BCH 5413 EXAM 4 STUDY GUIDE COMPLETE
QUESTIONS AND ANSWERS (VERIFIED ANSWERS) |
GRADED A+ | LATEST UPDATE 2025-2026
Central Dogma of Molecular Biology - ANSWER DNA -> RNA -> Protein
endogenous factors that cause DNA damage - ANSWER error in replication
bully addict formation
oxidation
alkylation
hydrolysis
exogenous factors that cause DNA damage - ANSWER UV, chemicals, x-rays,
ionizing radiation
emethanesulfate (EMS) - ANSWER DNA alkylation medicine for cancer
GC base pairing when guanine is exposed to EMS - ANSWER guanine to 06-
ethylguanine and bins to thymine
EMS as a cancer treatment - ANSWER interferes with transcriptional and DNA
replication
alkylation event that does not change base pairing - ANSWER attacks
phosphodiester bond
,endogenous sources of oxidative stress - ANSWER respiration, stress
exogenous sources of oxidative stress - ANSWER smoking, alcohol, pollution,
water, pesticides, medications, food (meat)
Result of oxidative damage - ANSWER guanine oxidation
-biomarker of oxidative stress
-mutagenic
Hoogsteen base pairing - ANSWER - Occurs when one base is in the syn
conformation.
-G-A base pair
UV-A damage - ANSWER free radicals
UV-B damage - ANSWER pyrimidine dimers
Gamma and X-ray damage - ANSWER ss or ds DNA break, altered bases
(oxidized)
ionizing radiation - ANSWER radiation w/enough energy to free electrons from
atoms forming ions, may cause cancer (ex. gamma, X-rays, UV). Ionizes molecules
around DNA ( water) to form highly reactive free radicals that attack DNA
backbone
, oxidative stress, alkylating agents effect on DNA - ANSWER Base modification:
alkylation, methylation, oxidation
polycyclic aromatic hydrocarbons effect on DNA - ANSWER adduct
intercalation between bases
spontaneous events effect on DNA - ANSWER depyrimidation, depurination,
backbone modification, base modifications
ionizing radiation effect on DNA - ANSWER ds break
environmental toxins effect on DNA - ANSWER ss break, DNA-protein crosslink
UV light effect on DNA - ANSWER photoproduct, thymidine dimers
chemo effect on DNA - ANSWER DNA-DNA crosslink
How does proofreading work? - ANSWER when a mismatched pair is
recognized, respositions 3' terminus into other catalytic site with the 3' to 5'
exonuclease site is
removes mismatch
moves 3' back to polymerase site
mistake is corrected
QUESTIONS AND ANSWERS (VERIFIED ANSWERS) |
GRADED A+ | LATEST UPDATE 2025-2026
Central Dogma of Molecular Biology - ANSWER DNA -> RNA -> Protein
endogenous factors that cause DNA damage - ANSWER error in replication
bully addict formation
oxidation
alkylation
hydrolysis
exogenous factors that cause DNA damage - ANSWER UV, chemicals, x-rays,
ionizing radiation
emethanesulfate (EMS) - ANSWER DNA alkylation medicine for cancer
GC base pairing when guanine is exposed to EMS - ANSWER guanine to 06-
ethylguanine and bins to thymine
EMS as a cancer treatment - ANSWER interferes with transcriptional and DNA
replication
alkylation event that does not change base pairing - ANSWER attacks
phosphodiester bond
,endogenous sources of oxidative stress - ANSWER respiration, stress
exogenous sources of oxidative stress - ANSWER smoking, alcohol, pollution,
water, pesticides, medications, food (meat)
Result of oxidative damage - ANSWER guanine oxidation
-biomarker of oxidative stress
-mutagenic
Hoogsteen base pairing - ANSWER - Occurs when one base is in the syn
conformation.
-G-A base pair
UV-A damage - ANSWER free radicals
UV-B damage - ANSWER pyrimidine dimers
Gamma and X-ray damage - ANSWER ss or ds DNA break, altered bases
(oxidized)
ionizing radiation - ANSWER radiation w/enough energy to free electrons from
atoms forming ions, may cause cancer (ex. gamma, X-rays, UV). Ionizes molecules
around DNA ( water) to form highly reactive free radicals that attack DNA
backbone
, oxidative stress, alkylating agents effect on DNA - ANSWER Base modification:
alkylation, methylation, oxidation
polycyclic aromatic hydrocarbons effect on DNA - ANSWER adduct
intercalation between bases
spontaneous events effect on DNA - ANSWER depyrimidation, depurination,
backbone modification, base modifications
ionizing radiation effect on DNA - ANSWER ds break
environmental toxins effect on DNA - ANSWER ss break, DNA-protein crosslink
UV light effect on DNA - ANSWER photoproduct, thymidine dimers
chemo effect on DNA - ANSWER DNA-DNA crosslink
How does proofreading work? - ANSWER when a mismatched pair is
recognized, respositions 3' terminus into other catalytic site with the 3' to 5'
exonuclease site is
removes mismatch
moves 3' back to polymerase site
mistake is corrected
