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;
22 Cards in this Set
- Front
- Back
|
Restriction Digestion?
|
process of cutting DNA molecules into smaller pieces with enzymes called Restriction Endonucleases
|
|
|
What does restriction enzymes recognize?
|
4-6 base palindromic sequence
|
|
|
Restriction site?
|
actual sequence of DNA where a restriction endonuclease cuts
|
|
|
Where do restriction endonucleases come from?
|
purified from prokaryotes
|
|
|
Function of restriction enzymes?
|
destroy foreign DNA
|
|
|
Role of methylation?
|
allows bacteria to protect their own DNA while cutting up foreign DNA
|
|
|
2 types of fragments?
|
sticky ends
blunt ends |
|
|
Sticky ends?
|
short length of unpaired nucleotide bases
|
|
|
Blunt ends?
|
double stranded DNA framgent
|
|
|
Types of Restriction digestion?
|
complete digestion
partial digestion |
|
|
When does partial digestion occur? 3
|
if less enzyme is used
reaction is stopped before required time wrong buffer is used |
|
|
How many DNA fragments will be produced in circular DNA with one restriction site?
|
one
|
|
|
How many DNA fragments will be produced in linear DNA with one restriction site?
|
2
|
|
|
How many DNA fragments will be produced in circular DNA with 2 restriction sites?
|
2
|
|
|
How many DNA fragments will be produced in linear DNA with 2 restriction sites?
|
3
|
|
|
What happens during Electrophoresis loading? 2
|
-DNA has a strong negative charge at neutral pH
-electric current carries negatively charged DNA through gel towards positive electrode |
|
|
What happens during Electrophoresis running?
|
agarose gel sieves DNA fragment according to fragment size and shape
|
|
|
Why do you add a loading dye in a DNA sample? 3
|
loading dye in heavier that causes the DNA solution to sink
-act as a marker -makes it easier to see the sample that is being loaded |
|
|
Function of Ethedium bromide in a gel?
|
-fluorescent dye used to visualize DNA bands on a trans-illuminator
|
|
|
Smearing?
|
DNA appears as a messy continuous band rather than independent, discreet bands
|
|
|
When can smearing occur?
|
-contamination of some stray nuclease that degarde the DNA into dozens
-use of wrong buffer, wrong temp. and wrong conditions |
|
|
Restriction map?
|
physical map of DNA showing recognition sites of specific restriction endonucleases
|
