Bch 5413 Complete Examination Test Questions With Verified Solutions

BCH 5413 COMPLETE EXAMINATION TEST
QUESTIONS WITH VERIFIED SOLUTIONS

●● 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