Unit 2 - DNA Replication Flashcards
functional unit of genetic information
Gene
central dogma
the established understanding in biology of genetic information flow (DNA - RNA - Proteins)
basic units that make up genetic material
nucleotides (phosphate - sugar - phosphate - sugar)
which end do we add new nucleotides always
3 ‘ prime carbon
what makes up the DNA’s backbone?
phosphodiester bonds (alternating phosates and sugar deoxyribose)
is dna single or double stranded?
double
guanine always binds to what?
cytosine (G - C) (C-G)
cytosine always binds to what?
guanine (C-G)(G-C)
adenine always binds to what in DNA?
thymine (A-T)(T-A)
adenine always binds to what in RNA?
uracil (A-U)(U-A)
G - C has how many hydrogen bonds?
3
A - T has how many hydrogen bonds?
2
Do viruses have chromosomes?
no because they are not alive, they have genomes
chromosome vs. plasmids
chromosome have essential housekeeping genes with double stranded DNA, plasmids are circular double stranded and contain beneficial genes for the cell but are not essential (plane boarding pass vs. book to read for enjoyment)
viruses have genetic material, not always DNA, sometimes what?
RNA
where are bacterial chromosomes located?
nucleoid
genes organized in clusters are known as what
operons (like silverware drawers)
Binary fission starts when ______ is triggered.
DNA replication
when the new chromosome has one dna strand from the parent helix and one new strand
semi-conservative
replication always proceeds from the ___ to the ____ end.
5 to the 3 prime end
DNA steps in order
- unwind the helix
- initiate DNA synthesis with RNA primer
- Continuous and Discontinuous synthesis of antiparallel DNA strands
- Concurrent synthesis on leading and lagging strands
- proofreading and error correction
What causes initial DNA unwinding in phase 1 of DNA replication
DnaA binding to the 9mers
What opens the DNA helix?
dnaB and DnaC binding after DnaA binding to the 9mers
DnaB and DnaC
Helicases
this is needed to relax the super coiling from the helix so no damage occurs in DNA replication
DNA gyrase
The initiation of RNA primer occurs at what end?
5 prime end
primase
generates RNA primer of 10 - 12 nucleotides that DNA pol 3 uses to begin DNA synthesis
_____ removes primer after replication fork moves?
DNA pol 1
Which strand is continuous?
Leading strand
Which strand is discontinuous?
Lagging strand
which strand moves in the same direction as the replication fork?
Leading strand (continous)
which strand moves in the opposite direction of the replication fork?
lagging strand (discontinuous)
short fragments of DNA on lagging strand are called what?
Okazaki strands
What does DNA pol 1 do with okazaki fragments?
removes the primers from okazaki fragments via 5 - 3 prime and also fills in the gaps left by primer removal
DNA ligase
forms phosphodiester bonds between pieces of DNA and finishes and seals the DNA replication process.
when 2 replication forks collide
termination of replication
replication
DNA is duplicated
transcription
info from DNA is transferred to RNA
translation
info from RNA is used to make proteins
DNA and RNA differences in sugar
DNA = deoxyribose RNA = ribose
DNA vs. RNA differences in base
DNA = thymine (T - A) RNA = uracil (U-A)
In RNA, adenine binds to what?
Uracil (U-A)(A-U)
DNA polymerase makes what and RNA polymerase makes what?
DNA, RNA
What does it mean the closer a region is to the consensus sequence in bacterial transcription?
The stronger the interraction with RNA polymerase
Does RNA polymerase need a primer in transcription?
No it can start RNA synthesis with only RNA polymerase
Transcription is terminated by what?
Stem loop
RNA polymerase complex ______ binds to the -10 and -35 sites of the promoter in transcription.
Sigma
________ is needed to unwind DNA for replication.
DNA helicase
This is where replication starts
oriC (origin of chromosome)
