Term
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Definition
| How the environment determines certain genes that can be turned off or on |
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Term
| Griffith discovered... Which is... |
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Definition
| The transforming principle, properties from bacteria can transform other bacteria (conjugation) |
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Term
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Definition
| That transformation can occur in vitro |
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Term
| Avery MacLeod and McCarty discovered |
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Definition
| That DNA was behind transformation, as even with lipids, proteins and polysaccharides remaining, DNA still transformed cells |
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Term
| Hershey-Chase experiment demonstrated that |
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Definition
| the genetic material is transformation is DNA |
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Term
| Rosalind Franklins X-ray Chromatography of DNA showed |
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Definition
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Term
| The distance between base pairs of DNA is |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
Two carbon rings, Adenine and Guanine
One carbon ring, Cytosine, Thymine and Uracil |
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Term
Adenine nucleoside and nucleotide
Guanine nucleoside and nucleotide
Cytosine nucleoside and nucleotide
Thymine nucleoside and nucleotide
Uracil nucleoside and nucleotide |
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Definition
Adenosine, RNA = AMP, DNA = dAMP
Guanosine, RNA = GMP, DNA = dGMP
Cytidine, RNA = CMP, DNA =dCMP
Thymidine, RNA= N/A, DNA= dTMP
Uracidine, RNA= UMP, DNA= N/A |
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Term
| All DNA except for... is a right handed helix |
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Definition
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Term
| In single stranded DNA ... can form |
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Definition
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Term
| Semi-conservative replication |
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Definition
| Half the DNA is conserved in parent strand, half moves to daughter strand |
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Term
| Meselson and Stahl proved that... how? |
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Definition
| DNA replication was semi conservative, growing bacteria in heavy nitrogen, then moving them to normal nitrogen, and centrifuging them after each generation, mix between hybrid and light DNA |
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Term
| Each DNA strand has a.. end and a ...end |
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Definition
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Term
| A DNA strand can only be extended by adding nucleotides to the |
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Definition
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Term
| During DNA replication, replication from the 5' end is done by, and the results are called |
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Definition
| RNA primer, Okazaki fragments which are made by the RNA priming further up the strand, and moving towards the 5' end |
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Term
| The space between DNA fragments on the 5' end are removed with |
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Definition
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Term
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Definition
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Term
| Issue with replication DNA from the 5' end |
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Definition
| RNA primer can be removed but not replaced |
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Term
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Definition
| Adds extra sequence on 5' end so chromosomes are not shortened, active mostly in germ cells, not somatic cells |
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Term
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Definition
I-removes RNA primer and replaces with DNA, has a major role in repair of damaged DNA
II - restarts replication when blocked by damaged DNA
III-chromosome replication
IV&V-Allow replication to bypass DNA damage |
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Term
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Definition
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Term
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Definition
| keeps strands apart and prevents stem-loop formation |
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Term
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Definition
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Term
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Definition
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Term
| In mammals RNA primers are removed by |
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Definition
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Term
| During DNA replication, DNA can become |
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Definition
| over or undercoiled, topoisomerase and gyrase restore the balance |
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Term
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Definition
Relaxes overcoiled DNA
Rewinds unwound DNA |
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Term
| DNA takes about ... to replicate and it takes another... |
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Definition
| 40minutes, 20 to form a septum so the cell can divide |
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Term
| Why can E.coli replicate faster than DNA? |
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Definition
| The next set of DNA starts replicating before the first cell divides |
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Term
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Definition
| Bacterial equivalent of nucleus |
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Term
| Genes clustered together with several genes transcribed from one promoter |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| protect the 5' end from degredation, interact with translation factors to recruit ribosomes, |
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Term
| At the 3' end of the RNA, transcription |
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Definition
| goes past the end of the mRNA, the extra is later cut off |
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Term
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Definition
| discovered that deletion of a nucleotide could abolish gene function |
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Term
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Definition
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Term
| An extra frameshift mutations |
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Definition
| may restore gene function |
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Term
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Definition
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Term
| Transfer RNA has a ... which is... long |
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Definition
| variant arm, 3-21 variants long |
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Term
| Aminoacylation is catalysed by 1 enzyme, in 2 steps |
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Definition
| The aminoacid is activated, and then reacts with tRNA to form aa-tRNA |
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Term
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Definition
Class I-larger and more hydrophobic, more structural, must recognise to aminoacylate their cognate tRNAs and aminoacylate their tRNAs terminal -OH group
Class II do not interact with the tRNAs anticodonand charge 3-Oh |
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Term
| tRNA can bind to more than one codon thanks to |
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Definition
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Term
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Definition
Bind mRNA so codons can be read
Includes binding site for tRNA molecules
promotes polypeptide chain elongation, initiation and termination
catalyse peptide bond formation
allows translation of sequential codons |
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Term
| Ribosomes have...tRNA binding sites |
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Definition
| 3, the Asite, accomadates incoming aatRNA, the P site, which accomadates the tRNA attached to the growing chain, and the E site, which accomadates the tRNA without the aminoacid, which is leaving |
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Term
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Definition
| 40% bigger than bacterial versions |
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Term
| tRNAs on the ... sites interact closely with.... because of... |
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Definition
| A&P, mRNA via base pairing, acceptor ends are close together |
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Term
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Definition
| initaition, elongation, termination |
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Term
| what are required as energy sources for translation |
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Definition
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Term
| Prokaryotic mRNAs have more than |
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Definition
| one coding region (polycistronic), each coding region has its own initiation and termination codons |
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Term
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Definition
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Term
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Definition
| because of the length of mRNAs more than one ribosome can translate a message |
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Term
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Definition
| 2 ribosomal subunits, mRNA to be translated, aatRNA specified by the 1st codon, GTP, Initiation factors |
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Term
| Ribosomes recognise the start codon by |
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Definition
| the Shine-Dalgaro sequence, binds with 16S rRNA of 30S subunit, only in prokaryotes, in eukaryotes, the initiating codon is recognised by special tRNA, and facilitatedby GTP, a large subunit then joins the complex |
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Term
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Definition
| Involves the addition of amino acids to the carboxyl end of the growing chain |
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Term
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Definition
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Term
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Definition
| Restriction factors binding and causing hydrolysis of the bond linking peptide to tRNA in the P site |
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Term
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Definition
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Term
| Streptomtycin blocks translation by |
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Definition
| causing the ribosome to misread pyrimidines |
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Term
| Chloramphenicol blocks translation by |
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Definition
| inhibiting peptidyltranferase activity, it binds near the a site |
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Term
| Tetracycline blocks translation by |
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Definition
| Binding to the small subunit and preventing entry of aatRNA |
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Term
| Ricin blocks translation by |
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Definition
| inactivating the large eukaryotic ribosome, and hydrolytically removing adenine base |
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Term
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Definition
| If a polypeptide chain is still attached to the ribosome when it is modified |
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Term
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Definition
| if a polypeptide chain is modified after being disconnected from the ribosome |
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Term
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Definition
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Term
| What catalyses phosphorylation |
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Definition
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Term
| phosphorylation can occur on |
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Definition
| hydroxyl groups of serine, threonine and tyrosine |
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Term
| When proteins are no longer useful |
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Definition
| they are ubiquinated, a 76-residue protein ubiquitin is added, and a protein signal for degredation is sent |
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Term
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Definition
| GTP translation is inhibited, GTP hydrolysis is stimulated and dissacociation of the protein from the ribosome is stimulated |
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Term
| When signal peptidase enters the lumen |
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Definition
| it cleaves signal peptides |
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Term
| The definition of mutation |
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Definition
| any alteration to the genetic material (DNA or RNA) that produces a heritable change in the nucleotide sequence |
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Term
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Definition
| the standard form of a gene or organism |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| redistributing of genetic material between non-homologous chromosomes |
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Term
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Definition
| Changes in chromosome number |
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Term
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Definition
| Movement of a piece of DNA from location to another |
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Term
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Definition
| purine -> purine or pyramidine -> pyramidine |
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Term
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Definition
| purine -> pyramidine or vice versa |
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Term
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Definition
| An alteration to the chemical structure of one of the components of DNA |
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Term
| How many lesions per cell per day |
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Definition
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Term
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Definition
| adducts, nicks, mismatches |
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Term
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Definition
| replicated adduct, chromosome break, cross link |
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Term
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Definition
| is repaired by another molecule taking up the methyl group -> direct repair |
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Term
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Definition
| removal and resynthesis of a damaged DNA segment |
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Term
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Definition
| The entire genetic content of an organism |
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Term
| Humans have around.... genes |
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Definition
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Term
| Most bacteria have ... chromosome(s) |
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Definition
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Term
| Even in simple eukaryotes genomes comprise... chromosomes |
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Definition
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Term
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Definition
| Circular, one origin of replication, no ends to replicate, chromosomes seperate by membrane association |
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Term
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Definition
| Linear, Multiple origins of replication, ends protected by telomeres, chromosomes seperated by pulling centromeres apart |
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Term
| Operons in bacteria allow |
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Definition
| two or more genes to be transcribed from the same promoter, and overlap of stop/start codons |
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Term
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Definition
| When expressed, cuts the DNA at the ends of the terminal repeats and moves the transposon to a new, random site |
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Term
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Definition
| non-essential genes, such as antimetabolites, new metabolic activities |
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Term
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Definition
| col/kil occurs when the bacteria come under stress, 1/1000 cells carrying the ColE1 plasmid express the kil protein, causing the cell to die, and release colicin, which kills all other cells which dont have the colE1 gene |
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Term
| Donor cells are and recipient cells are |
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Definition
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Term
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Definition
| Propagation in vivo of multiple identical copies of genes for study, manipulation or another application |
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Term
DNA ligase
DNA polymerase
Reverse transcriptase
Restriction endonuclease |
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Definition
Joins DNA molecules
Fills gaps in duplexes by stepwise addition
Makes a DNA copy of an RNA molecule
Cleaves DNA at specific base sequences |
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Term
| Restriction modification systems |
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Definition
| protect against phages by cutting DNA at specific sites, which are modified in the host DNA to be protected |
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Term
| DNA can not be cleaved if it is |
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Definition
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Term
| Type I, II and III restriction enzymes |
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Definition
| I cuts 1000bp from site, II cuts at site, III cuts next to site |
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Term
| Basic features of a phage |
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Definition
| Head, neck and collar, core, sheath, end plate. fibres |
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Term
| cDNA library versus genomic library |
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Definition
| mRNA/protein coding reagion ->cDNA, intergenic regions and introns -> genomic library |
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Term
| DNA probes are designed for |
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Definition
| the least degenerate region |
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Term
| How is the amount of DNA measured |
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Definition
| analysing cell nuclei, e.g. DNA-specific stains |
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Term
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Definition
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Term
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Definition
| constant value, it is haploid |
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Term
| Why is there so much non-coding DNA in multicelled eukaryotes |
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Definition
| Introns, genes for non-coding RNAs, non-gene DNA (often highly repeated) |
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Term
| How much of human DNA is coding genic? |
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Definition
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Term
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Definition
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Term
| Alternative splicing requires |
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Definition
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Term
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Definition
| fragments of DNA that can insert into new chromosomal locations |
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Term
| Two types of transposable elements |
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Definition
via DNA - transposons
via RNA - retrotransposons |
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Term
| Transposable elements need |
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Definition
| transposase or reverse transcriptase |
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Term
| Why do transposable elements multiply? |
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Definition
| Occur after replication of TE, but before target site, causing original site to be repaired and TE to multiply |
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Term
| Tandem repeat DNA is often found at |
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Definition
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Term
| DNA probes are designed for |
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Definition
| the least degenerate region |
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Term
| How is the amount of DNA measured |
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Definition
| analysing cell nuclei, e.g. DNA-specific stains |
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Term
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Definition
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Term
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Definition
| constant value, it is haploid |
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Term
| Why is there so much non-coding DNA in multicelled eukaryotes |
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Definition
| Introns, genes for non-coding RNAs, non-gene DNA (often highly repeated) |
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Term
| How much of human DNA is coding genic? |
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Definition
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Term
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Definition
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Term
| Alternative splicing requires |
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Definition
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Term
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Definition
| fragments of DNA that can insert into new chromosomal locations |
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Term
| Two types of transposable elements |
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Definition
via DNA - transposons
via RNA - retrotransposons |
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Term
| Transposable elements need |
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Definition
| transposase or reverse transcriptase |
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Term
| Why do transposable elements multiply? |
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Definition
| Occur after replication of TE, but before target site, causing original site to be repaired and TE to multiply |
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Term
| Tandem repeat DNA is often found at |
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Definition
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Term
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Definition
| DNA that has a different density to the rest of the chromosomal DNA because the base composition differs significantly from the average |
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Term
| Satellite DNA is often found at |
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Definition
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Term
| rDNA genes are transcribed in |
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Definition
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Term
| Satellite DNA must have more than... anything less than this is a |
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Definition
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Term
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Definition
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Term
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Definition
| centromeres, telomeres and rDNA |
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Term
Acute control
Chronic control |
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Definition
changes to specific activity, hours and below
changes to enzyme amount, hours and above |
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Term
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Definition
| irreversible, rate limiting steps |
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Term
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Definition
| regulated by positive and negative effectors, effectors bind to somewhere other than the catalytic site of that subunit |
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Term
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Definition
| important allosteric regulators |
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Term
| proteins that are zymogens |
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Definition
fibrin -> cleaved by plasmin
plasminogen -> cleaved by tissue plasminogen activator to form plasmin |
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Term
| regulatory proteins ofter have... and thus a... |
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Definition
| high rates of turnover, short half-lives |
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Term
| Proteins are tagged for degredation by |
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Definition
| ubiquitin, and then broken down by proteases |
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Term
Endocrine
Paracrine
Juxtacrine
Synaptic |
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Definition
Hormones
Local chemical mediators
cell to cell contact
Neurone cells |
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Term
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Definition
| Steroid, can cross plasma membrane, receptor in cytoplasm or nucleus |
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Term
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Definition
| Receptor in plasma membrane, cannot cross membrane |
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Term
| Two forms of signal transduction |
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Definition
Interaction with effectors increases conc of a second messenger
Recruits catalysts |
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Term
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Definition
| causes enzyme cascade, when one enzyme activates another |
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Term
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Definition
| feedback results in receptor being shut off |
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Term
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Definition
| G-protein coupled receptors, second messengers, activated by hormone binding, in turn it activates a g protein, which releases a subunit which activates an effector enzyme, which produces a second messenger |
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Term
| Two main secondary messengers |
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Definition
cyclic AMP, activates protein kinase A, generated if a ligand binds to a receptor
inositol tris phosphate, generated in response to ligand binding to receptor, increase Ca2+ conc |
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Term
| FOR Gproteins, what follows ligand binding to receptor |
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Definition
| G protein binds to receptor, G alpha releases GDP and binds to GTP, G alpha dissacoiates from betagamma, and binds to effector |
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Term
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Definition
Phosphorylates a range of proteins, can activate or inactivate them, determines cell response to hormone
Can cause enzyme cascades |
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Term
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Definition
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Term
| Ligands which increase cAMP |
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Definition
| Glucagon, Adrenaline if beta receptors, vasopressin, thyroptropin |
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Term
| Ligands which decrease cAMP |
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Definition
| Adrenaline if alpha receptors, adenosine |
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Term
| Ca2+ as a secondary messenger |
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Definition
| hormone binding activates a g-protein, which activates a phospholipase C, which releases inositol tris phosphate and diacylglycerol |
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Term
| Ligands which act through IP3 (inositol tris phosphate) or Ca2+ |
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Definition
Vasopressin
Acetylcholine
Antigens
Thrombin |
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Term
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Definition
| control other genes by binding to target DNA sites |
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Term
| Positive and negative gene control |
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Definition
Negative: a repressor binds to a cis acting operator to prevent transcription
Positive: An activator binds to a cis-acting site to allow transcription |
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Term
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Definition
| Inductible gene - gene for an enzyme is induced by appearance of the enzymes substrate |
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Term
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Definition
| Gene for an enzyme is repressed by the product of the enzyme |
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Term
| Four patterns of gene control |
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Definition
Negative inducible, Negative repressible
Positive inducible, positive repressible |
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Term
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Definition
| Dual control of a gene, Transcription controlled via translation |
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Term
| Transcription factors need |
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Definition
| Chromatin to change state in order to activate a gene |
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Term
| Activators are controlled by |
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Definition
Covalent modification
Dimerisation
Sequesration
Cleavage |
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Term
| Chromatin is opened up for transcription factors to bind by |
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Definition
| a remodelling complex and activator |
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Term
| Proto-oncogenes can become oncogenes through |
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Definition
Mutation
Gene Amplification
Chromosome rearrangement |
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Term
| Tumour supressor genes are inactivated by |
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Definition
Non disjunction
Chromosome losss then duplication
mitotic recombination
gene conversion
deletion
point mutation |
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