Is rigid with more beta sheets
thermophile
What is the major difference between facultative organisms and aerotolerant anaerobes
facultative organisms grow better w/ oxygen
Has a flexible alpha helix & fewer bonds
Psychrophile
Cross-Linking
Penicillin binding, lose catalytic activity.
Transpeptidation
FtsL
Responsible for rod or bacillus shape of cells
MreB
of Generations=
duration of expo/generation time
unsaturated fatty acids
psychrophile
Can grow in 95oC
hyperthermophiles Archaea domain ONLY
Separation of daughter strands during cell division
FtsK protein
Anchors Z ring to cyto membrane
ATPase
FtsA
Grows at 15oC
psychrophile
has shorter fatty acid chains
psychrophile
Grow at 45oC
thermophile
Forms a Z ring that divides bacterial cells in half
Fts Proteins
the higher the pH
the fewer the H+ ions (more OH) 10times
breaks down H2O2 to oxygen + water
catalase
used to grow a continuous culture in the laboratory
chemostat
Measures cell concentration by turbidity
spectrophotometer
what type of microscope can measure cell counts
phase contrast microscopy
determines cell midpoint during Z ring formation
MIN proteins, middle is most free space
grow best at slightely reduced oxygen levels (3-5% CO2)
Microaerophile
Ten fold Seriel dilution factor
add 10 x each time
cfu/ml=
dilution factor x mL
of cells =
plate count x Dilution Factor/ mL dilution plated
The primase side of template strand
3’ lagging strand
- RNA primer
- Lagging Strand
- Primase
- Single Stranded Binding Protein
- Helicase
- DNA pol III
- Leading Strand
- 5’
Unwinds double helix at replication fork
helicase
lays down RNA at the start of DNA replication
Primase
Seals Okzaki fragments together
ligase
Creates Negative Supercoils in DNA
gyrase
Which direction does sigma recognize promoter sequences
5’ to 3’
The portion of NDA where replication starts is called
origin
Each daugher cell receives a strand of DNA from the parent and newly synthesized complementary strand, what type?
Semi conservative
Proofreading of Replication is performed by
- 3’ to 5’ exonuclease activity of DNA polymerase
- both Pol I & Pol III can do this
Enzyme respobsible for removing RNA primer and replacing with DNA
DNA pol I
Sythesizes leading strand 5’ to 3’
DNA Pol III
What direction does RNA polymerase transcribe
3’ to 5’
Specific DNA sequences that bind RNA polymerase
Promoters
All the DNA sequences are recognized by
sigma factor
- RNA Polymerase Core Enzyme
- Transcription downstream
- Sigma
- mRNA start
- 35 sequence
- Pribnow Box
How do you find an inverted repeat
- One is on the leading strand
- diagonal on the lagging strand & backwards
Which strand do you transcribe?
lagginst strand
How do you form a stem loop
- left side read from left to right
- middle= loop
- right side= right to left, run of uuuus
Signal for the initiation of transcription
- Sigma Factor Recognition of a promoter
What causes the termination of transcription?
stem loop structure, followed by run of UUUs
Initiation of protein sythesis begins with
30S ribosomal subunit.
What is the start codon that always initiates translation
AUG
What does shine dalgarno do?
direct ribosome to proper start site
The site where the growing polypeptide chain is held
P site
The acceptor site, charged tRNA attaches
A site
release factors will bind at termination
A-site
Subunit that first bind to mRNA during translation initiation
Small 30 S
- A- site
- Large 50S Subunit
- Small 30 S Subunit
- E-site
- P-Site
What does a prokaryotic mRNA require to initiate protein sythesis?
Shine Dalgarno sequence and AUG codon
required for termination of protein sythesis in prokaryotes
Stop Codon
23S is
catalyst for peptide bond formation during protein synthesis
A single amino acid may have multiple codons is called
degeneracy
How many hydrogen bonds does cytosine and guanine have
3
Aminoacyl-tRNA sythetase is responsible for…
attachment of amino acid to proper tRNA molecule
Ribosome that holds tRNA to growing polypeptide chain is
P site
What do TAT proteins do?
export folded proteins
What does signal recognition particle do
export unfolded proteins to be inserted into c.membrane
How many hydrogen bonds does adenine tyrosine and uracil have?
2
Reading the codon chart, what do you need to find in the code for start codon?
AUG
What is the codon for the ANTICODON of 5’ GCA 3’
CGU—> UGC (read backwards)
Where a repressor bind in DNA
Operator
Regulatory proteins that bind DNA are
homodimers containing helices
Positive transcriptional regulation
- Lactose induction (not catabolite)
- where the regulator is located
A regulatory system monitoring/ responding to cell density
- quorum sensing, can count, upstream
- before gene product is made
Regulation that responds to external environment
signal transduction
When lactose is present what occurs?
lactose inducer binds the latose repressor
In positive regulation activator proteins stimulate transcriptional activity by
- making a promoter more easily recognized
- bound by sigma factor
Inducer
- repressor cannot bind
- an effector
Corepressor
an effector, repressor binds
Organisms will use glucose before any other sugars
catabolite repression
How many hydrogen bonds does cyto
- Ribose
- Deoxyribose (h only)
- Where amino acid attaches
- 3’ End
- 5’ End
- Anticodon
- A) Lagging phase
- B) Exponential
- C)Stationary
- D) Death
Why bacteria is measured in cfu/ml
because replicate forming a cluster. Hard to measure individual bacteria
Antiparallel
parallel but opposite directions. 5’ to 3’ and 3’ to 5’.
Positive supercoiling
overwinding, tightening
Negative Supercoiling
unwinding, twists in the opposite direction
Why is primase important for DNA synthesis
- cannot initiate synthesis witout primer
- needs a double stranded region to attach, rna does not have this
- rna primer
The first amino acid added to a growing polypeptide chain
f-met
in mRNA which end is translated first
5’
5’ end terminated with a ( ) group
phosphate
3’ end terminates with a ( ) group
OH
What regulates tryptophan operon?
leader and attentuator regions
when tryptophan is plentiful?
- transcription and translation are almost simultaneous
- ribosome is close behing rna polymerase
When tryptophan is low
- termination signal does not occur and transcription continues.
- ribosome stalls to allow RNA pol to move ahead
What distinguishes a strong promoter from a weak promoter?
- will have a better match to the -10 and -35 consensus sequences
A regulon
- manages many different operons
- operons is multiple genes transcribed together
why cell myst synthesize lagging strand in small fragments
because it is going in opposite direction of helicase
What does TAT stand for?
Twine Arginine Translocase
Five things present in leader sequence for attenuation
- stop codon
- encodes 2 TRP amino acids
- ribosome stall at 2 & 3
- run of UUUUUs
- transcription stalls