BIO Unit 4 key words Flashcards
Transformation
A change in geno. & pheno. due to the assimilation of a foreign substance by a cell
T2 Phage
a virulent bacteriophage which infects E. coli bacteria.
Radioactive sulfur
Labels DNA or RNA
Radioactive Phosphorus
Marks DNA not protein
Chargraff’s rules
complimentary bases
Complementary Base Pairings
T-A C-G U-A
X-ray measurement
Measurements that keep pairings in
purine-purine pair
Paring that’s too wide
pyrimidine-purine pair
Pairing that fits/work
pyrimidine-pyrimidine pair
Paring that’s too short
DNA Replication
When a cell copies a DNA molecule + each strands serves as a template for ordering nucleotides into a new complimentary strand
Semiconservative model of replication
Remarkably accurate—only 1 error per billion nucleotides
Origin of replication
the genomic regions at which DNA replication starts
Replication forks
Y-shaped region in a cell where DNA helicase unwinds the double helix of DNA, creating two single-stranded templates.
Helicase
Untwist & separates the template DNA strands at the replication fork
Single stranded binding proteins
keep the unpaired strands apart during replication
DNA polymerases
Catalyze the elongation of new DNA at a replication fork
Polarity
opposite poles that can either attract or repel each other.
Nucleoside trophosphate
Raw nucleotide, each has a nitrogen base, DNA, & triphosphate tail
Hydrolyzed
the last 2 P in Nucleoside trophosphate, a chemical process in which a molecule of water is added to a substance
Exergonic hydrolysis
chemical reaction that releases energy in the form of heat or work.
Polymerization
monomers (1) —> polymers (2+)
Antiparrel
strands in the double helix
Leading strands
can be used by polymerases as a template for a continous complimentary strand (3’ –> 5’)
Lagging strands
is copied away from the fork in short segment (Okazagi fragments) (5’–>3’)
Okazagi fragments
Lagging strands
DNA ligase
enzyme that joins DNA strands together by forming phosphodiester bonds.
OH
Hydroxide
Catalyze
to make a chemical reaction happen or happen more quickly
Topisomerase
corrects “overwinding”
Primase
an enzyme that synthesizes short RNA sequences called primers
Germ-line cells
ensuring that zygotes have long telomere
Telomerase
uses a short molecule of RNA as a template to extend 3’ end of telomere
Telomeres
special nucleotide sequence (allows DNA to get shorter )
Xerodema pigmentosum
hypersensitive to sunlight
Nuclease
cuts out a segment of a damaged strand
Nucleotides exclusion repair
a pathway that repairs replicating DNA throughout the cell cycle.
Central Dogma
DNA -> RNA -> protein
Transcription
the process by which a cell makes an RNA copy of a piece of DNA
m(messenger)RNA
only RNA that gets translated
RNA polymerase
separates DNA strands & bonds RNA nucleotide as they bp
DNA mark
where gene transcription begins & ends
TATA box
2 H bonds
promoter
binds to here to start transcription
Transcription unit
what gets transcribed
Ribozyme
fxns as an enzymes = organic catalyst
Alt. RNA splicing
2 or more diff. polypeptides–treated as exons
HGP
Human Genome Project
single gene
several RNA polymerase
5’ cap
end of the molecule which terminates in a 5’ phosphate group.
poly (A) tail
helps export
termination signal
found at the end of the part of the chromosome being transcribed during transcription of mRNA
RNA splicing
process that removes the intervening, non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons) together in order to enable translation of mRNA into a protein.
introns
NONcoding segments (have to get removed)
extrons
coding regions
splicesosomes
proteins & small nuclear rna
snRNA
small nuclear RNA molecule
t(transfer)RNA
transfer aa from the cytoplasm to a ribosomes
anticodon
a sequence of three nucleotides (a trinucleotide) found at one end of a transfer RNA (tRNA) molecule
codon
3 groups of nucleotide in mRNA
wobble
the 3rd pairing doesn’t have to pair
A U C
U A A
aminocyl–tRNA synthetase
will recognize the tRNA and aa combination
E site
discharge tRNA leave the ribosome
subunits
joins to form a ribosome only when they attach to an mRNA molecule
A site
carries the tRNA w/ the next aa
P site
holds tRNA carrying the growing the polypeptide chain
Intiation
brings together mRNA, a tRNA w/ 1st aa & 2 ribosomal subunits
methionine
used in translation initation complex
codon recongition
occurs btw mRNA condon under A site w/ corresponding anticodon of tRNA carrying appropriate era
elongation
consist of a series of 3 step cycle as each aa is added to the proceeding one
peptide bonds formation
rRNA catalyze the formation of a peptide bonds btw the polypeptide in P site w/ new aa in A site
translocation
the ribosome moves the tRNA w/ the attached polypeptide from the A site –> p site
release factor
binds to the stop codon & hydrolyze the bond btw the polypeptide & its tRNA in the p site
stop codons
stops
polyribosome
multiple ribosomes
template strands
provide a template for ordering the sequence of nucleotide in RNA transcript
AUG
UAA
stop codon
UAG
stop codon
UGA
stop codon
point mutations
results in replacement of a pair of complimentary nucleotide w/ another nucleotide pair
base pair substitution
basically insertions/deletions
silent mutation
alt. of nucleotide still indicate the same aa bc of redundancy in the genetic code
insertions
addition of nucleotide in a gene
missense mutations
still code for an aa but change the indicated aa
nonsense mutations
change an aa codon into stop codon nearly always leading to a nonfunctional protein
deletions
lose of nucleotide in a gene
frame shift mutations
a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read
DNA technology
scientists can manipulate DNA
GMO
Genetically modified organisms
GM foods
Genetically modified food
Transgenic Organisms
an organism or cell whose genome has been altered by the introduction of one or more foreign DNA sequences from another species by artificial means
Plasmids
skeleton
vectors
a DNA molecule that is used as a vehicle to carry a particular DNA segment into a host cell as part of a cloning or recombinant DNA technique.
cDNA
doesn’t contain introns
restriction enzymes
proteins that cleave DNA at specific sites
restriction fragments
cuts that produce Dna
short tandem repeats (STR)
repetitive sequences of DNA that are repeated various times in the genome
gel elecotrophesis
used to separate DNA fragment
PCR
technique that amplifies DNA sequences rapidly and easily
DNA fingerprinting
forensic science
capillary electrophresis
is used to separate these fragments
DNA sequencing
the process of determining the sequence of nucleotide bases (As, Ts, Cs, and Gs) in a piece of DNA.
Sanger termination method
type of DNA sequencing
Sanger sequencing
think of it as combining a form of PCR & type of electrophoresis
ddNTP
Dideoxynucleotides
didoxynucleotide
chain-elongating inhibitors of DNA polymerase
DNA probes
a single-stranded sequence of DNA or RNA that is used to identify specific sequences of DNA or RNA
cystic fibrosis allele
ex of DNA probe
human gene therapy
medical technique that modifies a person’s genes to treat or prevent diseases
CRISPR (clustered regularly interspaced short palindromic repeats)
another defense mechanism of bacteria to combat viruses
CAS 9
enzyme that binds to guide RNA that can be engineered to bind a specific target DNA sequence
operons
in pro genes for related enzymes are often controlled together by being grouped into regulatory units
lac operon
produces enzymes that breaks down lactose only when lactose is present
