BCH 406 Biochemistry Final Exam Prep:
Comprehensive Questions and Answers for
2025/2026 Academic Year – Secure Your First-
Time Pass and Avoid Resits
pyrimidine synthesis are regulated by what? -
ANSWER//feedback inhibition what protects labile
intermediates, allows for coordination of multiple
enzyme activities, and maintains a high local
concentration of metabolites and enzymes with
tunnels? - ANSWER//substrate channeling what
things convert NMPs to NTPs? -
ANSWER//nucleotide diphosphate kinase (NDK)
and base-specific kinases what enzyme catalyzes
the reduction of the 2'-ribose carbon of NDPs using
a free radical dependent mechanism? -
ANSWER//RiboNucleotide Reductase which
enzyme converts all four NDPs? -
ANSWER//RoboNucleotide Reductase Name some
of the functions of nucleotides -
ANSWER//synthesis of purines and pyrimidines,
feedback inhibition, synthesis of dNDPs, enzyme
organization and substrate channeling what
balances the synthesis of dNTPs with sequential
binding of dNTPs in the specificity site> -
ANSWER//RNR what shapes the structure of the
catalytic site and determines which NDP binds to
the catalytic site? - ANSWER//Interactions between
dNTP bound in the specificity site and Loop 2 of
RNR What induces a structural rearrangement of a2
and B2 dimers? - ANSWER//dATP binding to the
activity Describe the 3 oligomerizeration states of
the a2 B2 complex - ANSWER//a. activity, catalytic,
,and selectivity sites are occupied a2 and B2 dimers
have weak affinity for each other b. formation of
a2B2 complex a2 dimer is loaded with substrates
and activators. B2 dimer docks and contributes an
electron to the a-active sites complex falls apart and
dNDP dissociates from a-active sites c. dATP binds
to activity site structural change in a-subunits B2
subunit docks differently forms inactive a4B4
octamer Starting from UMP, which 5 enzymes are
needed to synthesize dTMP? - ANSWER//a.
Rubonucleotide kinase (UMP kinase) b.
Ribonucleotide reductase (RNR) c. Nucleotide
diphosphate kinase (NDK) d. dUTP phosphatase
(dUTPase) e. thymidylate synthase Which enzyme
catalyzes the biosynthesis of dTMP from UMP? -
ANSWER//Thymidylate synthase nucleotide bases
are degraded to what? - ANSWER//uric acid or B-
alinine + NH4+ what can excess uric acid
production be treated with? - ANSWER//xanthine
oxidase inhibitors what are two diseases caused by
defects in the purine salvage pathways? -
ANSWER//gout, Lesch-Nyhan syndrome What
enzyme causes a metabolic domino effect whereby
purines are degraded to uric acid? -
ANSWER//adenosine deaminase Deficiency of
which enzyme can cause severe combined
immunodeficiency syndrome (SCID)? -
ANSWER//adenosine deaminase What type of cells
does chemotherapy target? - ANSWER//rapidly
proliferating cells what are some inhibitors of
glutamine amidotransferases? -
ANSWER//glutamine, azaserine, acivicin why is
thymidylate synthase a target for chemotherapy? -
,ANSWER//because it blocks production of dTTP,
which is lethal to rapidly dividing cells Anti-folates
inhibit thymidylate synthase. Name some. -
ANSWER//a. Methotrexate b. Pemetrexed c.
Proguanil d. Pyrimethamine e. Trimethoprim What
are the primary and secondary structures of the
DNA chain? How does the tertiary structure arise? -
ANSWER//primary: AGCT, secondary: double helix,
tertiary: arises in presence of water What are
driving forces that control double helix formation? -
ANSWER//the anti-parallel nature of the strands,
the base pairs Which nucleotides pair with each
other? - ANSWER//A/T, G/C What are the major
factors that control DNA hybridization? -
ANSWER//base pairing, hydrophilic and
hydrophobic interactions Why phosphorus? -
ANSWER//It's a common intermediate, good
leaving groups (has a "goldilocks" hydrolysis"),
stable in water What is telomerase and what does it
do? - ANSWER//An enzyme that adds a repeat
sequence to the 3' end of telomeres and uses its
own RNA to elongate telomeres. This reverses
telomere shortening. what is helicase and what
does it do? - ANSWER//it's an enzyme that moves
along nucleic acid strands and "unzips" them. This
prepares and allows for
transcription/translation/splicing, etc. what is
topoisomerase II and what does it do? -
ANSWER//it's an enzyme that cuts DNA strands to
manage DNA tangles and supercoils. This relieves
strain on the DNA helix what is dna polymerase? -
ANSWER//it's an enzyme that synthesizes DNA
from deoxyribonucleotides what is primase? -
, ANSWER//it's an enzyme that synthesizes short
RNA sequences that are primers. what is ligase? -
ANSWER//it's an enzyme that joins two sections of
DNA through hydrolysis what is a single-stranded
binding protein? - ANSWER//a protein that binds to
single-stranded DNA and prevents the
recombination of single-stranded DNA to double-
stranded DNA what is the sliding clamp? -
ANSWER//It's a protein fold that binds to DNA
polymerase and prevents it from falling off the
template DNA strand What are some ways that
mutations arise? - ANSWER//base misincorporation,
chemical mutagenesis, ionizing radiation, genetic
mutagenesis, spontaneous lesions What are some
ways that DNA is repaired? -
ANSWER//proofreading, nucleotide excision repair,
base excision repair, DNA mismatch repair, direct
repair, recombination repair What are examples of
diseases caused by DNA repair deficiency? -
ANSWER//cancer, huntington's diease What is a
promoter? - ANSWER//it's a region of DNA that
initiates transcription of a gene what is a
ribonucleoprotein? - ANSWER//it's a nucleoprotein
that contains RNA (so, a nucleic acid + protein +
RNA) What are the three major steps of the
elongation cycle? - ANSWER//initiation, elongation,
termination what is the function of CRISPR? -
ANSWER//it can alter/change genome what is the
mechanism of CRISPR/Cas9? - ANSWER//CRISPR
guides, Cas9 cuts How will CRISPR change the
world? - ANSWER//you can alter genes to cure
diseases and create desired genes Which of the
following is true of the properties of triacylglycerols?
Comprehensive Questions and Answers for
2025/2026 Academic Year – Secure Your First-
Time Pass and Avoid Resits
pyrimidine synthesis are regulated by what? -
ANSWER//feedback inhibition what protects labile
intermediates, allows for coordination of multiple
enzyme activities, and maintains a high local
concentration of metabolites and enzymes with
tunnels? - ANSWER//substrate channeling what
things convert NMPs to NTPs? -
ANSWER//nucleotide diphosphate kinase (NDK)
and base-specific kinases what enzyme catalyzes
the reduction of the 2'-ribose carbon of NDPs using
a free radical dependent mechanism? -
ANSWER//RiboNucleotide Reductase which
enzyme converts all four NDPs? -
ANSWER//RoboNucleotide Reductase Name some
of the functions of nucleotides -
ANSWER//synthesis of purines and pyrimidines,
feedback inhibition, synthesis of dNDPs, enzyme
organization and substrate channeling what
balances the synthesis of dNTPs with sequential
binding of dNTPs in the specificity site> -
ANSWER//RNR what shapes the structure of the
catalytic site and determines which NDP binds to
the catalytic site? - ANSWER//Interactions between
dNTP bound in the specificity site and Loop 2 of
RNR What induces a structural rearrangement of a2
and B2 dimers? - ANSWER//dATP binding to the
activity Describe the 3 oligomerizeration states of
the a2 B2 complex - ANSWER//a. activity, catalytic,
,and selectivity sites are occupied a2 and B2 dimers
have weak affinity for each other b. formation of
a2B2 complex a2 dimer is loaded with substrates
and activators. B2 dimer docks and contributes an
electron to the a-active sites complex falls apart and
dNDP dissociates from a-active sites c. dATP binds
to activity site structural change in a-subunits B2
subunit docks differently forms inactive a4B4
octamer Starting from UMP, which 5 enzymes are
needed to synthesize dTMP? - ANSWER//a.
Rubonucleotide kinase (UMP kinase) b.
Ribonucleotide reductase (RNR) c. Nucleotide
diphosphate kinase (NDK) d. dUTP phosphatase
(dUTPase) e. thymidylate synthase Which enzyme
catalyzes the biosynthesis of dTMP from UMP? -
ANSWER//Thymidylate synthase nucleotide bases
are degraded to what? - ANSWER//uric acid or B-
alinine + NH4+ what can excess uric acid
production be treated with? - ANSWER//xanthine
oxidase inhibitors what are two diseases caused by
defects in the purine salvage pathways? -
ANSWER//gout, Lesch-Nyhan syndrome What
enzyme causes a metabolic domino effect whereby
purines are degraded to uric acid? -
ANSWER//adenosine deaminase Deficiency of
which enzyme can cause severe combined
immunodeficiency syndrome (SCID)? -
ANSWER//adenosine deaminase What type of cells
does chemotherapy target? - ANSWER//rapidly
proliferating cells what are some inhibitors of
glutamine amidotransferases? -
ANSWER//glutamine, azaserine, acivicin why is
thymidylate synthase a target for chemotherapy? -
,ANSWER//because it blocks production of dTTP,
which is lethal to rapidly dividing cells Anti-folates
inhibit thymidylate synthase. Name some. -
ANSWER//a. Methotrexate b. Pemetrexed c.
Proguanil d. Pyrimethamine e. Trimethoprim What
are the primary and secondary structures of the
DNA chain? How does the tertiary structure arise? -
ANSWER//primary: AGCT, secondary: double helix,
tertiary: arises in presence of water What are
driving forces that control double helix formation? -
ANSWER//the anti-parallel nature of the strands,
the base pairs Which nucleotides pair with each
other? - ANSWER//A/T, G/C What are the major
factors that control DNA hybridization? -
ANSWER//base pairing, hydrophilic and
hydrophobic interactions Why phosphorus? -
ANSWER//It's a common intermediate, good
leaving groups (has a "goldilocks" hydrolysis"),
stable in water What is telomerase and what does it
do? - ANSWER//An enzyme that adds a repeat
sequence to the 3' end of telomeres and uses its
own RNA to elongate telomeres. This reverses
telomere shortening. what is helicase and what
does it do? - ANSWER//it's an enzyme that moves
along nucleic acid strands and "unzips" them. This
prepares and allows for
transcription/translation/splicing, etc. what is
topoisomerase II and what does it do? -
ANSWER//it's an enzyme that cuts DNA strands to
manage DNA tangles and supercoils. This relieves
strain on the DNA helix what is dna polymerase? -
ANSWER//it's an enzyme that synthesizes DNA
from deoxyribonucleotides what is primase? -
, ANSWER//it's an enzyme that synthesizes short
RNA sequences that are primers. what is ligase? -
ANSWER//it's an enzyme that joins two sections of
DNA through hydrolysis what is a single-stranded
binding protein? - ANSWER//a protein that binds to
single-stranded DNA and prevents the
recombination of single-stranded DNA to double-
stranded DNA what is the sliding clamp? -
ANSWER//It's a protein fold that binds to DNA
polymerase and prevents it from falling off the
template DNA strand What are some ways that
mutations arise? - ANSWER//base misincorporation,
chemical mutagenesis, ionizing radiation, genetic
mutagenesis, spontaneous lesions What are some
ways that DNA is repaired? -
ANSWER//proofreading, nucleotide excision repair,
base excision repair, DNA mismatch repair, direct
repair, recombination repair What are examples of
diseases caused by DNA repair deficiency? -
ANSWER//cancer, huntington's diease What is a
promoter? - ANSWER//it's a region of DNA that
initiates transcription of a gene what is a
ribonucleoprotein? - ANSWER//it's a nucleoprotein
that contains RNA (so, a nucleic acid + protein +
RNA) What are the three major steps of the
elongation cycle? - ANSWER//initiation, elongation,
termination what is the function of CRISPR? -
ANSWER//it can alter/change genome what is the
mechanism of CRISPR/Cas9? - ANSWER//CRISPR
guides, Cas9 cuts How will CRISPR change the
world? - ANSWER//you can alter genes to cure
diseases and create desired genes Which of the
following is true of the properties of triacylglycerols?
