Biosci101 Genetics And Dna Technology

Front 1

What is recombinant DNA?

Back 1

genes or DNA from 2 different sources combined in vitro into same molecule

Front 2

What are the 2 general parts of a gene?

Back 2

1.promotor at 5'end of coding strand

2. coding region

Front 3

What is the purpose/structure of the promoter region?

Back 3

controls transcription of mRNA, host specific and has protein binding sites for transcription factors

Front 4

What is the purpose/structure of the coding region?

Back 4

exons and (in euk) introns, containing triplet codes for an amino acid.

start and stop codons at either end of coding region

Front 5

What is biotechnology?

Back 5

manipulation of organisms or their components to make useful products

Front 6

What is genetic engineering?

Back 6

in vitro alteration or recombination of genetic material and reintroduction of altered material into living organisms

Front 7

What is the key difference between biotech and genetic engineering?

Back 7

genetic engineering has an in vitro step

Front 8

What are the benefits of genetic engineering?

Back 8

1. precise choice of genes

2. genes from any species

3. control of gene expression

Front 9

What are the negatives of selective breeding?

Back 9

new combinations of many genes

only genes from related species

no control

Front 10

How are genes cloned into a plasmid?

Back 10

1. treat plasmids with a restriction enzyme that cuts DNA ring at a single restriction site

2. foreign DNA is cut with same restriction enzyme

3. insert DNA ligated into plasmid to form recombinant plasmid

4. bacterial cells transformed with modified plasmid

Front 11

What are restriction enzymes? How are they gathered?

Back 11

cutsDNA at specific sequences (4-6 bp long)

isolated from bacteria (where they protect against phages)

Front 12

What are palindromic sequences?

Back 12

base pair sequences that read the same forwards as backwards

Front 13

Are most restriction sites symmetrical or asymmetrical? How does this affect cleavage?

Back 13

symmetrical; cleave DNA in a staggered way`

Front 14

What are sticky ends?

Back 14

single-stranded ends at each side of restriction site, result from staggered cleavage

Front 15

How is DNA ligase involved in the formation of the recombinant plasmid?

Back 15

covalently links the two pieces of DNA together after the sticky ends hydrogen bond in place, and catalyses formation of covalent bonds between sugar-phosphate backbones

Front 16

What is a cloning vector?

Back 16

a DNA molecule that can carry foreign DNA

Front 17

What is a plasmid?

Back 17

a circular piece of DNA which can autonomously replicate within bacteria and can easily be isolated and inserted with foreign DNA

Front 18

What is a BAC vector? How large of DNA fragments can they hold?

Back 18

plasmids constructed with replication origin of E. coli F factor

up to 300 kb

Front 19

What type of bacteria is usually used as a host cell? Why?

Back 19

E. coli

easily grown and easily transformed

large number of vectors

DNA isolation and transformation procedures well established

Front 20

How is transformation of the bacteria induced?

Back 20

bacterial cells treated to make them competent, usually with calcium and heat shock treatment, or electroporation

Front 21

What are the two types of selectable markers?

Back 21

markers used to make sure bacterium have taken up a plasmid (eg antiobiotic resistance gene) or

markers to ensure plasmid has the insert gene (eg. marker that chages colour of bacterial colony on certain plates (lac Z gene))

Front 22

What does PCR stand for

Back 22

polymerase chain reaction

Front 23

What are the three steps of PCR?

Back 23

Denaturation

Annealing

Elongation

Front 24

What enzyme is PCR based on?

Back 24

heat stable polymerase (DNA Polymerase)

Front 25

What else is required to complete PCR?

Back 25

an RNA primer (as DNA polymerase needs existing strand to add to)

Front 26

What are the reagents in a PCR reaction?

Back 26

1. DNA polymerase

2. dexoyribonucleotides (dNTPs)

3. two primers (one per strand)

Front 27

What happens during denaturation?

Back 27

DNA heated to 95 degrees C, causing hydrogen bonds to break and two single strands to form

Front 28

What happens during Annealing?

Back 28

temperature reduced to 55 degrees C to allow primers to bind

Front 29

What happens during extension?

Back 29

temperature increased to 72 degrees C, DNA polymerase extends complementary strands to form 2 new molecules

Front 30

How many DNA molecules are produced from this process?

Back 30

2^n where n= number of cycles

Front 31

At what point does PCR produce specifically the target sequence?

Back 31

after the 3rd sequence

Front 32

What does gel electrophoresis do?

Back 32

separate macromolecules based on rate of movement through gel in an electrical field

Front 33

What is the rate of movement dependent on?

Back 33

size, electric charge, and other physical properties

Front 34

What are size markers used for in gel electrophoresis?

Back 34

calibration (show relative length of DNA at that point)

Front 35

What charge does DNA have?

Back 35

negative charge

Front 36

What is a genome?

Back 36

total compliment of DNA that makes up the inherited genetic materials of an organism

Front 37

What is a transcriptome?

Back 37

part of the genome that is transcribed into RNA (particularly mRNA)

Front 38

What is the "central dogma"?

Back 38

genome -> transcriptome ->proteome

Front 39

What does DNA sequencing do?

Back 39

reveals order of nucleotides along DNA strand

Front 40

What is the dideoxy chain termination method?

Back 40

synthesis of a complimentary strand of DNA to that being sequenced is teriminated in some of the molecules being synthesised by addition of a fluorescently tagged di-deoxyribonucleotide

Front 41

What is di-deoxy chain termination also called?

Back 41

asymmetric PCR