Intro to replication

cells make an exact replica of DNA every time the cell divides

DNA replication

What is the sequence of the other strand?

5’-CTGACA-3’

3’-GACTGT-5’

DNA is blank and blank

antiparallel and complementary

DNA replication is blank

Semi-conservative

The 2 original strands come back together after DNA is replicated

Conservative

Copies of DNA are hybrids of original & new DNA

Dispersive

Newly replicated DNA will include 1 of the original strands

Semi-conservative

How many Ori will prokaryotes have?

1

How many Ori will eukaryotes have?

multiple

What is the benefit of having multiple Ori?

faster DNA replication

Which DNA is looped?

prokaryotes

occurs in circular DNA, 1 ori, usually bidirectional

Theta replication

occurs in plasmids 1, ori or unidirectional

Rolling-circle replication

occurs in linear DNA, multiple ori, usually bidirectional

Linear DNA replication

a type of replication common in E.coli and other organisms possessing circular DNA

theta replication

takes place in some viruses and in the F-factor of E. coli

rolling-circle replication

takes place in eukaryotic chromosomes

Linear DNA replication

an enzyme that “reads” the template strand and incorporates complementary base pairs into new strand

DNA polymerase

Why can DNA polymerase only build new strands of DNA from 5’ → 3’?

DNA poly needs to add new nucleotide to both 3’, -OH and the existing DNA strand

unwinds the DNA

Helicase

relivese the tension from unwinding

topoisomerase (eukaryotes), Gyrase (prokaryotes)

SSBs stabalizing ssDNA

single-strand binding protein

adds nucleotides to make a new strand, cannot inititate replication, only make new DNA from 5’ → 3’

DNA polymerase

Creates lagging strand (eukaryotes)

DNA pol δ (delta)

creates lagging leading strand (eukaryotes)

DNA pol (epsilon)

removes primers/replaces gaps (prokaryotes)

DNA pol I

creates leading & lagging strands (prokaryotes)

DNA pol III

nucleotides needed to add to the new strand, 2 phosphates are cleaved off for energy

dNTPs

short stretch of RNA that allows DNA pol to start

Primers

symthesizes primers for DNA replication

primase

joins DNA fragments together (“glue”)

DNA ligase

DNA replication begins with?

dsDNA

Sequences in DNA that signal for replication to begin, Relavant proteins bind to the blank and open a blank.

origin, replication bubble

an enzyme called what unzips DNA into single strands to prepare for DNA replication

helicase

To prevent the what from annealing back together, what attaches to each single strand and hold it in place for replication

ssDNA, SSBs

what synthesizes the what strand, DNA is always synthesisized from what to what

DNA polymerase III (or 3), leading, 5’ → 3’

what synthesizes the what strand, DNA polymerase needs to start at the orgin, but for the blank strands, DNA polymerase must start and stop the strand copy in increments

DNA polymerase III (or δ), lagging

DNA polymerase III (or δ ) synthesizes the lagging strand, First a blank must be added to the single strand so that DNA polymerase can add blank in the correct direction

primers, dNTPs

DNA polymerase III (or δ ) synthesizes the lagging strand, As DNA unzips futher, more blank are added and the blank strand can continute to be made

primers, lagging

Fragments are glued together, and gaps are filled, Blank reconnects DNA fragments

ligase

DNA has been blank, In the end you get blank of the orignal DNA

replicated, a copy

Are hydrogen bonds broken during DNA replication?

Which enzyme is reponsible for breaking the hydrogen bonds?

1. Yes

2. helicase

Which part of the central dogma of biology polymerase DNA involved in?

replication

What should happen to the hydrogen bonds as helicase moves further away?

What prevents the ssDNA from coming back together to form dsDNA

1. come back together to form double helicase

2. SSBs/Single-strand binding proteins

The following strand of DNA is about to be replicated: 5’ - ATGTCC - 3’

Which enzyme is reponsible for adding new nucleotides?

Which directon does DNA polymerase create the DNA replicate?

1. DNA polymerase

2. 5’ side of the replicate to 3’ end of replicate, new replicates are built 5’ → 3’

The following strand of DNA is about to be replicated: 5’ - ATGTCC - 3’

DNA polymerase will add new nucleotides to which end of the replicate?

Which nucleotide (A,C,T,G) would DNA polymerase add first to create the DNA replicate?

1. 3’

2. G

During DNA replication, which copy of the DNA is created continuously?

Leading strand

During DNA replication, which copy of the DNA is created discontinuously?

Lagging strand

During DNA replication, which molecules are required to create the discontinuous strand?

primers

During DNA replication_{, what are the DNA fragments created by the lagging strand called?}

okazaki fragments

During DNA replication, which enzyme is responsible for connecting these fragments into a cohesive strand?

Ligase

Where does DNA replication begin?

How many ORI do prokayotes have?

How many ORI do eukaryotes have?

1. ORI

2. 1

3. multiple

This organisms belongs to which domain life?

How do you know?

1. Eukarya

2. Multiple ori

Is this from eukaryote or prokaryote?

How do you know?

1. Prokaryote

2. Only one ori, and looped DNA

Repetitive sequences at the ends of chromosomes to postpone DNA erosion

telomeres

special enzyme required by telomeres to replicate

telomerase

Why would we need telomeres?

No room at the end of the lagging strand to add a primer

Which one is the oldest and the youngest

Galahad is the youngest because he has the longest telomeres

Lancelot is the oldest because he has the shortest, due to erosion from multiple replication events

How does DNA pol know which bases to add?

complementary pairs

checking the added nucleotide against the DNA template strand

proofreading

enzymes that come in to repair errors that remain after proofreading

mismatch repair

Nuclease removes a segment of DNA, DNA pol adds correct dNTPs, DNA ligase glues fragments back together, type of mismatch repair

nucleotide excision repair

Ultra-violet radiation is an example of a mutagen (induces a mutation)

If DNA bases become damages by UV light, what will happen? will these die?

How can mutations be fixed?

1. a mutation can occur, no these will not die

2. proofreading, mismatch repair/nucleotid excision repair

where does replication begin in bacterial replication?

oriC

specific 245bp segment on their circular chromosome

oriC

protein that binds to start replication

DnaA

Bacterial DNA pol I

removes/replaces primers

Bacterial DNA pol II

DNA repair, restarts replication

Bacterial DNA pol III

elongates DNA

Bacterial DNA pol IV

DNA repair

Bacterial DNA pol V

DNA repair

proteins of origin-recognition complex bind to ARSs to initiate DNA replication

autonomously replicating sequences

required ro bind MCM proteins

Cdc6 & Cdt1

cell divison cycle 6

Cdc6

chromatin licensing & DNA replication factor 1

Cdt1

minichromosome maintenance

MCM

MCM proteins restrict replication to ONCE per cell cycle during which phase?

s-phase

Initiation of DNA synthesis, DNA repair

DNA pol α (alpha)

Lagging strand synthesis, DNA repair

DNA pol δ (delta)

Leading strand synthesis, DNA repair

DNA pol ε (epsilon)

what is responsible for the replication of chromosome ends?

telomerase enzyme

What would be the reult if an oganism’s telomerase enzymes were mutated and nonfuntional?

Chromosomes would shorten each generation