Module 5 Flashcards
From Genome to Protein
Beadle and Tatum
theorized one gene one polypeptide
when was DNA discovered?
identified as the molecule of inheritance?
1800s
1950S
what was the Avery, Macleod, McCarty experiment
when DNA has been degraded, cells do not develop
hershey chase experiment
2 phages identified with 2 different markers
(1 on protein coat 1 on dna)
when phages infect bacteria only the dna marker is passed on
______ is responsible for heredity
pellet
35S
characteristics of DNA
Deoxynucleotide 5’ triphosphare
free hydroxyl group
links 5’-3’
double helix structure running antiparallel (complementary)
can be denatured
does DNA itself have structural organization?
explain
no
dna is organized into chromosomes
how do chromosomes pack in bacteria, eukarya, and archaea
bacteria: supercoiled by topoisomerase
Eukaryotes: histone proteins
archaea: supercoiled and histone proteins
extrachromosomal DNA
codes for non essential functions (toxic pathogens)
packed into mitochondrion and chloroplasts
DNA replication process is
semiconservative
location of origin bacteria/euk
one in bact
multiple in euk
consequence of bidirectional replication
creating leading/lagging strands, okazaki fragments, discontinuous fragments, and need for 2 DNA polymerases to attach to the replisome
DNA Poly 1
removes RNA primer, replaces with newly synthesized DNA
DNA poly 3
main enzyme that adds nucleotides in the 5’-3’ direction
helicase
opens helix by breaking H bonds
Ligase
seals gaps in okazaki fragments
primase
synthesizes RNA primers to start replication
SSBP
bind to single strand DNA to prevent H bonds with itself
Sliding clamp
holds DNA poly 3 as nucleotides are added
Topoisomerase 2
relaxes supercoiled chromosomes
Topoisomerase 4
breaks chromosomes and releases from eachother then reseals DNA
transcription start and direction
5’-3’ direction with no primer needed (RNA polymerase instead)
result of transcription
RNA which is antiparallel and complementary to the original DNA template strand
promoter regions
specific regions in DNA sequence that promote/initiate transcription
sigma factors
in promoter regions
bacteria have more than one to regulate transcription and respond to environmental changes
non template strand =
coding strand
stem loop
inverted loop where RNA poly pauses and stops
Rho dependent
termination site where Rho causes RNA to release
wobble positions
codons that code for the same AA
how is ribosomal RNA measured
prok and euk
coefficient of sedimentation
prok 70S
euk 80S
relation between tRNA and DNA sequence
will be exactly the same with U intead of T on the RNA
A site
acceptor
P site
peptide, building as reading the condons
E site
exit, let go of read condons
how is translation initiated
by the start condon
ribosomes
pro and euk
pro: 70S (30S+50S)
euk: 80S (40S+60S)
Amino acid carried by initiator tRNA
pro and euk
pro: fMET
euk: MET
Shine Dalgarno
pro and euk
Pro: present
Euk: absent
is transcription and translation simultaneous in pro and euk
pro: yes
euk: no
how is transcription regulated
genetic regulation by control of mRNA production
how is RNA production regualted
control mRNA stability and translation
how is protein production regulated
by controlling protein activity
chaperones
energy dependent process undergoing folding and refolding to add cofactors and help secretion
how to stop transcription
regulators bind to promoter or operator region
processes of genetic regulation and why
genes with essential functions are expressed first
genes are only expressed in needed conditions
done to control amount of protein produced
transcription factor activators
turn on expression
recruit RNA polymerases/sigma factors
how to repress transcription factors
bind to promoter regions
turn off expression
block polymerase/sigma factor binding
Activator CAP
does not bind to promoter until it is coupled with cAMP to form the cAMP-CAP complex
cAMP is the inducer
substrate repressor
repressor wont bind to block until it is coupled with a substrate (trp)
de repression enzymes
sit blocking RNA poly until substrate binds in which is removed itself
how to increase production of a protein at a specific molecular signal
design an activator to target that signal region
operon
1 promoter followed by many genes
regulon
1 regulator (ie activator) with many promoter regions
regulatory RNA
RNA that is not translated (sRNA)
40-400 nucleotides
from non template DNA stand
mechanisms of sRNA activity
affect mRNA stability by protecting or targeting RNA degradation
block RBS to block translation
change secondary structure (a/B)
change protein activity without affecting amount of mRNA or protein produced(3)
feedback inhibition, post translation modification, protein sequestration
regulation of protein activity
inhibit feedback inhibition
change enzymatic activity (post translation modification)
remove the protein (sequestration= another bind to block, degradation=destroy to prevent pathway)
how do 2 component regulatory systems work
sensor kinase and a response regulator
feedback loop is regulated by activating/inactivating with a phosphate
