Term
The Molecular Basis of Inheritance |
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Definition
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Definition
•a change in genotype and phenotype due to assimilation of foreign DNA
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Term
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Definition
• Griffith worked with two strains of a bacterium, one pathogenic and one harmless
• When he mixed heat-killed remains of the pathogenic strain with living cells of the harmless strain, some living cells became pathogenic |
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Term
| The discovery of the genetic role of DNA began with research by ________ in _________ |
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Definition
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Term
It was known that DNA is a |
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Definition
•polymer of nucleotides, each consisting of a nitrogenous base, a sugar, and a phosphate group
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Term
Chargaff’s rules state that |
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Definition
•in any species there is an equal number of A and T bases, and an equal number of G and C bases
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Term
The Watson-Crick model explains Chargaff’s rules:
The Watson-Crick model explains Chargaff’s rules:
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Definition
•in any organism the amount of A = T, and the amount of G = C
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Term
Since the two strands of DNA are complementary, each strand |
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Definition
acts as a template for building a new strand in replication |
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Term
In DNA replication, the parent molecule |
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Definition
unwinds, and two new daughter strands are built based on base-pairing rules
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Term
Watson and Crick’s semiconservative model of replication |
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Definition
•predicts that when a double helix replicates, each daughter molecule will have one old strand (derived or “conserved” from the parent molecule) and one newly made strand
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Term
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Definition
| the two parent strands rejoin |
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Definition
| each strand is a mix of old and new |
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Term
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Definition
where the two DNA strands are separated, opening up a replication “bubble”
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Definition
in both directions from each origin, until the entire molecule is copied |
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Term
At the end of each replication bubble is a
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Definition
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Term
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Definition
•a Y-shaped region where new DNA strands are elongating
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Term
Replication begins at special sites called |
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Definition
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Term
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Definition
•are enzymes that untwist the double helix at the replication forks
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Term
What does Single-strand binding protein do? |
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Definition
•binds to and stabilizes single-stranded DNA until it can be used as a template
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Term
what does
Topoisomerase do? |
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Definition
•corrects “overwinding” ahead of replication forks by breaking, swiveling, and rejoining DNA strands
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Term
DNA polymerases cannot .....they can ....
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Definition
| initiate synthesis of a polynucleotide..... only add nucleotides to the 3¢ end |
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Term
The initial nucleotide strand is a short RNA |
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Definition
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Term
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Definition
An enzyme
can start an RNA chain from scratch & adds RNA nucleotides one at a time using the parental DNA as a template
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Term
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Definition
short 5–10 nucleotides long |
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Term
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Definition
•serves as the starting point for the new DNA strand
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Term
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Definition
an enzyme
catalyze the elongation of new DNA at a replication fork |
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Term
Most DNA polymerases require |
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Definition
primer and a DNA template strand
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Term
DNA polymerases add nucleotides only to the free ___ end of a growing strand |
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Definition
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Term
the new DNA strand can elongate only in the ___ to ___ direction
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Definition
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Term
Along one template strand of DNA, the DNA polymerase synthesizes a ______ _____ continuously, moving toward the replication fork |
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Definition
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Term
•To elongate the other new strand, called the_____ _____ , DNA polymerase must work in the direction away from the replication fork
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Definition
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Term
The lagging strand is synthesized as a series of segments called |
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Definition
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Term
Okazaki fragments, are joined together by? |
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Definition
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Term
1 job of
DNA polymerases is to? |
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Definition
•proofread newly made DNA, replacing any incorrect nucleotides
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Term
In mismatch repair of DNA |
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Definition
repair enzymes correct errors in base pairing
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Term
In nucleotide excision repair |
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Definition
•a nuclease cuts out and replaces damaged stretches of DNA
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Term
•Eukaryotic chromosomal DNA molecules have at their ends nucleotide sequences called
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Definition
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Term
Telomeres do not ....... but they do ......
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Definition
| prevent the shortening of DNA molecules ..... postpone the erosion of genes near the ends of DNA molecules |
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Term
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Definition
•catalyzes the lengthening of telomeres in germ cells
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Term
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Definition
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Term
Proteins are the links between |
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Definition
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Term
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Definition
process by which
DNA directs protein synthesis
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Term
•Gene expression includes two stages:
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Definition
| transcription and translation |
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Term
one gene–one enzyme hypothesis was developed by |
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Definition
George Beadle and Edward Tatum |
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Term
| one gene–one enzyme hypothesis states that |
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Definition
each gene dictates production of a specific enzyme |
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Term
one gene–one enzyme hypothesis was later changed to? |
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Definition
•one gene–one polypeptide hypothesis
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Term
RNA is the intermediate between |
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Definition
•genes and the proteins for which they code
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Term
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Definition
•is the synthesis of RNA under the direction of DNA
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Term
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Definition
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Term
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Definition
•is the synthesis of a polypeptide, which occurs under the direction of mRNA
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Term
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Definition
are the sites of translation |
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Term
In prokaryotes, mRNA produced by transcription is |
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Definition
•immediately translated without more processing
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Term
in a
eukaryotic cell, the nuclear envelope separates |
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Definition
•transcription from translation
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Term
•Eukaryotic RNA transcripts are modified through ....to..
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Definition
| RNA processing to yield finished mRNA |
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Term
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Definition
•is the initial RNA transcript from any gene
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Term
•The central dogma is the concept that cells are governed by a cellular chain of command:
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Definition
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Term
There are___ amino acids, but there are only __ nucleotide bases in DNA |
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Definition
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Term
The flow of information from gene to protein is based on a |
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Definition
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Term
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Definition
| is a series of non overlapping, three-nucleotide words |
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Term
the
triplet code is the
______units of uniform length that can code for ....
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Definition
smallest ....
all the amino acids |
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Term
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Definition
| one of the two DNA strands called the template strand provides a template for ordering the sequence of nucleotides in an RNA transcript |
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Term
During translation, the mRNA base triplets called____ are read in the ___ to ___ direction |
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Definition
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Term
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Definition
•specifies the amino acid to be placed at the corresponding position along a polypeptide
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Term
Codons along an mRNA molecule are read by |
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Definition
•translation machinery in the 5¢ to 3¢ direction
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Term
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Definition
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Term
•Codons must be read in the correct ____ _____ in order for the specified polypeptide to be produced
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Definition
| reading frame (correct groupings) |
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Term
Of the 64 triplets, 61 code for.... ; 3 triplets are ..... |
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Definition
amino acids
“stop” signals to end translation |
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Term
Genes can be transcribed and translated after |
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Definition
being transplanted from one species to another |
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Term
Transcription, is the ____ stage of gene expression |
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Definition
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Term
RNA synthesis is catalyzed by |
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Definition
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Term
| What does RNA polymerase do? |
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Definition
| it pries the DNA strands apart and hooks together the RNA nucleotides |
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Term
RNA synthesis follows the same base-pairing rules as DNA, except |
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Definition
•uracil which substitutes for thymine
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Term
The DNA sequence where RNA polymerase attaches is called the |
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Definition
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Term
| in bacteria, the sequence signaling the end of transcription is called the |
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Definition
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Term
The stretch of DNA that is transcribed is called a |
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Definition
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Term
•The three stages of transcription:
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Definition
–Initiation
–Elongation
–Termination
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Term
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Definition
| they signal the initiation of RNA synthesis |
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Term
What do Transcription factors do? |
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Definition
•mediate the binding of RNA polymerase and the initiation of transcription
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Term
The completed assembly of transcription factors and RNA polymerase II bound to a promoter is called a |
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Definition
| transcription initiation complex |
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Term
A promoter called a _____ _____ is crucial in forming the initiation complex in eukaryotes |
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Definition
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Term
The mechanisms of termination in
bacteria is that
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Definition
the polymerase stops transcription at the end of the terminator |
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Term
| The mechanisms of termination in eukaryotes |
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Definition
| the polymerase continues transcription after the pre-mRNA is cleaved from the growing RNA chain; the polymerase eventually falls off the DNA |
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Term
•Enzymes in the eukaryotic nucleus modify.....before.....
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Definition
pre-mRNA......the genetic messages are dispatched to the cytoplasm
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Term
During RNA processing in
eukaryotes
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Definition
both ends of the primary transcript are usually altered |
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Term
The 5¢ end receives a modified nucleotide |
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Definition
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Term
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Definition
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Term
•These modifications share several functions:
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Definition
–They seem to facilitate the export of mRNA
–They protect mRNA from hydrolytic enzymes
–They help ribosomes attach to the 5¢ end
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Term
•noncoding regions are called
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Definition
intervening sequences
OR
introns
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Term
•The other regions are called ....because.... usually translated into .....
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Definition
| exons .....they are eventually expressed.....amino acid sequences |
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Term
| What does RNA splicing do? |
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Definition
•it removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence
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Term
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Definition
• a variety of proteins and several small nuclear ribonucleoproteins (snRNPs) that recognize the splice sites
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Term
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Definition
• they are catalytic RNA molecules that function as enzymes and can splice RNA
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Term
Three properties of RNA enable it to function as an enzyme |
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Definition
–It can form a three-dimensional structure because of its ability to base pair with itself
–
Some bases in RNA contain functional groups
–
RNA may hydrogen-bond with other nucleic acid molecules
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Term
Because of alternative splicing |
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Definition
•the number of different proteins an organism can produce is much greater than its number of genes
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Term
•Some genes can encode more than one kind of polypeptide, depending on which segments are treated as exons during RNA splicing
•Such variations are called?
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Definition
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Term
Proteins often have a modular architecture consisting of discrete regions called |
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Definition
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Term
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Definition
•the different domains in a protein
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Term
•Exon shuffling may result in the
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Definition
| evolution of new proteins |
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Term
•A cell translates an mRNA message into protein with the help of
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Definition
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Term
•Molecules of tRNA are not identical:
–
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Definition
Each carries a specific amino acid on one end
–Each has an anticodon on the other end |
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Term
| the anticodon base-pairs with a |
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Definition
| complementary codon on mRNA |
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Term
•Flattened into one plane to reveal its base pairing, a tRNA molecule looks like a
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Definition
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Term
•Because of ___ ____ tRNA actually twists and folds into a three-dimensional molecule
•
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Definition
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Term
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Definition
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Term
Accurate translation requires |
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Definition
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Term
the 1st step in Accurate translation is? |
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Definition
–a correct match between a tRNA and an amino acid, done by the enzyme aminoacyl-tRNA synthetase
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Term
| aminoacyl-tRNA synthetase is invloved in |
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Definition
the 1st step of Accurate translation |
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Term
2nd step in Accurate translation is |
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Definition
a correct match between the tRNA anticodon and an mRNA codon |
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Term
•Flexible pairing at the third base of a codon is called
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Definition
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Term
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Definition
| some tRNAs to bind to more than one codon |
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Term
•Ribosomes facilitate specific coupling of.....with....in....
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Definition
| tRNA anticodons...mRNA codons....protein synthesis |
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Term
•The two ribosomal subunits (large and small) are made of ____and ____
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Definition
| proteins and ribosomal RNA (rRNA) |
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Term
A ribosome has ___ binding sites for tRNA which are? |
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Definition
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Term
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Definition
–tRNA that carries the growing polypeptide chain
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Term
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Definition
| tRNA that carries the next amino acid to be added to the chain |
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Term
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Definition
| exit site, where discharged tRNAs leave the ribosome |
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Term
•The initiation stage of translation brings together ____, a ___ with the ___ and ____
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Definition
mRNA
tRNA
first amino acid
the two ribosomal subunits
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Term
The 1st step of the initiation stage is that |
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Definition
| a small ribosomal subunit binds with mRNA and a special initiator tRNA |
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Term
Then after the 1st step of the initiation stage is that |
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Definition
the small subunit moves along the mRNA until it reaches the start codon (AUG) |
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Term
The Last step in the initiation stage is that |
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Definition
•Proteins called initiation factors bring in the large subunit that completes the translation initiation complex
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Term
| initiation factors bring in the |
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Definition
| large subunit that completes the translation initiation complex |
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Term
During the elongation stage, amino acids are |
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Definition
added one by one to the preceding amino acid |
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Term
•Each addition in the
elongation
stage/process involves proteins called..... and occurs in .... steps
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Definition
| elongation factors ...three..... |
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Term
The elongation factors occurs in three steps whic are? |
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Definition
| : codon recognition, peptide bond formation, and translocation |
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Term
•Termination occurs when a
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Definition
| stop codon in the mRNA reaches the A site of the ribosome |
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Term
•The A site accepts a protein called a
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Definition
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Term
The release factor causes the |
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Definition
| addition of a water molecule instead of an amino acid |
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Term
| The release factor reaction releases? |
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Definition
the polypeptide, and the translation assembly then comes apart |
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Term
A number of ribosomes can translate a single mRNA simultaneously, forming a |
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Definition
| polyribosome (or polysome) |
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Term
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Definition
| cell to make many copies of a polypeptide very quickly |
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Term
Polypeptide chains are modified after |
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Definition
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Term
•Completed proteins are targeted to
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Definition
| specific sites in the cell |
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Term
•During and after synthesis
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Definition
| a polypeptide chain spontaneously coils and folds into its three-dimensional shape |
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Term
Some polypeptides are .....others..... |
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Definition
•activated by enzymes that cleave then ......
•come together to form the subunits of a protein
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Term
•Two populations of ribosomes are evident in cells:
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Definition
| free ribsomes and bound ribosomes |
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Term
•free ribsomes are in the
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Definition
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Term
| bound ribosomes are attached to the |
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Definition
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Term
What do Free ribosomes do? |
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Definition
they mostly synthesize proteins that function in the cytosol |
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Term
•Bound ribosomes make proteins of the.... and..... that are secreted from the cell
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Definition
| endomembrane system...proteins |
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Term
•Ribosomes are .... and can...
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Definition
| identical....switch from free to bound |
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Term
•Polypeptide synthesis always begins in the
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Definition
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Term
•Synthesis finishes in the .... unless
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Definition
| cytosol....the polypeptide signals the ribosome to attach to the ER |
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Term
Polypeptides destined for the ER or for secretion are marked by a |
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Definition
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Term
• What does A signal-recognition particle (SRP) do?
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Definition
| binds to the signal peptide |
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Term
•The SRP brings the..... and its.... to the....
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Definition
| signal peptide ...ribosome....ER |
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Term
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Definition
changes in the genetic material of a cell or virus |
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Term
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Definition
| chemical changes in just one base pair of a gene |
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Term
•Point mutations within a gene can be divided into two general categories:
–
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Definition
Base-pair substitutions
–Base-pair insertions or deletions |
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Term
A base-pair substitution replaces |
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Definition
•one nucleotide and its partner with another pair of nucleotides
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Term
Silent mutations have .....b/c |
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Definition
•no effect on the amino acid produced by a codon ....of redundancy in the genetic code
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Term
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Definition
| still code for an amino acid, but not necessarily the right amino acid |
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Term
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Definition
•change an amino acid codon into a stop codon, nearly always leading to a nonfunctional protein
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Term
Insertions and deletions are ....and have a..... |
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Definition
additions or losses of nucleotide pairs in a gene.....
•disastrous effect on the resulting protein more often than substitutions do
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Term
Insertion or deletion of nucleotides |
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Definition
•may alter the reading frame, producing a frameshift mutation
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Term
Spontaneous mutations can occur during DNA |
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Definition
replication, recombination, or repair |
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Term
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Definition
•physical or chemical agents that can cause mutations
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Term
•gene can be defined as a
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Definition
| region of DNA that can be expressed to produce a final functional product, either a polypeptide or an RNA molecule |
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Term
Regulation of Gene Expression |
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Definition
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Term
•Prokaryotes and eukaryotes alter gene expression in response
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Definition
| to their changing environment |
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Term
•In multicellular eukaryotes, gene expression regulates ..... and is responsible for .....
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Definition
| development....differences in cell types |
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Term
A cell can regulate the production of enzymes by ....OR by |
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Definition
| feedback inhibition ....gene regulation |
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Term
Gene expression in bacteria is controlled by the |
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Definition
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Term
•A cluster of functionally related genes can be under coordinated control by a single on-off “switch” The regulatory “switch” is a segment of DNA called an.... usually positioned within the...
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Definition
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Term
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Definition
•the entire stretch of DNA that includes the operator, the promoter, and the genes that they control
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Term
The operon can be switched off by a |
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Definition
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Term
•The repressor prevents gene transcription by .... and...
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Definition
| binding to the operator... blocking RNA polymerase |
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Term
•The repressor is the product of a separate
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Definition
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Term
•The repressor can be in an ... or ... form, depending on the...
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Definition
| active...inactive...presence of other molecules |
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Term
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Definition
molecule that cooperates with a repressor protein to switch an operon off |
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Term
By default the ... is on and the genes for... are... |
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Definition
| trp operon....tryptophan synthesis... transcribed |
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Term
When tryptophan is present |
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Definition
it binds to the trp repressor protein, which turns the operon off |
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Term
The repressor is active only |
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Definition
in the presence of its corepressor tryptophan |
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Term
•the trp operon is turned off (repressed)
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Definition
| if tryptophan levels are high |
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Term
•A repressible operon is one that is usually
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Definition
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Term
•binding of a repressor to the.... shuts off ....
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Definition
| operator....transcription |
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Term
Example of a repressible operon |
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Definition
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Term
An inducible operon is one that is usually |
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Definition
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Term
•a molecule called an .... inactivates the .... and turns on...
|
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Definition
| inducer...repressor...transcription |
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Term
Example of an inducible operon |
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Definition
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Term
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Definition
| genes that code for enzymes used in the hydrolysis and metabolism of lactose |
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Term
•By itself, the lac repressor is.... and switches the ...
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Definition
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Term
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Definition
| inactivates the repressor to turn the lac operon on |
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Term
Inducible enzymes usually function in... their synthesis is induced by a.... |
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Definition
| catabolic pathways....chemical signal |
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Term
Repressible enzymes usually function in ...... their synthesis is repressed by... |
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Definition
| anabolic pathways....high levels of the end product |
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Term
Regulation of the trp and lac operons involves ....because |
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Definition
| negative control of genes ....operons are switched off by the active form of the repressor |
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Term
When glucose is scarce
catabolite activator protein (CAP),
is activated by binding with
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Definition
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Term
Activated CAP attaches to the .... and increases the ...., thus accelerating .... |
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Definition
| promoter of the lac operon...affinity of RNA polymerase....transcription |
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Term
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Definition
| operons that encode enzymes used in catabolic pathways |
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Term
Differences between cell types result from |
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Definition
| differential gene expression |
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Term
| differential gene expression |
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Definition
•the expression of different genes by cells with the same genome
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Term
•Errors in gene expression can lead to
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Definition
| diseases including cancer |
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Term
Genes within highly packed ...... are usually not expressed |
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Definition
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Term
•Chemical modifications to histones and DNA of chromatin influence both ..... and...
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Definition
| chromatin structure.....gene expression |
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Term
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Definition
•acetyl groups are attached to positively charged lysines in histone tails
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Term
the process histone acetylation.....thereby |
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Definition
loosens chromatin structure....promoting the initiation of transcription |
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Term
The addition of ... can condense chromatin |
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Definition
| methyl groups (methylation) |
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Term
the addition of ... next to a .... can loosen chromatin |
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Definition
| phosphate groups (phosphorylation)....methylated amino acid.... |
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Term
•The histone code hypothesis proposes that
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Definition
| specific combinations of modifications help determine chromatin configuration and influence transcription |
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Term
•DNA methylation, the addition of methyl groups to certain bases in DNA, is associated
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Definition
| with reduced transcription in some species |
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Term
DNA methylation can cause |
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Definition
| long-term inactivation of genes in cellular differentiation |
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Term
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Definition
| methylation regulates expression of either the maternal or paternal alleles of certain genes at the start of development |
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Term
•The inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence is called
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Definition
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Term
•Chromatin-modifying enzymes provide
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Definition
| initial control of gene expression by making a region of DNA either more or less able to bind the transcription machinery |
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Term
Associated with most eukaryotic genes are |
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Definition
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Term
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Definition
•segments of noncoding DNA that help regulate transcription by binding certain proteins
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Term
Control elements and the proteins they bind are critical to the precise |
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Definition
| regulation of gene expression in different cell types |
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Term
To initiate transcription, eukaryotic RNA polymerase requires the assistance of proteins called |
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Definition
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Term
•General transcription factors are essential for the
|
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Definition
| transcription of all protein-coding genes |
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Term
•In eukaryotes, high levels of transcription of particular genes depend on
|
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Definition
| control elements interacting with specific transcription factors |
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Term
•Proximal control elements are located
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Definition
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Term
Distal control elements, groups of which are called |
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Definition
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Term
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Definition
| far away from a gene or even located in an intron |
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Term
An activator is a protein that |
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Definition
| binds to an enhancer and stimulates transcription of a gene |
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Term
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Definition
| mediator proteins to interact with proteins at the promoter |
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Term
Some transcription factors function as |
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Definition
•repressors, inhibiting expression of a particular gene
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Term
Some activators and repressors act indirectly by influencing |
|
Definition
| chromatin structure to promote or silence transcription |
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Term
•Each of the coordinately controlled eukaryotic genes has a
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Definition
| promoter and control elements |
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Term
•Copies of the activators recognize
|
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Definition
| specific control elements and promote simultaneous transcription of the genes |
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Term
eukaryotic genes
can be scattered over different chromosomes, but
|
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Definition
| each has the same combination of control elements |
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Term
•Regulatory mechanisms can operate at ....which allows
|
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Definition
| various stages after transcription ....a cell to fine-tune gene expression rapidly in response to environmental changes |
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Term
In alternative RNA splicing |
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Definition
different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns |
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Term
•The life span of mRNA molecules in the cytoplasm is a key to determining
|
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Definition
|
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Term
•The mRNA life span is determined in part by
|
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Definition
| sequences in the leader and trailer regions |
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Term
•The initiation of translation of selected
mRNAs can be blocked by
|
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Definition
| regulatory proteins that bind to sequences or structures of the mRNA |
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Term
translation of all mRNAs
in a cell may be regulated |
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Definition
|
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Term
•After translation, various types of .....including ... and the addition of che....., are subject to control
|
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Definition
| protein processing....cleavage....chemical groups |
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Term
|
Definition
| giant protein complexes that bind protein molecules and degrade them |
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Term
•Noncoding RNAs regulate gene expression at two points:
|
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Definition
| mRNA translation and chromatin configuration |
|
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Term
|
Definition
| small single-stranded RNA molecules that can bind to mRNA |
|
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Term
|
Definition
| degrade mRNA or block its translation |
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Term
•The phenomenon of inhibition of gene expression by RNA molecules is called
|
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Definition
|
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Term
|
Definition
| small interfering RNAs (siRNAs) |
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Term
siRNAs and miRNAs are similar BUT |
|
Definition
| form from different RNA precursors |
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Term
•siRNAs play a role in ....and can....
|
|
Definition
| heterochromatin formation...block large regions of the chromosome |
|
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Term
|
Definition
| block transcription of specific genes |
|
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Term
•Cell types are organized successively into
|
|
Definition
| tissues, organs, organ systems, and the whole organism |
|
|
Term
•The transformation from zygote to adult results from
|
|
Definition
| cell division, cell differentiation, and morphogenesis |
|
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Term
|
Definition
the
•process by which cells become specialized in structure and function
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Term
•The physical processes that give an organism its shape constitute
|
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Definition
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Term
Differential gene expression results from |
|
Definition
| genes being regulated differently in each cell type |
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Term
•An egg’s cytoplasm contains .... that are distributed unevenly in the unfertilized egg
|
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Definition
| RNA, proteins, and other substances |
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Term
•Cytoplasmic determinants are
|
|
Definition
| maternal substances in the egg that influence early development |
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Term
The other important source of developmental information is the.... especially signals from... nearby |
|
Definition
| environment around the cell... embryonic cells |
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Term
In the process called ..... signal molecules from embryonic cells cause transcriptional changes in nearby target cells |
|
Definition
|
|
Term
interactions between cells induce |
|
Definition
| differentiation of specialized cell types |
|
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Term
|
Definition
•a cell to its final fate
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Term
|
Definition
|
|
Term
•Cell differentiation is marked by the
|
|
Definition
| production of tissue-specific proteins |
|
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Term
|
Definition
| muscle-specific proteins and form skeletal muscle cells |
|
|
Term
•MyoD is one of several “master regulatory genes” that produce
|
|
Definition
| proteins that commit the cell to becoming skeletal muscle |
|
|
Term
The MyoD protein is a .... that |
|
Definition
| transcription factor...binds to enhancers of various target genes |
|
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Term
|
Definition
•the development of a spatial organization of tissues and organs
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Term
Positional information is |
|
Definition
the molecular cues that control pattern formation |
|
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Term
| Positional information tells a cell |
|
Definition
•its location relative to the body axes and to neighboring cells
|
|
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Term
|
Definition
•embryos with lethal mutations
|
|
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Term
Maternal effect genes encode for |
|
Definition
•cytoplasmic determinants that initially establish the axes of the body of Drosophila
|
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|
Term
These maternal effect genes are also called |
|
Definition
|
|
Term
egg-polarity genes control |
|
Definition
| orientation of the egg and consequently the fly |
|
|
Term
|
Definition
affects the front half of the body(the fruitfly?) |
|
|
Term
•gradients of substances called .....establish .....
|
|
Definition
| morphogens ....an embryo’s axes and other features |
|
|
Term
•The bicoid research is important for three reasons:
|
|
Definition
-It identified a specific protein required for some early steps in pattern formation
– It increased understanding of the mother’s role in embryo development
– It demonstrated a key developmental principle that a gradient of molecules can determine polarity and position in the embryo
|
|
|
Term
•The gene regulation systems that go wrong during cancer are the very same systems involved in
|
|
Definition
|
|
Term
|
Definition
| mutations to genes that regulate cell growth and division |
|
|
Term
•Tumor viruses can cause ....in
|
|
Definition
| cancer.... animals including humans |
|
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Term
|
Definition
|
|
Term
|
Definition
the corresponding normal cellular genes that are responsible for normal cell growth and division |
|
|
Term
•Conversion of a proto-oncogene to an oncogene can lead to
|
|
Definition
| abnormal stimulation of the cell cycle |
|
|
Term
Proto-oncogenes can be converted to oncogenes by |
|
Definition
–-Movement of DNA within the genome: if it ends up near an active promoter, transcription may increase
–-Amplification of a proto-oncogene: increases the number of copies of the gene
–-Point mutations in the proto-oncogene or its control elements: causes an increase in gene expression
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|
Term
Tumor-suppressor genes help |
|
Definition
•prevent uncontrolled cell growth
|
|
|
Term
•Mutations that decrease protein products of tumor-suppressor genes may
|
|
Definition
| contribute to cancer onset |
|
|
Term
What doTumor-suppressor proteins do? |
|
Definition
–-Repair damaged DNA
–- Control cell adhesion
–-Inhibit the cell cycle in the cell-signaling pathway
|
|
|
Term
•Multiple mutations are generally needed for
|
|
Definition
| full-fledged cancer; thus the incidence increases with age |
|
|
Term
•At the DNA level, a cancerous cell is usually characterized by at least
|
|
Definition
| one active oncogene and the mutation of several tumor-suppressor genes |
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