CHEM 210 Module 5 | Biochemistry Exam Q&A | Portage
Learning
These are original practice questions written for study. They cover common CHEM 210
Module 5 | Biochemistry topics: nucleotide structure and metabolism, purine and
pyrimidine synthesis and degradation, DNA replication, RNA transcription, protein
synthesis, the genetic code, mutations, and related clinical applications.
Question 1:
A nucleotide consists of which three components?
A. Sugar, phosphate, nitrogenous base
B. Amino acid, phosphate, base
C. Glycerol, fatty acid, base
D. Sugar, amino acid, phosphate
Correct answer: A
Rationale: Nucleotides contain a pentose sugar, a phosphate group, and a nitrogenous
base.
Question 2:
Which sugar is found in DNA?
A. Ribose
B. Deoxyribose
C. Glucose
D. Fructose
Correct answer: B
Rationale: DNA contains deoxyribose; RNA contains ribose.
Question 3:
Which sugar is found in RNA?
A. Deoxyribose
B. Ribose
C. Glucose
D. Galactose
Correct answer: B
Rationale: RNA contains ribose.
,Question 4:
Which nitrogenous base is found in RNA but not DNA?
A. Thymine
B. Uracil
C. Guanine
D. Cytosine
Correct answer: B
Rationale: RNA uses uracil instead of thymine.
Question 5:
Which nitrogenous base is found in DNA but not RNA?
A. Uracil
B. Thymine
C. Adenine
D. Guanine
Correct answer: B
Rationale: DNA uses thymine; RNA uses uracil.
Question 6:
Which bases are purines?
A. Adenine and guanine
B. Cytosine and thymine
C. Adenine and thymine
D. Guanine and cytosine
Correct answer: A
Rationale: Purines are adenine and guanine (two-ring structures).
Question 7:
Which bases are pyrimidines?
A. Adenine and guanine
B. Cytosine, thymine, and uracil
C. Adenine and thymine
D. Guanine and cytosine
Correct answer: B
Rationale: Pyrimidines are cytosine, thymine, and uracil (single-ring structures).
, Question 8:
In DNA, adenine pairs with:
A. Guanine
B. Thymine
C. Cytosine
D. Uracil
Correct answer: B
Rationale: Adenine pairs with thymine via two hydrogen bonds.
Question 9:
In DNA, guanine pairs with:
A. Adenine
B. Thymine
C. Cytosine
D. Uracil
Correct answer: C
Rationale: Guanine pairs with cytosine via three hydrogen bonds.
Question 10:
In RNA, adenine pairs with:
A. Thymine
B. Uracil
C. Guanine
D. Cytosine
Correct answer: B
Rationale: RNA adenine pairs with uracil.
Question 11:
De novo purine synthesis begins with which molecule?
A. PRPP
B. UMP
C. Orotate
D. Carbamoyl phosphate
Correct answer: A
Rationale: Purine synthesis starts with PRPP (phosphoribosyl pyrophosphate).
Learning
These are original practice questions written for study. They cover common CHEM 210
Module 5 | Biochemistry topics: nucleotide structure and metabolism, purine and
pyrimidine synthesis and degradation, DNA replication, RNA transcription, protein
synthesis, the genetic code, mutations, and related clinical applications.
Question 1:
A nucleotide consists of which three components?
A. Sugar, phosphate, nitrogenous base
B. Amino acid, phosphate, base
C. Glycerol, fatty acid, base
D. Sugar, amino acid, phosphate
Correct answer: A
Rationale: Nucleotides contain a pentose sugar, a phosphate group, and a nitrogenous
base.
Question 2:
Which sugar is found in DNA?
A. Ribose
B. Deoxyribose
C. Glucose
D. Fructose
Correct answer: B
Rationale: DNA contains deoxyribose; RNA contains ribose.
Question 3:
Which sugar is found in RNA?
A. Deoxyribose
B. Ribose
C. Glucose
D. Galactose
Correct answer: B
Rationale: RNA contains ribose.
,Question 4:
Which nitrogenous base is found in RNA but not DNA?
A. Thymine
B. Uracil
C. Guanine
D. Cytosine
Correct answer: B
Rationale: RNA uses uracil instead of thymine.
Question 5:
Which nitrogenous base is found in DNA but not RNA?
A. Uracil
B. Thymine
C. Adenine
D. Guanine
Correct answer: B
Rationale: DNA uses thymine; RNA uses uracil.
Question 6:
Which bases are purines?
A. Adenine and guanine
B. Cytosine and thymine
C. Adenine and thymine
D. Guanine and cytosine
Correct answer: A
Rationale: Purines are adenine and guanine (two-ring structures).
Question 7:
Which bases are pyrimidines?
A. Adenine and guanine
B. Cytosine, thymine, and uracil
C. Adenine and thymine
D. Guanine and cytosine
Correct answer: B
Rationale: Pyrimidines are cytosine, thymine, and uracil (single-ring structures).
, Question 8:
In DNA, adenine pairs with:
A. Guanine
B. Thymine
C. Cytosine
D. Uracil
Correct answer: B
Rationale: Adenine pairs with thymine via two hydrogen bonds.
Question 9:
In DNA, guanine pairs with:
A. Adenine
B. Thymine
C. Cytosine
D. Uracil
Correct answer: C
Rationale: Guanine pairs with cytosine via three hydrogen bonds.
Question 10:
In RNA, adenine pairs with:
A. Thymine
B. Uracil
C. Guanine
D. Cytosine
Correct answer: B
Rationale: RNA adenine pairs with uracil.
Question 11:
De novo purine synthesis begins with which molecule?
A. PRPP
B. UMP
C. Orotate
D. Carbamoyl phosphate
Correct answer: A
Rationale: Purine synthesis starts with PRPP (phosphoribosyl pyrophosphate).
