BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL C
k k k k k k k
ORRECTLY VERIFIED 2023.Qualified k k
• DNAk=kphosphatek+kdeoxyriboseksugark+kA/T/C/G
ok Containsktwokstrands.kThekstrandskarekantiparallelk(oppositekeachkother).
ok 5’k→k3’
3’k←k5’
• RNAk=kphosphatek+kriboseksugark+kA/U/C/G
ok Singlekstrand,kcankfoldkbackkontokitselfkandkformkpairskbetweenkitself
(stem‐loop).
• Eachknucleickacidkiskmadekupkofkpolymersk(manykmonomers)kthatkare
calledknucleotides.
o Nucleotides contain one or more phosphates, a five‐carbon sugar, and a nitrogenbase.
k k k k k k k k k k k k
o Nucleotides are always made in the 5’ to 3’ direction.
k k k k k k k k k
ok 5kiskalwayskthekbeginningkofkthekstrand,k3kiskthekendkwhereknucleotideskarekadded.
• DNAkorganization:kDNAkiskwrappedkaroundkproteinskcalledkhistonesk→knucleosome
→kchromatinkfiber→chromosomes
k
• Stepsktokthekcentralkdogma:
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL C
k k k k k k k
ORRECTLY VERIFIED 2023.Qualified k k
o Coding DNA → template DNA → mRNA → tRNA (amino acid)
k k k k k k k k k k
o DNA → transcribed to mRNA → translated to protein
k k k k k k k k
o Each step is complementary (opposite) to the previous step, but if you skip astep it will be id
k k k k k k k k k k k k k k k k k k
enticalktokthekpreviouskstep.
o Example
▪ 1. Coding DNA strand
k k k 5’kAAAkTTTkGGGkCCCk3’
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL C
k k k k k k k
ORRECTLY VERIFIED 2023.Qualified
k k
▪ 2. Template DNA strand 3’ TTT AAA CCC GGG 5’
k k k k k k k k k
▪ 3. mRNA k 5’kAAAkUUUkGGGkCCCk3’
▪ 4. tRNA k Lysk Phek Glyk Pro
• Pairing:
o DNA: A → T k k k
o RNA: A → U k k k
• DNAkreplication:
o BecausekDNAkiskakdoublekhelix,konekstrandkcankbekseparatedkandkservekaskaktemplatekforksy
nthesiskofkanewkstrand.
o Semi‐conservative:keachkcopykofkDNAkcontainskaktemplatekstrandkandkaknewkstrand.
o Stepskofkreplication:
, BIOCHEM C785 Kaleys Comprehensive Study Guide final Correctly Verified 2022
k k k k k k k k k
o 1.kThekDNAkmustkbekseparated,kcreatingkakreplicationkfork.kThiskiskdonekby
helicase.
o 2.kPrimasekattacheskankRNAkprimer,kwherekthekreplicationkisktokstart.
o 3.kDNAkpolymerasekaddskbasesktokthekremainingkofkthekstrandkuntilkitkreacheskakstopkcod
on.kThisiskdonekinkfragments,kcalledkokazakikfragments.
Ifkankerrorkiskdetected,kitkremovesktheknucleotideskandkreplaceskthemkwithkcorrectkon
es,knownkaskexonuclease.
o ExonucleasekremoveskallkofkthekRNAkprimers,kandkDNAkpolymerasekfillskinkthosekgaps.
o DNAkligaseksealskthektwokstrandskformingkakdoublekhelix.
• DNAk→ktranscribedk→kmRNAk→ktranslatedk→kprotein
• Transcriptionkoccurskinktheknucleus:
o Initiation:kRNAkpolymerasekbindsktokaksequencekofkDNAkcalledkthekpromoter,kfoundknearkt
hekbeginningofkakgene.kEachkgenekhaskitskownkpromoter.kOncekbound,kRNAkpolymeraseksep
arateskthekDNAkstrands,kprovidingktheksingle‐kstrandedktemplatekneededkforktranscription.
BIOCHEMkC785kKaleyskComprehensivekStudykGuidekfinal
k k k k k k k
ORRECTLY VERIFIED 2023.Qualified k k
• DNAk=kphosphatek+kdeoxyriboseksugark+kA/T/C/G
ok Containsktwokstrands.kThekstrandskarekantiparallelk(oppositekeachkother).
ok 5’k→k3’
3’k←k5’
• RNAk=kphosphatek+kriboseksugark+kA/U/C/G
ok Singlekstrand,kcankfoldkbackkontokitselfkandkformkpairskbetweenkitself
(stem‐loop).
• Eachknucleickacidkiskmadekupkofkpolymersk(manykmonomers)kthatkare
calledknucleotides.
o Nucleotides contain one or more phosphates, a five‐carbon sugar, and a nitrogenbase.
k k k k k k k k k k k k
o Nucleotides are always made in the 5’ to 3’ direction.
k k k k k k k k k
ok 5kiskalwayskthekbeginningkofkthekstrand,k3kiskthekendkwhereknucleotideskarekadded.
• DNAkorganization:kDNAkiskwrappedkaroundkproteinskcalledkhistonesk→knucleosome
→kchromatinkfiber→chromosomes
k
• Stepsktokthekcentralkdogma:
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL C
k k k k k k k
ORRECTLY VERIFIED 2023.Qualified k k
o Coding DNA → template DNA → mRNA → tRNA (amino acid)
k k k k k k k k k k
o DNA → transcribed to mRNA → translated to protein
k k k k k k k k
o Each step is complementary (opposite) to the previous step, but if you skip astep it will be id
k k k k k k k k k k k k k k k k k k
enticalktokthekpreviouskstep.
o Example
▪ 1. Coding DNA strand
k k k 5’kAAAkTTTkGGGkCCCk3’
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL C
k k k k k k k
ORRECTLY VERIFIED 2023.Qualified
k k
▪ 2. Template DNA strand 3’ TTT AAA CCC GGG 5’
k k k k k k k k k
▪ 3. mRNA k 5’kAAAkUUUkGGGkCCCk3’
▪ 4. tRNA k Lysk Phek Glyk Pro
• Pairing:
o DNA: A → T k k k
o RNA: A → U k k k
• DNAkreplication:
o BecausekDNAkiskakdoublekhelix,konekstrandkcankbekseparatedkandkservekaskaktemplatekforksy
nthesiskofkanewkstrand.
o Semi‐conservative:keachkcopykofkDNAkcontainskaktemplatekstrandkandkaknewkstrand.
o Stepskofkreplication:
, BIOCHEM C785 Kaleys Comprehensive Study Guide final Correctly Verified 2022
k k k k k k k k k
o 1.kThekDNAkmustkbekseparated,kcreatingkakreplicationkfork.kThiskiskdonekby
helicase.
o 2.kPrimasekattacheskankRNAkprimer,kwherekthekreplicationkisktokstart.
o 3.kDNAkpolymerasekaddskbasesktokthekremainingkofkthekstrandkuntilkitkreacheskakstopkcod
on.kThisiskdonekinkfragments,kcalledkokazakikfragments.
Ifkankerrorkiskdetected,kitkremovesktheknucleotideskandkreplaceskthemkwithkcorrectkon
es,knownkaskexonuclease.
o ExonucleasekremoveskallkofkthekRNAkprimers,kandkDNAkpolymerasekfillskinkthosekgaps.
o DNAkligaseksealskthektwokstrandskformingkakdoublekhelix.
• DNAk→ktranscribedk→kmRNAk→ktranslatedk→kprotein
• Transcriptionkoccurskinktheknucleus:
o Initiation:kRNAkpolymerasekbindsktokaksequencekofkDNAkcalledkthekpromoter,kfoundknearkt
hekbeginningofkakgene.kEachkgenekhaskitskownkpromoter.kOncekbound,kRNAkpolymeraseksep
arateskthekDNAkstrands,kprovidingktheksingle‐kstrandedktemplatekneededkforktranscription.
BIOCHEMkC785kKaleyskComprehensivekStudykGuidekfinal
