Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
|
Restriction Enzymes
|
Identified in bacteria where they are used as a mechanism in one strain/species of bacterium to prevent the invasion of DNA from another bacterium
|
|
|
How does bacterium prevent its own DNA from being cut?
|
methylation of DNA
|
|
|
How are restriction enzymes named?
|
according to their bacterial origins
|
|
|
RE recognition/cleavage sites are...
|
palindromic DNA sequences, TCATGA, flipped and opposite
|
|
|
What is probability a particular RE recognition site would occur by change within a piece of DNA?
|
1/4 to exponent of how many bp are in the site
|
|
|
Three Different types of DNA ends
|
Blunt Ends
5' Overhang 3' Overhang |
|
|
5' Overhang and 3' Overhang
|
staggard ends, sticky ends, available for base pairing
|
|
|
Blunt Ends
|
no additional bade pairing involved
|
|
|
DNA cloning
|
compatible ends are required in order to join the two pieces together
|
|
|
Uses for RE maps
|
1. Provide information about the similarities of genes/DNAs from different organisms
2. Provide Information for further analyses of the DNA molecule |
|
|
The Central Dogma
|
-all cells follow this basic genetic pathway except retroviruses and prions
-DNA is for permanent storage of genetic information -RNA is for transient storage of genetic information (except for structural and catalytic RNA) -Protein is the final gene product |
|
|
Transcription produces...
|
RNA that is complimentary to one strand of DNA
|
|
|
RNA has same sequence as which strand?
|
coding strand
|
|
|
mRNA
|
messenger RNAs, code for proteins, only 3-5% of total RNA in cell
|
|
|
rRNA
|
ribosomal RNAs, form the basic structure of the ribosome and catalyze protein synthesis, majority of RNA in cell (75-80%)
|
|
|
snRNA
|
small nuclear RNAs involved in a variety of nuclear processes including pre-mRNA splicing, this along with snoRNAs and other non-coding RNAs make up less than 5% in cell
|
|
|
snoRNA
|
small nuclear RNAs, used to process and chemically modify rRNAs
|
|
|
other non-coding RNAs
|
diverse cellular processes, including telomere synthesis, X-chromosome inactivation, and transport of proteins into the ER
|
|
|
Why different types of Omega but only one type of core enzyme?
|
different omegas used to recognize different promoters
|
|
|
What is a promoter?
|
a region that tells RNA polymerase where to sit on the DNA to start transcription
|
|
|
how are genes transcribed with different efficiencies?
|
number of starts
|
|
|
Three main phases of transcription of bacterial RNA polymerase
|
initiation
elongation termination |
|
|
Initiation Phase
|
RNA pol unwinds DNA at promoter, RNA pol synthesizes short piece of RNA at relatively low efficiency
|
|
|
Elongation Phase
|
RNA exits through a channel that is formed by closing the flap at back of RNA pol
3 conformational changes - Jaws of RNA pol clamps more tightly to DNA, closing of the flap at back, omega factor dissociates |
|
|
Termination Phase
|
Hairpin structure formed in the RNA corresponding to the DNA termination sequence causes the RNA pol to release its hold on the RNA
|
|
|
Bacterial transcription terminators
|
on DNA - consists of two-fold symmetrical DNA sequences followed by a string of AT repeats
on transcribed RNA - formation of stem-loop (hairpin) structure followed by a string of AU repeats |
|
|
Which has single type of RNA pol?
|
prokaryotes
|
|
|
Which has 3 types of RNA polymerases?
|
Eukaryotes
|
|
|
One difference between eukaryotic and prokaryotic RNA pol
|
Eukaryotic RNA pol requires the presence of additional initiation proteins (transcription factors) before they can bind selectively to different promoter sequences
|
