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59 Cards in this Set
- Front
- Back
Fred Griffith
How did his experiment work? -Rough cells transformed to pathogenic smooth cells |
-Attempted to develop vaccine for pneumonia
-showed bacterial transformation -heat killed deadly Smooth, harmless rough injected, smooth plasmid went to live rough |
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Hershey and chase
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-Showed DNA (phosphate) not protein (sulfur) is the genetic material
-sulfur in protein coat, after replication sulfur found in blend but not in cell, protein not injected -phosphate inside cell, after replication not found in blend but in cell, DNA injected |
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bacteriophages what are they?
2 parts, one actioin |
viruses that infect cells
-DNA and protein coat -inject hereditary material into cell |
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DNA Nucleotide
3 Parts? |
Phosphate, sugar, nitrogen base
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How many different nucleotides
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8
DNA/RNA each have four nucleotides |
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How many different nitrogen bases
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5
A, T, C, G, and uracil for thymine in RNA |
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A
DNA |
goes with T
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T
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goes with A
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C
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goes with G
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G
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goes with C
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U
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goes with A
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A
RNA |
goes with U
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x- ray diffraction image?
action and limiting factor relation to DNA |
beam of x-ray directed at a molecule,
calculates position of atoms but not molecular structure -not easy for diffraction unless spooled (dna) |
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Semiconservative nature
DNA Replication- copying itself |
strand splits, two new strands,
Half new/ Half old |
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How does
DNA Polymerase build? |
builds on 3 prime end
there is a bondable -OH hydroxyl group |
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structure of DNA
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double, deoxyribose
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structure of RNA
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single, ribose
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definition
DNA ligase |
enzyme seals
short nucleotide strands into continuous strand seals cut ends, joins phosphate |
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who does DNA
repair? |
ligase, polymerase,
others ligase helps with repairing restrictioin |
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Transcription
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making RNA from DNA
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promotor
25,000 for that many genes in humans |
start of transcription
polymerase attaches to |
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RNA polymerase
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builds RNA strand
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polysome
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group of ribosomes that use the same mRNA transcript over and over
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Mature RNA
introns-not needed exons, left in |
poly-A tail, wound up, 200 adenines, helps in nucleotide production chopped off
guanine cap formed in the nucleus and leaves shortly |
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translation
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assembling amino acids using mRNA template
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codons
20 amino acids |
64 of them,
triplets, translates to an amino acid 61 make acids, 3 are stop one is a start methionine |
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tRNA
has anticodon |
transfers amino acids to specific codons on mRNA
anticodons complimentary to codons, can be deciphered |
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-initiation
-elongation -termination |
-tRNA starter and transcript onto a ribosome, initiation complex is big and small ribosomal subunit
-polypeptide chain forms as transcript moves through, threading a needle -stop codon, transcript is released by enzyme action |
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gene mutations
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small scale changes in nucleotide sequenence
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base pair substitution
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wrong nucleotide is substituted
no change or wrong amino acid is put into protein |
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frameshifts
cause big problem after where shift occurs |
insertions, deletions
change the 3 at a time reading frame, |
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transposable elements
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DNA regions that move to other parts of the molecule
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mutation rate
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rate at which mutations occur in replication
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mutagens
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mutation causing elements such as
ionizing radiatioin |
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alkylating agents
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carcinogens, add ethyl group making more susceptible to break
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aptosis
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name for cell destruction
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ICE-like proteases
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protein cleaving enzymes
method of death |
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gene regulation-
not all genes are expressed at the same time |
regulatory proteins:
negative and positive control systems |
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Lac operon
in prokaryotes (negative) |
promotor, operator, 3 enzymes
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operator
(negative |
binding site for repressor that blocks transcription by RNA polymerase
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repressor
(negative) |
shape altered by lactose,
sugars, wont bind if shape altered, allosteric |
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positive control
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activator pushes RNA polymerase,
allosteric site allows activator to bond, doesn't happen when no allosteric |
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activator protein
allosteric |
CAP binds to polymerase and pushes it
needs cAMP to bind, around when not much glucose |
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positive vs negative
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positive works when allosteric intervention
negative stopped by allosteric intervention |
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cell differentiation
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allows cells in multicelled organisms to become varied and specialized in function
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hormones
enhancers |
signalling molecules
enhancers are base sequences that are binding sites |
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phytochrome
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plant reacts to sun
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tumor
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cancerous tissue mass
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oncogene
disruption of cell cycle |
gene having the potential to induce cancerous transformation
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metastasis
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abnormal cell migration and infiltration
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recombinant DNA technology
recombinant DNA |
analysis of genetic changes
DNA of 2 organisms, started with plasmids |
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vector
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plasmid or virus carries a gene from one organism to another
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plasmid
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loop of DNA outside of main DNA strand
not essential for survival can be transferred |
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restriction enzymes
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cut DNA at specific sites, usually cause sticky ends
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polymerase
chain reaction amplification technique |
amplifies DNA
1)segment 2)primer finds start section, heat splits DNA 3)add nucleotides and ligase repeat |
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cDNA
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copied DNA, reverse transcribed from mature RNA with introns snipped so bacteria can read
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DNA library
RFLPs |
collection of cut segments
differences of electrophoresis patterns, DNA fingerprint |
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Electrophoresis
crime scene |
separates different sizes
mutated genes sections (AAAAATTTTT) identify individuals not part of coding DNA |
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Gene therapy
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replacing faulty gene with normal one
very experimental but shows promise |