micro lab 2 practice questions

Question 1

What is an electropherogram?

Answer 1

4 color record of the DNA sequence generated by electrophoresis.

A= green
G=Black
C=Blue
T=red

Question 2

What does NCBI stand for?

Answer 2

National center biotechnology Information

Question 3

what does BLAST stand for?

Answer 3

Biotechnology Local Alignment Search Tool

Question 4

Why are antibiotics ineffective against viruses?

Answer 4

Because viruses don’t have enzymatic pathways, cell wall, membrane or nucleic acid synthesis

Question 5

Describe 2 ways in which antibiotics affect bacteria

Answer 5

Sulfa drugs- inhibition of enzymatic pathways

Penicillin, Bacitracin- inhibition of cell wall synthesis

Question 6

burst size

Answer 6

is the number of virions that are released from 1 infected cell

Question 7

burst time

Answer 7

is the length of time from the attachment to release.

Question 8

What does the bla marker gene code for?

Answer 8

bla codes for b-lactmase enzymes that destroy b-lactam antibiotics (ampicillin, penicillin)

Question 9

what is the Arabinose for?

Answer 9

it helps determine if transformation was successful and would help it grow evenly through cytolytic transformation.

Question 10

competent cell

Answer 10

a competent cell is a cell that can be transformed. not all cells are naturally competent.

Question 11

how did we make e.coli competent?

Answer 11

1. grow to mid-log phase–> temporary holes in cell wall
2. put in ice–? slows metabolism & stays in mid log
3. CaCl2–> neutralize cell surface charge so it doesnt repel DNA
4. heat shock–> cells produce surface proteins that somehow help them take up DNA

Question 12

what is a loading dye?

Answer 12

this dye is called a loading dye or a tracking dye due to 2 distinct function. It is a mix of acidic (anion is colored) and sucrose; added to DNA sample before loading onto gel.

• sucrose makes the sample heavy to sink in the well
• does not bind to the DNA, but will move in the same direction as DNA.

Question 13

loading dye contains:

Answer 13

xlene cyanol: moves slowly, like DNA 3-4KB

bromphenol purple: moves quickly, like DNA 100-300bp

Question 14

what is gel red used for?

Answer 14

this dye is added to the gel and ill stick to the DNA, glows in the UV light or blue light so that DNA fragments can b e visible.

Question 15

what is DNA ladder used for?

Answer 15

DNA ladder is a mix of DNA fragments of known sizes, loaded onto its own well & used as a size standard. the ladder we used in class is lambda hindIII

Question 16

what is a RFLP

Answer 16

Restriction fragment length polymorphism:
a patten of DNA fragments that results when you cut a specific piece of DNA with a specific restriction enzyme and subjecting the resulting fragments to gel electrophoresis and will created a pattern known as DNA fingerprint or RFLP

Question 17

What does PCR stand for?

Answer 17

polymerase chain reaction

Question 18

what is PCR used for?

Answer 18

PCR is used to make tons of copies of the rDNA gene from unknown. allows for segments of DNA to be amplified, replicated over and over again. DNA replication modified to work outside of the cell