BIOL 1000 Lecture Notes - Lecture 8: Moodle, Ribose, Dna Ligase
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Lecture 8
Carbon Fixation – CO2 added to RuBP to produce two 3PGA molecules
Reduction – NADPH and ATP used to convert 3PGA to G3P, a higher energy molecule to build sugars
Calvin Cycle
A characteristic of the Calvin Cycle is that it makes ATP. FALSE (uses)
At the Nucleus
Telomerase – DNA Polymerase in eukaryotes that extends the end of the lagging strand
See sheet
To start replication you need an RNA primer to start replication by DNA Poly
DNA Poly uses free 3` OH on RNA to begin DNA polymerization
RNA has to be removed and it leaves a gap
o Telomerase (protein + RNA) will replicate the lagging strand end
Video (on Moodle) – DNA Replication
Each new DNA is
semiconservative
DNA Helicase breaks the helicies
apart and the point where it is is
called the replication fork
ssDNA (less stable) are protected
by single stranded binding
proteins (SSB’s)
o called “Stabalizing
proteins”
RNA Primase makes the RNA
Primer required for DNA Poly to
start
o From 5` end only one
primer needed (leading
strand)
o From 3` end primers
required sequentially because it works backwards
2nd DNA Poly the removes the RNA primers puts in the new DNA
DNA Ligase synthesizes the gaps between fragments of DNA because DNA Polymerase can’t
o Note these gaps are called Okazaki Fragments
RNAse removes the RNA primers
E. Coli and Molecular Bio
Selecting for plasmids
Look at Biotech documents
BIOTECHNOLOGY
Plasmids
Only are necessary for when they are selected for
Extrachromosomal DNA
Often carry antibiotic resistant DNA
Genetic Engineering
Ori – origin of DNA replication (different than the genomic ori)
o One genomic ori in bacterial chromosomes
o Many in eukaryotes
Marker allows us to select for bacteria with plasmid
o E.g. amp resistant genome “bla” (β-lactamase which degrades amp)
Promoter is the area that generally attracts and begins the replication
MCS – on plasmids used for genetic engineering
o Not in nature, is synthetic sequence
o Stands for Multiple Cloning Sequence
o Where enzymes (restriction enzymes) can be used to cut plasmid insert foreign DNA
into the cut site
Transformation – put plasmid DNA into cells
o Frequency is about 1:10,000
Organisms used in Biotech
E.g. food is biotech
Use of Bacteria
The Introns stay within the DNA and thus the correct proteins that won’t work
Hard to get into because of Lipopolysaccharide (herd for DNA to pass though)
High protein [] leads to cell death
o So the extra proteins made on the plasmid, if expressed could cause cell to die and the
actual experiment will fail
Eukaryotic Systems
CHO – Chinese hamster ovaries
BHK 1 – Baby hamster kidney