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What are the three functional types of RNA molecules? |
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Definition
1.Messenger RNA (mRNA) 2.Transfer RNA (tRNA) 3.Ribosomal RNA (rRNA) |
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Most genes encode proteins that are transcribed into what? |
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Definition
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The complete set of genetic info in a cell is referred to as what? |
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Definition
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the process of gene expression involves what two inter-related events? |
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Definition
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Term
the process copies the info encoded in DNA into RNA. |
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Definition
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Term
This process interprets info carried by RNA to synthesize the encoded protein. |
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Definition
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Term
A complex of enzymes and other proteins that synthesize DNA. (In an "assembly line") |
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Definition
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Term
This enzyme temporarily breaks the strands of DNA, relieving the tension caused by unwinding the 2 strands of the DNA helix. |
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Definition
DNA Gyrase (stops the gyrating of the DNA) |
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Term
This enzyme joins 2 DNA fragments by forming a covalent bond btwn the sugar and phosphate residues of adjacent nucleotides. |
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Definition
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Term
This enzyme synthesizes DNA. |
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Definition
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Term
What direction does synthesis always occur? |
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Definition
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Term
In DNA synthesis, nucleotides can only be added to what end of the existing fragment? |
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Definition
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Term
These enzymes unwind the DNA helix ahead of the replication fork. |
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Definition
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Term
Nucleic acid fragment produced during discontinuous synthesis of the lagging strand of DNA. |
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Definition
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Term
The distinct region of a DNA molecule at which replication is initiated. |
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Definition
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Enzyme that synthesizes small fragments of RNA to serve as primers for DNA synthesis. |
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Definition
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Term
A fragment of nucleic acid to which DNA polymerase can add nucleotides. (to an existing fragment only) |
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Definition
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Term
In transcription, this enzyme synthesizes single-stranded RNA molecules from a DNA template. |
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Definition
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Term
The DNA sequence to which RNA polymerase can bind and initiate transcription is called what? |
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Definition
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Term
A DNA sequence that stops the process of transcription. |
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Definition
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Term
What is one major difference btwn RNA polymerase and DNA polymerase? |
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Definition
RNA polymerase can start transcription without a primer. |
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Term
The DNA strand that serves as the template for transcription. |
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Definition
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Term
The complement of the minus strand |
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Definition
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Term
T or F, In prokaryotes, mRNA molecules can carry the info for one or multiple genes? |
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Definition
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Term
A transcript that carries one gene. |
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Definition
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Term
a transcript that carries multiple genes |
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Definition
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Term
This is a component of RNA polymerase that recognizes the promoter regions. A cell can have different types that recognize different promoters, allowing the cell to transcribe specialized sets of genes as needed. |
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Definition
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Term
These identify the regions of the DNA molecule that will be transcribed into RNA. They orient the direction of the RNA polymerase and dictate which strand will be used as the template. |
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Definition
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Term
What occurs in the elongation phase? |
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Definition
RNA polymerase moves along DNA using the (-) strand as a template to synthesize a single-stranded RNA molecule. |
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Term
Once elongation has proceeded far enough for RNA polymerase to clear the promoter, what can happen? |
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Definition
A new RNA enzyme can bind, thus a single gene can be transcribed repeatedly very quickly. |
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Term
What three structures are required for translation? |
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Definition
mRNA, ribosomes, and tRNA's. |
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Term
What direction does the ribosome move on the mRNA? |
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Definition
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Term
what are prokaryotic ribosomes composed of? |
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Definition
a 3OS subunit and a 5OS subunit each made up of a protein and ribosomal RNA. |
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Term
WHat are the two sites on a ribosome that tRNA can bind? What happens when they are both occupied by a tRNA? |
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Definition
The P-site and the A-site. When both are filled, an enzyme creates a peptide bond btwn the two amino acids. |
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Term
the site through which the initiating tRNA is released. |
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Definition
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Term
an assembly of multiple ribosomes attached to a single mRNA molecule. |
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Definition
polyribosome, or polysome |
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Term
Proteins that assist in the folding of polypeptides. |
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Definition
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Term
How can the cell tell if a polypeptide is destined for transport through the cytoplasmic membrane? |
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Definition
It will have a signal sequence which is a characteristic series of hydrophobic amino acids that tags them for transport. |
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Term
What are the four main differences btwn prok and euk gene expression? |
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Definition
Eukaryotic pre-mRNA must be processed. This involves capping, polyadenylation, and splicing. It must also be transferred out of the nucleus before it can be translated in the cytoplasm. Eukaryotic mRNA is monocystronic. |
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Term
This transmits information from outside the cell to the inside. |
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Definition
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Term
Some organisms can "sense" the density of cells within their own population. this is called what? |
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Definition
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Term
THis allows cells to activate genes that are only useful when expressed by a critical mass |
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Definition
quorum sensing (e.g. biofilms) |
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Term
an important mechanism that cells use to detect and react to changes in the external environment. |
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Definition
two-component regulatory system |
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Term
an alteration in the characteristics of certain surface proteins in a bacterial cell. |
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Definition
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Term
what allows pathogens to stay one step ahead of the body's defense by altering the molecules our immune systems recognize? |
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Definition
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Term
What is the routine switching on and off of certain genes? |
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Definition
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Term
A set of regulated genes transcribed as a single polycystronic message. |
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Definition
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Term
separate operons controlled by a single regulatory mechanism constitute a what? |
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Definition
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The simultaneous regulation of numerous genes is called what? |
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Definition
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Term
this type of enzymes are synthesized constantly; the genes that encode them are always active. (enzymes of glycolysis) |
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Definition
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Term
synthesis of this type of enzyme is turned on when needed. (Beta-galactoisade) |
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Definition
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Term
these enzymes are produced routinely, but their synthesis can be turned off when they are not required. (generally enzymes used in anabolic pathways) |
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Definition
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Term
when glucose is available, the lac operon is not expressed because of a phenom called what? |
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Definition
Carbon catabolite repression (CCR) |
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Term
The two-phase growth pattern between the use of glucose and other carbon /energy sources. |
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Definition
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Term
One mechanism of carbon catabolic repression involves an activator called _____ that is bound by an inducer cAMP. |
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Definition
CAP (catabolite activator protein) |
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Term
In the eukaryotic cell, this is routinely used to destroy specific RNA transcripts |
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Definition
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