DNA Junk

Transformation

gaining new dna from somthing else can change genome

the transforming principle is

dna

griffith discovered

transformation with his mice and smooth and rough bacteria

avery discovered

dna is the transforming principle

hershey and chase discovered

the dna is herdiitary materical by labeling it radioactively in bacteriophages

rosalind franklin discovered

dna is coild but she thought single strand

watson and crick discovered

dna is double stranded along with much of its structure

chargaffs rule

a+t g+c

dna replication is semiconservative

after replication in the 2 daghter strands of dna 1 strand is new and 1 strand is old in each one

meselson and stahl discovered

dna is semiconservative with tracking bacteria replication in different isotopes of nitrogen and then seeing the bands in density centrifuge

dna replication happens semidiscontinously

bc 1 strand is being replication constinsouly and the other is being synthesized in fragments

leading strand

strand being synthesized continously

lagging strand/okazaki fragments

the fragments being syntheszed in pieces

dna is made

5’ to 3’

dna is copied

3’ to 5’

5’ end is

phosphate terminus

3’ end is

hydroxyl terminus

relication fork

dna being copied in 1 direction

replication bubble

dna being copied in both directions will eventually burst seperating the fragments

origin of replication

where dna replication starts

helicase

unwinds, uncoils, unzips DNA

single strand binding proteins

bind to each unzipped DNA strand and keeps them apart until replication is complete

primase

since DNA polymease cant start replication primase comes in and srtart it by addinf a 10 ribonucleotide RNA primer at teh beging of replication, adds it to every place a new okazaki strand is started

DNA polymerase lll

now starts by adding deoxynucleotides at the 3’ end of the primer extending DNA from 5’ to 3’

DNA polymerase l

cuts of RNA primer and replaces it with deoxynucleotides DNA

DNA ligase

okazaki fragment also has RNA primer after it is cut out and replaced by deoxynucleotides by DNA polymerase l the fragements are glued together

topoisomerase

relaxes supercoiled DNA before replication fork

as DNA polymerase adds base it also

proof reads, it adds about 50 bases per second in mammals and 500 bases per second in bacteria, and it usually only makes 1 mistake in 10.000

why do we need to make proteins if we eat them

we only eat some of the amino acids and proteins that we need so the ones we do eat are broken down to raw material or amino acids and used for whatever it is they are needed for or they are used to form new proteins that we need bu cant consume

gene expression/ protein synthesis

express or decode your genes to make proteins made up of 2 steps transcription and translation

transcription

takes place in the nucleus, dna unwinds/uncoils and then unzips, transcribing or copying dna begins at a sequence of bases on the dna called the promoter, then rna polymerase binds to the promoter sequence on one dna strand (template) and copies the bases by adding complementary ribnucleotides to make mRNA, a is copied as u bc rna doesnt have t, mrna can exit the nuclues and survive

sense strand

the bit of dna that is copied and later coded

spliceosomes

help in mRNA splicing, settle on either end of the intron and then slowly close together until a loop is formed that is then ct off leaving only exons on the mRNA

post transcription modification

rna intron splicing, poly a tail is added to the 3’ end and g cap is added to the 5’ end

intron

part of mRNA that is never expressed, can’t go into the cytoplasm so must be removed from mRNA

mRNA is the same length

as the DNA it was copied from but after post transcription modification it will be shorter then the DNA it was copied from

mature mRNA is _____________ than DNA

shorter

mature mRNA is

what is left after post trnacription modification this mRNA is ready to go out into the cytoplasm and will survive

exon

part of mRNA that is expressed and not cut out of the mRNA during post transciption modification, can survive outside of the nucleus

codon

the 3 base pairs in mRNA that will code for 1 amino acid

anticodon

the amino acid coded from the complimentary pairs from mRNA, only ue is to bond to codon

start codon

AUG

stop codon

UAA, UAG, UGA

translation

the message on the mRNA is read/decoded as a triplet of bases calleda codon, the decoding/interpreting is done by tRNA which reads the codon b using the genetic code, the gentic code is universal for all living things and is the correlation of codon to the amino acid, the tRNA connects to the codon on mRNA with its anticodon(triplet of bases complimentary to the codon) that carries the coressponding amino acid at its other end, as the codons are decoded by tRNA amino acids are joined together

post translation modification

protein folding into correct tertiary structure

wobble hypothesis

even if the 3rd base changes in a codon it will most likely code for the same amino acids, this is bc the 3rd base is most likely to mutate and therefore nature made it so these mutations should go unnoticed, the 3rd base and change and the protein created will be the same

transposons

jumping genes, spontaeous cause unknown, move from one location in dna to another, causes mutations, not noticed if the change stays in the intron

missense mutation

substitution

gene regulation

genes are switched on and expressed when the cell needs the proteins and switched off whe the proteins arent needed

exons

coding regions of gene on DNA that ar expressed into proteins

introns

noncoding regions between exons intervening, not expressed

lac operon

genes that control the metabolim of lactose

operon

group of genes that work together to do something

functional genes in lac operon

r p o, they control the function of the other genes by turning the on and off

structural genes in lac operon

z y a, genes that are expressed and code for the proteins and enzymes that metabolize lactose

r

regulator gene that produces repessor protein

p

promotor, where RNA polymerase bonds

o

operator, where the repressor protein binds

allo-lactose

inducer, binds to repressor and pulls it off of the operator

lac operon explained

sequence is rpozya, the repressor protein taht is formed by the regulator gene loved the operator gene and the moment it is made and released it moves and binds to the operator, this leads to the RNA polymerase taht is bonded to the promoter gene behind the operator gene to get stuck and not be able to continue transcription of zya and therefore there are no enzymes produced, once lactose is ingested allo-lactose an inducer comes in and takes the repressor protein off of the operator, this allows RNA polymerase to continue transcription which in turn creates teh proteins and allows lactose to be metabloized

e-coli

where lac operon is, not pathogenic so not bad, good in small amounts

when is the lac operon off

when there is no lactose and the repressor protein is free to stay binded to the operator

when is teh lac operon on

when there is lactose and the allo-lactose takes the repressor protein off of teh operator allowing transcirption

trp operon

synthesizes tryptophan

trp operon explained

the trp operon creates typtophan so when things like turkey or milk with tryptophan in it are ingested and tehre is tryptophan there is not need for trp operon to synthesize more so this is when the trp operon is off, when there is no moer tryptophan in teh system the trp operon turns on to synthezie more

when is the trp operon off

when there is tryptophan

when is the trp operon on

when there is no tryptophan

cleaving

isoltaing the donor gene from the rest of the DNA sequence

restriction enzymes

chemical scissors that recognize specific base sequences of DNA to cut out and around, ex. EcoRI enzyme for E coli cuts GAATTC

vector

vechile that carries the gene

plasmid

circular piece of self-replicating DNA found in bacteria that carries several genes including antibiotic resistance genes which serve as a genetic marker

recombinant gene

the spliced donor gene in a bacteria’s plasmid

transformation

bacteria that contains recombinant DNA

how insulin is made

first teh insulin gene is isolate and cleaved by the restriction enzyme EcoRI , after this the DNA is placed in a plasmid that had part of its DNA seqeunce removed to make room for the human DNA, after this the plasmid is placed back into the bacteria that then reprodcues and allows its DNA to replicate like normal meaning that it is also replicating the transformed plasmid or recombinant DNA creating insulin

cloning

asexual reproduction of cells to produce identical cells

human genome project

map the location of all the genes on the human chromosomes

polymerase chain reaction PCR

make multiple copies of DNA using enzymes DNA polymerase and deoxynucleotides

electrophoresis

seperation of macromolecules using electric current, used to compare DNA from different individuals/sources and to determine molecular mass of DNA, RNA, proteins

DNA fingerprinting

DNA from each individual is unique and gives a unique pattern like our fingerprints when the DNA is cut with restriction enzymes and seperated by a process called electrophoresis

inbreeding

2 lose sibling organisms with same traits

selective breeding

crossing 2 organisms with different traits to get desired traits from both organisms in the offspring

silencer

regulator DNA elements that reduce transcription from their target promoters

homeotic gene

regulate anatomical strucutres in various organisms

oncogene

a gene in which certia circumstances can turn into a tumorous gene

carcinogen

substance capacble of causing cancer

enhancer

activates transcription levels to higher levels then if it wasnt there

protooncogene

genes that help cells grow

lytic viruses

phages that shoot DNA into host bacteria and take over bacteria and reproduce bacteria in the cell, when the baby phages are made they burst ope the bacteria and are released host cell dies

lysogenic

these phages do not kill their bacterial host they shoot the DNA in and incorporate their DNA in the bacterial DNA, as the baterial AND replicates the viral DNA is introduced into the cell, transduction is used

transduction

process in which forgein DNA is introdued into a cell using a virus

enzyme reverse transcriptase

RNA→DNA before it can be turned into a protein

transformation

introducing naked DNA into a cell to change/transform traits

recombinant DNA

dna from 2 different organisms

conjunction

exchange of DNA in bacteria through pili during mating

cDNA

complemntary DNA, DNA molecule made in vitro using mrNA as template and the enzyme reverse transcriptase, corresponds to gene but lacks the introns present in the DNA of the genome

radioactive probes

labeled nucleic acid molecules used to find specific gene/other nucleotide sequenes within the mass of DNA

RFLP

restriciton fragement length polymorphisms, diffrences in homologs DNA seqences that are reflected in different lengths of restriction fragments roduced when DNA is cut up with restriction enzymes

teolmeres

repetitive DNA at chromsome ends also have protetive function, significant loss of telomeric DNA quickly leads to cell death, abnormal length may help immortal cancer cells evade normal cell agging

chromosome puff

chromosome regions that puff out to copy DNA to mRNA during transcription

gene therapy

alterations of individual gene in people with disorders to replace/supplement defetive gene with normal gene/allele