modern applications of microbial genetics

Question 1

what is biotechnology

Answer 1

using living systems to benefit humankind, direct alteration of an organisms genetics to achieve desirable traits

Question 2

what does genetic engineering involve

Answer 2

the use of recombinant dna technology

Question 3

what is recombinant dna technology

Answer 3

the process where dna sequence is manipulated in vitro creating recombinant dna molecules that have new combinations of genetic material

Question 4

what is transgenic

Answer 4

when dna is entered into a different host species the host organisms is transgenic

Question 5

what is an example of transgenic bacteria

Answer 5

insulin from humans being inserted into a plasmid and then into bacteria allowing them to produce and secrete human insulin

Question 6

how do prokaryotes acquire foreign dna

Answer 6

conjugation
transduction
transformation

Question 7

what was the first molecular cloning

Answer 7

when cloned genes from the African clawed frog was inserted into bacterial plasmid that was then introduced to e coli

Question 8

what is molecular cloning

Answer 8

methods to construct recombinant dna and incorporate it into a host organism

Question 9

what are dna molecules manipulated with in recombinant dna

Answer 9

naturally occurring enzymes derived from bacteria viruses

Question 10

what makes recombinant dna possible

Answer 10

restriction endonuclease (restriction enzymes)

Question 11

what are restriction enzymes

Answer 11

bacterial enzymes produced as a protection mechanisms to cut and destroy foreign cytoplasmic dna mostly from bacteriophage infection

Question 12

how are restriction enzymes used

Answer 12

to cut dna fragments that can be spliced into another dna molecule to form recombinant molecules

Question 13

what is a recognition site

Answer 13

a specific usually palindromic dna sequence between four to six bace pairs

Question 14

what is a palindrome

Answer 14

a sequence of letters that reads the same forward as backwards, same sequences in the 5’-3’ to 3’-5’

Question 15

what does it mean to anneal

Answer 15

form hydrogen bonds between complementary bases at their sitcky ends

Question 16

what does annealing allow

Answer 16

hybridization of the single strand overhang

Question 17

why dont blunt ends attach as well as sticky ends

Answer 17

lack of complementary overhangs facilitating the process

Question 18

what is hybridization

Answer 18

joining together two complementary single strands of dna

Question 19

how are single strands rejoined

Answer 19

ligation, dna ligase rejoins the two-sugar phosphate backbones through covalent bonding

Question 20

what are plasmids

Answer 20

small pieces of double stranded dna that replicate independently of the bacterial chromosome

Question 21

what is a vector

Answer 21

dna molecules that carry dna fragments from one organism to another, usually plasmids

Question 22

what is a polylinker site

Answer 22

a short sequence containing multiple unique restriction enzyme recognition sites used for inserting dna into the plasmid after restriction digestion of dna and the plasmid

Question 23

what does having multiple restriction enzymes recognition sites within a polylinker do

Answer 23

makes plasmid vector versatile so it can be used for different cloning experiments with different restriction enzymes

Question 24

where is the polylinker site found

Answer 24

within the reporter gene

Question 25

what is the reporter gene

Answer 25

a gene sequence artificially engineered into the plasmid that encodes a protein that allows for visualization of dna insertion

Question 26

what does the reporter gene allow researchers to do

Answer 26

to distinguish host cells that contain recombinant plasmids with cloned dna fragments from host cells that only contain nonrecombinant plasmid vector

Question 27

what is the most common reporter gene

Answer 27

lacZ gene

Question 28

what does the lacZ gene encode

Answer 28

beta galactosidase

Question 29

what does beta galactosidase do

Answer 29

degrades lactose and synthetic analog x-gal

Question 30

what is shown on x-gal containing colonies

Answer 30

blue colonies

Question 31

when is the lacz gene disabled

Answer 31

when recombinant dna is spliced into the plasmid

Question 32

what is the most commonly used mechanism for introducing engineers plasmids into a bacterial cell

Answer 32

transformation

Question 33

what is transformation

Answer 33

when bacteria takes up free dna from their surrounding

Question 34

where does free bacteria come from in nature

Answer 34

lysed bacterial cells

Question 35

where does free dna come from in the lab

Answer 35

from recombinant plasmids introduced into the environment

Question 36

how is a cell made more competent

Answer 36

by increasing the permeability of the cell membrane

Question 37

how do you increase the permeability of the cell membrane

Answer 37

chemical treatments that neutralize charges on the cell membrane or exposing bacteria to an electric field that makes microscopic pores in the cell membrane

Question 38

come back to molecular cloning

Question 39

what is a genomic library

Answer 39

a complete copy of an organisms genome contained as recombinant dna plasmids engineered into unique clones of bacteria

Question 40

what is the purpose of a genomic library

Answer 40

allow researchers to creat large quantities of each fragment to determine sequence and function of any genes