Molecular Genetics Flashcards

Question

Post Transcriptional control

Answer 1

Modifications to pre-mRNA affect life/use of RNA in cytoplasm

Answer 2

Proteins activated through processing | Signals enlist cell machinery to destroy proteins

Answer 3

Responds to presence/absence of lactose and glucose

Answer 4

Produces enzymes needed to digest lactose

Answer 5

fast/slow switch

Answer 6

on/off switch

Answer 7

binds to operator and prevents RNA polyermase from binding When lactose is present it binds to represser, changes 3D shape and repressor removed from operator

Answer 8

Detects glucose levels

Answer 9

cAMP binds to CAp, together they bind to DNA ahead of promoter to help RNAP bind cAMP activated CAP proteins stimulate transcription of 100+genes including lac operon RNAP can still work without cAMP-CAP complex but is less likely to bind therefore slower

Answer 10

Silent-Doesn't change a.a. b/c codes for same a.m Mis-sense- Incorrect a.a, can cause malfunctioning protein Non-sense- Codes for stop a.a, shortens protein

Answer 11

Insertion- nucleotide inserted | Deletion- nucleotide deleted

Answer 12

Deletion- removes chromosomal segment Duplication- repeats a segment Inversion- reverses a segment within chromosome Translocation-one segment from one chromosome moved to another

Answer 13

Telomere- molecular cap (repeating TTAGG) that shortens with every division b/c cells cant replicate it easily Once too short, gene p53 stops cell replication Telomerase rebuilds telomere, allows cell to keep dividing

Answer 14

Investigated composition of DNA using pus cells | Discovered nuclei of cells contained large quantities of substance unlike proteins (named nuclein)

Answer 15

Discovered that cells with nucleus removed could not regenerate but cells with nucleus but other part removed could

Answer 16

Injected mice with encapsulated and uncapsulated pneumonia cells epacsulated= death uncapsulated= alive

Answer 17

Ruptured heat killed encapsulated cells to release contents tested RNA, DNA, protein coats for transforming activity Result- DNA is transforming principle, not proteins

Answer 18

Virus has 2 parts (DNA, Protein coat), only DNA enters bacteria when infecting, not protein coat

Answer 19

enzyme that is able to cleave double stranded DNA into fragments at specific sequences

Answer 20

end of DNA fragment w/o complimentary base (has overhang) | -Easier to connect

Answer 21

DNA fragment with complimentary base (no overhang)

Answer 22

-Polymerase Chain Reaction -direct method of making copies of a desired DNA sequence easily (doesn't have to be inserted into a plasmid) -

Answer 23

- Heat breaks DNA into 2 strandes - Temperature lowered - DNA primers replace RNA primers - Taq polymerase adds complimentary nucleotides - Process repeats

Answer 24

- Separates DNA fragments by size - solution containing DNA fragments is placed in a well in the gel, which is a rectangular or square slab that contains electrolytes. A negative charge is placed at one end of the gel (where the wells are) and a positive charge is placed at the other end of the gel. The negatively charged DNA moves towards to positive charge. The smaller fragments move faster than the larger fragments, creating separation

Answer 25

5. A gene can be cloned into a plasmid when a gene fragment that was cut by the same restriction enzyme that cut a plasmid joins with the plasmid fragment. DNA ligase reforms the phosphodiester bond between the fragments, and the plasmid as circular again and contains the foreign gene fragment. When the plasmid replicates, each copy will contain both the plasmid fragment and the foreign gene fragment, therefore, the gene has been cloned.