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Biology 1002B Study Guide - Quiz Guide: Helicase, Ribosome, Prokaryote

Course Code
BIOL 1002B
Tom Haffie
Study Guide

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Overhang and Telomeres
-Overhang: Removal of last primer on lagging strand leaves unreplicated parental strand
-Overhang can not be replicated because new RNA primer cannot be inserted
-Overhang can be cut off causing DNA to be shortened after every replication
1. Overhang contains coding sequence→ Loses genetic information when cut off
2. Overhang is a sticky end and can stick to another strand with an overhang
-Changes the structure of other DNA strand and affect its functionality
-Solution: Buffers
-Telomeres (non-coding regions added to the end) acting as buffer
-Becomes sacrificed when DNA is replicated
-Reduced after every replication -Can be replenished (Depends on cell
-Run out = Losing coding sequence of DNA → Cell aging Senescence)
-Results in: Mutation/Apoptosis
-Folds on itself to form hair pin to prevent sticky end
-Length depends on cell type:
-Frequently dividing cell = Longer telomere
-Telomerase: Enzyme adds telomeres to overhang on 3’ end of lagging strand
-Brings RNA template:
-Portion of it matches overhang and binds to it
-Remainder portion adds DNA nucleotides to overhang on the 3’ end
-Added nucleotides complements RNA template
-Overhang is extended
-Primer is now able to be added
-DNA polymerase III bind and finishes replication
-Primer is removed leaving non-coding overhang
-Overhang folds to prevent sticky end
-Used to extract and replicate specific gene
-Not as efficient as PCR in producing copies of genes
-Gene only present in cell once→ Would require large amount of cells to work
-Genome extracted+segmented. Same sized portion removed from bacteria plasmids
-Genome inserted into plasmids and bacteria are cultured
-Resulting in many copies of the genome
-Tests made to isolate for bacteria containing gene of interest
-i.e. (eat resistant gene→ Treat with high temperature
-Gene isolated from bacteria
Restriction enzymes:
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