters. |
D. | Grignard reagents are prepared in ether or tetrahydrofuran (THF |
Answer» D. Grignard reagents are prepared in ether or tetrahydrofuran (THF | |
10. |
Which of the following compounds gives a secondary alcohol upon reaction with methylmagnesium bromide? Assume the usual acid workup. |
A. | butyl formate |
B. | 3-pentanone |
C. | pentanal |
D. | methyl butanoate |
Answer» D. methyl butanoate | |
11. |
The Williamson ether synthesis produces ethers by reacting an |
A. | alcohol with a metal. |
B. | alkoxide with a metal. |
C. | alkoxide with an alkyl halide. |
D. | alkyl halide with an aldehyde. |
Answer» D. alkyl halide with an aldehyde. | |
12. |
Which version of the radical halogenation of an alkane is MOST selective? |
A. | fluorination |
B. | chlorination |
C. | bromination |
D. | iodination |
Answer» D. iodination | |
13. |
Which of the following occurs during the initiation stage of a radical mechanism? |
A. | Nonradicals are formed from radicals. |
B. | Radicals are formed from other radicals. |
C. | Radicals are formed from nonradicals. |
D. | Nonradicals are formed from other nonradicals. |
Answer» D. Nonradicals are formed from other nonradicals. | |
14. |
Which of the following cycloalkanes has the MOST strain energy? |
A. | cyclobutane |
B. | cyclopentane |
C. | cyclohexane |
D. | cycloheptane |
Answer» B. cyclopentane | |
15. |
Which of the following cyclohexane conformations has the MOST energy (is the LEAST stable)? |
A. | chair |
B. | half-chair |
C. | boat |
D. | twist-boat |
Answer» C. boat | |
16. |
Which of the following may be separated by ordinary physical methods? |
A. | a pair of identical molecules |
B. | a pair of enantiomers |
C. | a pair of diastereomers |
D. | a pair of identical atoms |
Answer» D. a pair of identical atoms | |
17. |
When an external magnetic field is applied, what happens to the protons in a sample? |
A. | All protons align with the field. |
B. | All protons align opposite to the field. |
C. | Some protons align with the field and some align opposite to it. |
D. | All protons assume a random orientation |
Answer» D. All protons assume a random orientation | |
18. |
Which of the following physical properties differ for each of a pair of enantiomers? |
A. | solubility in ethanol |
B. | direction of rotation of plane-polarized light |
C. | boiling point and melting point |
D. | index of refraction |
Answer» C. boiling point and melting point | |
19. |
Which of the following statements about an sp hybridized carbon is FALSE? |
A. | It is divalent. |
B. | It forms bonds that are linear. |
C. | It has two p orbitals. |
D. | It always forms triple bonds to carbon. |
Answer» E. | |
20. |
Select incorrect statement: |
A. | Homolytic fission results in the formation of free radicals |
B. | Heterolytic fission results in the formation of Lewis acid and Lewis base |
C. | Completion of the octet provides a major driving force for the Lewis acid-base reaction |
D. | Steric bulky group increases nucleophilicity. |
Answer» E. | |
21. |
Select correct statement(s) about carbene: |
A. | It is obtained by photolysis of diazomethane or ketene |
B. | It can be inserted into alkene forming cycloalkane |
C. | It can exist as single or triplet |
D. | All the statements are true. |
Answer» E. | |