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all genese present in a cell or virus
genome
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specific set of genes an organism possesses
genotype
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set of observable characteristics
phenotype
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who injected dead virulent pneumococci and live non-virulent bacteria into mice
girffith
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who radiolabled t2 virus protien coats with s35 and dna with p32 to find the radiolabled stuff inside e.coli?
hershey and chase
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central dogma
- dna makes rna makes protein
- replication to transcription to translation
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what bonds link the nucleotide dna and rna together
phosphodiester bonds
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how are dna and rna different
- nitrogenous baes
- sugars
- single vs double stranded
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what bases do dna contain
adenine, guanine, cytosine and thymine
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what sugar does dna use
deoxyribose
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what bases does rna use
adenine, guanine, cytosine, and uracil
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what sugar does rna use
ribose
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3 types of rna
- ribosomal
- transfer
- messenger
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how do rna molecules differ
- function
- site of synthesis
- structure
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in what organisms is dna found to be circular double helix?
all archaea and most bacteria
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small basic proteins
histones
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combination of dna and proteins
nucleosome
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T/F
archae dna structure is similar to that of eucaryotic cells
true
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how is dna replicatino semiconservative?
- each parental strand is conserved
- two parental strands separate and serve as templates for synthsis of new strands
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what pattern does procayotic dna synthesize?
bidirectional from a single origin of replication
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what replication does viruses and plasmids undergo
rolling circle replication
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length of eucaryotic dna vs procaryotic dna
eucaryotic dna is 1400 times longer
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what is that catalase for the synthesis of complementary dna strands?
dna polymerase
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in what direction does dna sythesize to form a phosphodiester bond
5' to 3'
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template
directs sythesis of complemenatary strand
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primer
whole dna or rna used to start the replication
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how many dna polymerase's does ecoli have
5
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what's the first step of dna replication
- -dna A protien binds to dna A box
- -hydrolizes atp to separate dna strands
- -helicase separates and unwinds dna
- -SSB (binding proteins) bind to keeps DNA single
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topoisomerase
relieves tnesion keeping strands from tangling
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replisome
complex of proteins that incules helicases, ssb protiens, topisomerases, and dna polymerase III
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primase
sythesizes 10bp rna primer
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primosome
protein complex that sythesizes the primer, part of the replisome
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step 2 of dna replication
- -leading strand replicated continuously in 5'-3'
- -lagging strand replicated discontinuously in short fragments (still 5'-3')
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T/F
DNA replicates in the same direction as the template
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okazaki fragments
the lagging strand of dna, requires a primer for each segment
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when does dna replication stop
when replisome reaches termination site (ter) on DNA
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how can the strands separate to stop termination?
topoisomerases have to temporarily break
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basic unit of genetic info
gene
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the nucleic acid sequence that codes for a polypeptide
gene
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mRNA nucleotide triplet that specifies an amino acid
codon
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reading frame
organizatinon of condons such that they can be read to give rise to a gene product
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which strand directs rna sythesis
template (antisense) strand
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where is the promoter located on the gene?
at the start
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shine-delgarno sequence is used in what step
translation
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the coding region on dna begins with what and ends with what
- 3'TAC5' producing AUG
- stop codon
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rna sythesis under the directino of DNA
transcription
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how is the rna transcribed from dna related to the original strand
rna is complementary to dna sequence
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this rna carries the message for protein synthesis
mrna
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this rna carries amino acids during protein synthesis
trna
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this rna is a compononet of ribosomes
rrna
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what kind of mrna is found in bacteria and archaea
polygenic mrna
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transcription in bacteria is cataylized by what
a single rna polymerase
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holoenzyme
core enzyme plus a sigma factor
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3 stages of transcription
- initiation
- elongation
- termination
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promoter
rna polymerase recongnition/binding site
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Ideal sequences composed of the baes most often found at each position when compared to sequences of different bacteria
consensus sequence
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How many basepairs does the RNAP recongition site have?
35
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another name for the RNAP binding site
Pribnow box
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where the RNAP unwinds the DNA
pribnow box
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leader sequence
initially transcribed section that has a Shine-Dalgarno sequence
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Inititaion, direction of the template strand and the non-template strand
- template is 3'-5'
- coding is 5'-3'
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what is a transcription bubble
something that moves with the polymerase as it trascribes mRNA from the template strand. Hybrid DNA/RNA inside
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Transcription termination
occurs when core RNA polymerase dissociates from the template DNA
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some terminators in transcription need what to help with termination
rho factor
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translation
mRNA sequence tranlsated into amino acid sequence of polypeptide chain
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colinearity
sequence of base pairs in DNA corresponds to the amino acid sequence of polypeptide encoded
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codon
gentic code word that specifies for an amino acid
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code degeneracy
up to six different codons can code for a single amino acid
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sense codons
the 61 codons that specify amino acids
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stop (nonsense) codons
3 codons used as a termination signal, don't code for amino acids
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wobble
- loose base pairing
- eliminates need for unique tRNA for each codon
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translation in protein sythesis
synthesis of polypeptide directed by sequence of nucleotides in mRNA
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direction of protein sythesis
N-terminal----> C-terminal
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site of translation in protein sythesis
ribosome
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polyribosome
complex of mRNA with several ribosomes
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Aminoacyl-tRNA Synthetase
attatchment of amino acid to tRNA
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what kind of ribosome are in procaryotes
70S (30S +50s subunites)
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what kind of ribsome are in eucaryotes
80S ribosomes (40S +60S subunits)
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initiator tRNA used in bacteria for protein synthesis
N-formylmethionine tRNA
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initiator tRNA used in eucaryotes for protein synthesis
methionine-tRNA
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Where does IF-3 bind to in initiation of protein synthesis
30S subunit
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which two RNA's bind to the 30s subunit in protein sythesis
mRNA and tRNA
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what does the 50S subunit do in initiatin of protein sythesis
forms a ribosom mRNA complex
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Elongation of protein sythesis
sequential addition of amino acids to growing polypeptide
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3 phases of elongation
- 1. aminoacyl-tRNA binding
- 2. transpeptidation reaction
- 3. translocation
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peptidyl (donor P) site
binds initiator tRNA
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aminoacyl (acceptor A) site
binds incoming aminoacyl-tRNA
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Amino-acyl-tRNAbinding phase
elongation factor brings amino acyl trna to a site
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transpeptidation phase of elongation
amino acid chain P site to A site by peptidyl transferase
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translocation phase on elongation
- peptidyl trna moves form a to p
- ribosome moves down a codon
- empty trna leaves p site
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what aid in recongnition of stop codons
release factors
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peptidyl transferase
hydrolyzes the peptide free from tRNA using energy from gtp
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termination of protein sythesis
ribosome dissociates from mRNA and separates, IF binds to the 30S subunit to keep it from reassocitating with 50S
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molecular chaperones
proteins that aid the folding of nascent polypeptides and protects cell from thermal damage
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