BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL
CORRECTLY VERIFIED 2023.Qualified
DNA = phosphate + deoxyribose sugar + A/T/C/G
o Contains two strands. The strands are antiparallel (opposite each other).
o 5’ → 3’
3’ ← 5’
RNA = phosphate + ribose sugar + A/U/C/G
o Single strand, can fold back onto itself and form pairs between itself
(stem‐loop).
Each nucleic acid is made up of polymers (many monomers) that are
called nucleotides.
o Nucleotides contain one or more phosphates, a five‐carbon sugar, and a nitrogen base.
o Nucleotides are always made in the 5’ to 3’ direction.
o 5 is always the beginning of the strand, 3 is the end where nucleotides are added.
DNA organization: DNA is wrapped around proteins called histones →
nucleosome → chromatin fiber→chromosomes
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL
CORRECTLY VERIFIED 2023.Qualified
Steps to the central dogma:
o Coding DNA → template DNA → mRNA → tRNA (amino acid)
o DNA → transcribed to mRNA → translated to protein
o Each step is complementary (opposite) to the previous step, but if you skip a step it will
be identical to the previous step.
o Example
1. Coding DNA strand 5’ AAA TTT GGG CCC 3’
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL
CORRECTLY VERIFIED 2023.Qualified
2. Template DNA strand 3’ TTT AAA CCC GGG 5’
3. mRNA 5’ AAA UUU GGG CCC 3’
4. tRNA Lys Phe Gly Pro
Pairing:
o DNA: A → T
o RNA: A → U
DNA replication:
o Because DNA is a double helix, one strand can be separated and serve as a template for
synthesis of anew strand.
o Semi‐conservative: each copy of DNA contains a template strand and a new strand.
o Steps of replication:
, BIOCHEM C785 Kaleys Comprehensive Study Guide final Correctly Verified 2022
o 1. The DNA must be separated, creating a replication fork. This is done by
helicase.
o 2. Primase attaches an RNA primer, where the replication is to start.
o 3. DNA polymerase adds bases to the remaining of the strand until it reaches a stop
codon. Thisis done in fragments, called okazaki fragments.
If an error is detected, it removes the nucleotides and replaces them with correct
ones,known as exonuclease.
o Exonuclease removes all of the RNA primers, and DNA polymerase fills in those
gaps.
o DNA ligase seals the two strands forming a double helix.
DNA → transcribed → mRNA → translated → protein
Transcription occurs in the nucleus:
o Initiation: RNA polymerase binds to a sequence of DNA called the promoter, found
near the beginningof a gene. Each gene has its own promoter. Once bound, RNA
polymerase separates the DNA strands, providing the single‐ stranded template needed for
transcription.
BIOCHEM C785 Kaleys Comprehensive Study Guide final
CORRECTLY VERIFIED 2023.Qualified
DNA = phosphate + deoxyribose sugar + A/T/C/G
o Contains two strands. The strands are antiparallel (opposite each other).
o 5’ → 3’
3’ ← 5’
RNA = phosphate + ribose sugar + A/U/C/G
o Single strand, can fold back onto itself and form pairs between itself
(stem‐loop).
Each nucleic acid is made up of polymers (many monomers) that are
called nucleotides.
o Nucleotides contain one or more phosphates, a five‐carbon sugar, and a nitrogen base.
o Nucleotides are always made in the 5’ to 3’ direction.
o 5 is always the beginning of the strand, 3 is the end where nucleotides are added.
DNA organization: DNA is wrapped around proteins called histones →
nucleosome → chromatin fiber→chromosomes
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL
CORRECTLY VERIFIED 2023.Qualified
Steps to the central dogma:
o Coding DNA → template DNA → mRNA → tRNA (amino acid)
o DNA → transcribed to mRNA → translated to protein
o Each step is complementary (opposite) to the previous step, but if you skip a step it will
be identical to the previous step.
o Example
1. Coding DNA strand 5’ AAA TTT GGG CCC 3’
,BIOCHEM C785 KALEYS COMPREHENSIVE STUDY GUIDE FINAL
CORRECTLY VERIFIED 2023.Qualified
2. Template DNA strand 3’ TTT AAA CCC GGG 5’
3. mRNA 5’ AAA UUU GGG CCC 3’
4. tRNA Lys Phe Gly Pro
Pairing:
o DNA: A → T
o RNA: A → U
DNA replication:
o Because DNA is a double helix, one strand can be separated and serve as a template for
synthesis of anew strand.
o Semi‐conservative: each copy of DNA contains a template strand and a new strand.
o Steps of replication:
, BIOCHEM C785 Kaleys Comprehensive Study Guide final Correctly Verified 2022
o 1. The DNA must be separated, creating a replication fork. This is done by
helicase.
o 2. Primase attaches an RNA primer, where the replication is to start.
o 3. DNA polymerase adds bases to the remaining of the strand until it reaches a stop
codon. Thisis done in fragments, called okazaki fragments.
If an error is detected, it removes the nucleotides and replaces them with correct
ones,known as exonuclease.
o Exonuclease removes all of the RNA primers, and DNA polymerase fills in those
gaps.
o DNA ligase seals the two strands forming a double helix.
DNA → transcribed → mRNA → translated → protein
Transcription occurs in the nucleus:
o Initiation: RNA polymerase binds to a sequence of DNA called the promoter, found
near the beginningof a gene. Each gene has its own promoter. Once bound, RNA
polymerase separates the DNA strands, providing the single‐ stranded template needed for
transcription.
BIOCHEM C785 Kaleys Comprehensive Study Guide final
