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Chapter 11, chapter 11 pt 2 - Coggle Diagram
Chapter 11
Proteins interacting with DNA
Gene regulation: turning on and off of genes
What does it mean? genes determine nucleotide sequences of mRNA molecules which decides sequence of amino acid in protein molecules
Gene expression: process by which genetic information flows from genes to proteins
Promoter: control sequence; site where RNA polymerase attaches and initiates transcription
Operator: between promoter and enzyme genes; DNA conttrol sequence; determines if it can attach and transscribe
Operon: cluster of genes with related functions; stretch of DNA required for enzyme production
Repressor: binds to operator and physically blocks attachment of RNA polymerase to promoter
regulatory gene codes for repressor
Activators: proteins that turn operons on by binding to DNA and stimulating transcription
11.2 chromosome structure and chemical modifications can affect gene expession
Differentiation: must become specialized with each cell fufilling role
different cells from different genes being expressed
DNA packing
Histones: proteins; provides structural support
Nucleosome: "bead"; DNA wound twice around proteini core of eight histones
Linkers: short stretches of DNA; strings that join beads of nucleosome
Blocks gene expresson by preventing RNA polymerase fro mconctactnig the DDNA
chemical modifications and epigenetic inheritance
Adding CH3 causes chromosomes to become more compact=> reduced transcripton
-COCH3 opens chromatin structure
modifications to DNA and histones can be passed to future generations of cells
Epigenetic inheritance:
inheritance of traits transmitted by mechanisms not directly involving nucleotide sequence
X Inactivation
One X chromosome is compacted to be useless
X chromosome inactivation
initiated in embryonic development
inactive X condenses into compact object called
barr body
matter of chance
11.3: complex assemblies of proteins control eukaryoticc transcription
eukaryotes use regulatory prroteins
transcription factors: proteins that assist eukaryotic RNA polymerase
Initiating gene transcription
binding of activator proteins to DNA control sequences calle d enhancers
DNA bending protein twists the DNA strand bringinig activatos cclose to promoter
once DNA is bent, bound activators interact with other transcription factor proteins; which then bind as a complex at the gene's promoter
large assembly of protein facilitates correct attachment of RNA polymerase to promoter and initiation of transcription
11.5: later stages of gene expressiion are alsso subject to regulation
Breakdown of mRNA
long lived mRNA can be translate into many more protein molecules than short lived ones
bacteria can change their protein production os quickly because prokaryotic mRNA have short life times
Initation of translation
by controlling the start of protiein syntheis, cells can avoid wasting enerrgy if needed components
Protein processing:
proteins undergo chemical modifications to make them functional
11.6: Non coding RNAs play multiple roles in controlling gene expression
microRNA: bind to complementary sequences on mRNA molecules
form sa commplex with one or more proteinss
miNA complex can binid to any mRNA molecule
degrades the tarrget mRNA
If mRNA moelcule matches the esquence along just part of the miRNA then th eocmplex blocks itss translation
small interfering RNAs: changes in structure
blocking gene called RNA interference- RNAi
11.4: Eukaryotic RNA may be spliced in more than one way
alternative RNA splicing
one mRNA ends up with one exon andd the other exon the otherr
organism can produce more than one type of polypeptide from a single gene
chapter 11 pt 2
11.12: Plant cloning shows that differentiated cells may retain all of their genetic potential
Totipotent: capable of produciing eveyr kind fo specialized cell in an organism
Clone: organsm produced thoruugh asexual reproduction from single cell
Regeneration: differentiation need not impair an animal cell's genetic potential
11.14: therapeutic cloning an produe stem cells with great meddical potential
blastocyst: provide embryonic stem cells
goal to produce ES cells to treat diseases called terapeutic cloning
adult stem cells: farther along in differentation than ES cellls
11.10: cells respond to their rneighboing cells with changes in gene experssion
signaling molecule binds to recepto protein and intiating a signal transduction pathway that turns on a gene
signal transduction pathway
series of molecular changes that converts a signal on a taget cell's surface to a specific response niside the cell
cell sending a message ecrete a isngnaling molecule
molecule binds to a specific rerceptor prrotein oftne embeddded in taget cell's plasma membrane
binding activates the firrsst ina seriiee sof erlay proteinis withiini the target cell
last relay molecule in the serries activatese a tansciriptoin factor that tigger trrancriptioni fo gene
tranlationi of the mRNA produce a protien that performs the function orignially called fo by the ssignal
11.13: Biologist can clone animals va nuclear transplantation
nuclear transplantation: animal cloning
Done through:
replacing nucleus of an egg cell or zygote with
nuclear from an injected adult somatic cell
rpeated cell divisoins form blastoyt
if animal being clones is mammal; blastocysst iiis then iimplantedd niot the uterus of a surrogate moher
clones animal will be genetically identical to donor of nucleus: called reproductive cloning
11.8: fuit ffly development proviides an oportunity to examine gene exppression
homeotic gene: master control gene that regulates groups of other genes that determine anatom yof parts of the body
11.9: researchers can moniterr the expression of specific genes
nucleic aid hyprridization: f
11.11: cell signaling system sappearerd early in the evolution of life
cells of mating type a secrete chemical signal called a factor
binds to specific receptor proteins on near by a cells
a cells secrete factor which binds to receptors on a cells