Chapter 9 Flashcards Preview

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Flashcards in Chapter 9 Deck (60):
1

Anticodon

*

the three nucleotides by which a tRNA recognizes an mRNA codon.

2

Bacteriophages

*

Viruses that infect bacterial cells.

3

cDNA

What is it?

How is it made?

Why is it used in biotechnology?

*

Complementary DNA:

The reverse of the normal DNA--> RNA process.

A DNA copy of mRNA is produced by a reverse transcriptase, then the mRNA is enzymatically digested away. DNA polymerase then synthesizes a complementary strand of DNA, creating a double strand  of DNA containing information from the mRNA.

This DNA does not contain introns and is suitable for expression in prokaryotic cells.

4

Codon

How many?

Types?

*

A sequence of three nucleotides in mRNA that specifies the insertion of an amino acid into a polypeptide.

The genetic code contains 64 codons.

61 sense codons code for amino acids

3 nonsense codons code for stops

1 start codon AUG

5

DNA Fingerprinting

How does it work?

*

Analysis of DNA restriction fragments by electrophoresis.

DNA from different organisms are cut with the same restriction enzyme.

The fragments are separated by agarose gel electrophoresis.

The fragment sizes are compared.

Matching patterns indicate the same organism.

6

DNA Polymerase

*

An enzyme that synthesizes  DNA by copying a

DNA template.

7

Electroporation

*

DNA method of inserting DNA into a cell that does not use a vector

Uses an electrical current to form microscopic pores in the membrane of cells.

DNA then enters then cells through the pores.

8

Exon

*

Stretches of DNA that code for a protein.  These stretches are spliced together after introns are removed.

9

Gene replacement therapy

*

The treatment of a genetic disease by replacing abnormal genes.

10

Endonucleases

*

An important enzyme in DNA repair:

Cut DNA backbone in a strand of DNA; facilitates repair and insertions.

11

Agarose Gel Electrophesis

What is it used for?

*

The separation of substances(such as serum proteins or DNA) by their rate of movement through an electrical field.

Smaller fragments move faster and larger fragments move slower.

DNA fingerprinting

12

Genetic Code

*

The mRNA codons and the amino acids they encode.

13

                              genetic engineering

4 Tools

*

The second step of the biotechnology process

inserting or introducing new DNA into a cell.

Vectors: plamids or viruses

Transformation

Electroporation

Protoplast fusion

 

14

Intron

*

A region in a eukaryote DNA or mRNA that does not code for a protein and must be removed before translation.

Prokaryotic DNA does not contain introns.

15

Ligase

What is it used for?

*

A class of enzyme that joins two strands of nucleic acids.

It is used in the production of recombinant DNA.

16

mRNA

*

messenger RNA

the type of RNA molecule that carries the codons that direct the incorporation of amino acids into proteins.

17

Mutations

What are the two basic types?

*

Any change in the nitrogenous base sequence of DNA.

Point mutations

Frameshift mutations

18

PCR

*

Polymerase Chain reaction

A technique using DNA polymerase to make multiple copies of a DNA template.

19

Plasmid

What is it used for?

*

A small circular DNA molecule that may be used to insert DNA into a cell.

Used for genetic engineering.

20

Protoplast Fusion

*

A method of joining two cells by first removing their cell walls; used in genetic engineering.

21


Recombinant DNA

*

A DNA molecule produced by combining DNA from two different sources.

22

Repressor Proteins

A protein that binds to the operator site to prevent transcription.

23

Restriction Enzymes

*

An enzyme that cuts double- stranded DNa at specific sites between nucleotides.

24

Reverse Transcriptase

*

An RNA dependent DNA polymerase

An enzyme that synthesizes a cmplementary DNA from an RNA template.

25

What is a Vector?

What are the two types of Vectors?

*

A vector is an agent that is used to introduce the recombinant genes into a cell.

The two types are plasmids and viral DNA.

26

 

 

 

Sticky Ends

*

 

 

single strand DNA pieces which allow the DNA segment to be joined to another piece of DNA that has been cut with the same restriction enzyme.

27

What are siRNA's?

*

Small Interfereing RNA's that shut down pathogen gene activity by binding to the mRNA and preventing translation

 

 

28

What is RNA polymerase?

*

The enzyme thta copies DNA to make mRNA during transcription.

29

Restriction enzymes are
A) Bacterial enzymes that splice DNA.
C) Bacterial enzymes that destroy phage DNA.
B) Animal enzymes that splice RNA. 
D) Viral enzymes that destroy host DNA.

C) BACTERIAL ENZYMES THAT DESTROY PHAGE DNA

30

The value of cDNA in recombinant DNA is that …
A) It lacks exons.   

C) It lacks introns.

B) It's really RNA.   

D) It contains introns and exons.

C) IT LACKS INTRONS

31

The reaction catalyzed by DNA polymerase is
A) DNA → mRNA 

C) mRNA → cDNA  

E) mRNA → protein

B) DNA → DNA 

D) tRNA → mRNA

B) DNA → DNA

32

You have a small gene that you wish replicated by PCR. After 3 replication cycles, how many double-stranded DNA molecules do you have?

8

33

) Which enzyme does NOT make sticky ends?
A) Enzyme Recognition
BamHI G↓GATCC
CCTAG↑G
B) Enzyme Recognition
EcoRI G↓AATTC
CTTAA↑G
C) Enzyme Recognition
HaeIII GG↓CC
CC↑GG
D) Enzyme Recognition
HindIII A↓AGCTT
TTCGA↑A
E) Enzyme Recognition
PstI CTGC↓G
G↑ACGTC


C) Enzyme Recognition
HaeIII GG↓CC
CC↑GG

 

34

Which enzyme would cut this strand of DNA: GCATGGATCCCAATGC?
A) Enzyme Recognition
BamHI G↓GATCC
  CCCTAG↑G
B) Enzyme Recognition
EcoRI G↓AATTC
  CTTAA↑G
C) Enzyme Recognition
HaeIII GG↓CC
  CC↑GG
D) Enzyme Recognition
HindIII A↓AGCTT
  TTCGA↑A
E) Enzyme Recognition
PstI CTGC↓G
  G↑ACGTC


A) Enzyme Recognition
BamHI G↓GATCC
  CCCTAG↑G

35

Gene silencing blocks an undesirable product by
A) Allosteric inhibition of an enzyme. 

D) End-product repression.

B) Making double-stranded RNA.  

E) Blocking transcription.

C) Blocking DNA replication.


B) Making double-stranded RNA.

36

A restriction fragment is
A) A gene.   
C) A segment of DNA.
E) A segment of mRNA.
B) A segment of tRNA. 
D) cDNA.

c) A SEGMENT OF DNA

37

Which of the following processes is NOT involved in making cDNA?
A) Reverse transcription  
C) Transcription 
D) Translation
B) RNA processing to remove introns

D) TRANSLATION

38

The use of an antibiotic-resistance gene on a plasmid used in genetic engineering makes
A) Replica plating possible.
B) The recombinant cell dangerous.    
C) The recombinant cell unable to survive. 

D)Direct selection possible.

E) All of the above.

(AW)
 

D, If antibiotics are added to the media, then only bacteria with the plasmid will grow.  This allows the researcher to directly select the bacteria with the plasmid.

39

You want to determine whether a person has a certain mutant gene. The process involves using a primer and Taq. This process is
A) Translation. 
B) PCR  C) Restriction mapping. D) Site-directed mutagenesis. E) Transformation

(AW)
 

B, Taq polymerase and a primer is used for PCR which can be used to detect a specific nucleotide sequence.

40

Gene silencing blocks an undesirable product by
A) Allosteric inhibition of an enzyme. 
B) Making double-stranded RNA.
C) Blocking DNA replication. D) End-product repression.   E) Blocking transcription.

(AW)
 

B, Also known as siRNA (small interfering RNA), these small pieces of RNA bind to mRNA creating double stranded RNA that tRNA cannot translate. 

41

A source of heat-stable DNA polymerase is
A) Agrobacterium tumefaciens. 
B) Saccharomyces cerevisiae.
C) Pseudomonas. D) Thermus aquaticus.  E) Bacillus thuringiensis
.

(AW)
 

D,  The heat-stable DNA polymerase used for PCR is called Taq polymerase and comes from the thermophilic bacterium Thermus aquaticus.

42

What is Therapeutic in rDNA?

(AW)

1. Production of hormones, insulin, human growth hormone

2.  Production of proteins for subunit vaccines
  


3. Production of small interfering RNAs (siRNA) to shut down pathogen gene activity

4. Production of genes to replace defective genes in gene therapy

43

AM: You have a small gene that you wish replicated by PCR. After 3 replication cycles, how many double-stranded DNA molecules do you have?
A) 2   B) 4   C) 8   D) 16  E) Thousands

 

C) After one cycle you will have 2 molecules, after 2 cycles you will have 4 molecules and after 3 cycles you will have 8 molecules.  The number of molecules doubles with each 

44

RM

Which method uses a vector?

a. Plasmid

b. Protoplast fusion

c. Electroporation

A. PLASMID

45

RM

Agarose Gel Electrophoresis is used for what?

DNA fingerprinting

46

Which of the following is not a therapeutic product and application of recombinant DNA?

a) hormones

b) proteins for subunit vaccines

c) endonucleases

d) siRNA to stop pathogen gene activity

c) endonucleases

47

Name three tools for genetic engineering that do not require a vector.

1) transformation

2) electroporation

3) protoplast fusion

48

49

What tools are used for recombinant DNA?       MP

Restriction Enzymes and Ligases          MP

50

When you are using PCR to make copies of DNA do the orginal DNA strand ever come back together?

 

                                          MG

 

 

No, because they split and are used to make the 2 new DNA copies.

 

Then when you have to 2 new DNA strands they will split and make more copies.

51

What is the process for cDNA?

 

                                              MG

DNA is transcribed into mRNA

Splicesosomes remove the introns and leave the exons.

The exons are then attatched back together.

The new mRNA strand leaves the nucleus and goes into the cytoplasm.

We extract the mRNA out of the cytoplasm and put it in a test tube.

We then add Reverse Transcriptase so the mRNA will reverse transcribe back into DNA.

 

**You know have cDNA**

52

What are the 3 methods of inserting genes without a vector?

 

                                         MG

Transformation

Electroporation

Protoplast Fusion

53

What is Electroporation?

What is a protoplast?

 

                                               MG

The combining of 2 cells

It is also one of the 3 methods used to insert genes without using a vector.

 

A protoplast is a cell that has had its cell wall removed.

54

Of the 2 vectors which one can hold larger DNA pieces.

 

                                                           MG

Viral DNA

55

 

G.L. The substance that protects bacteria from viral DNA:

a) ligase

b) restriction enzymes

c) vectors

d) siRNA

e) cDNA

 

G.L. b) restriction enzymes

56

Which process is considered homologus recombination?

A. Transformation

B. Transduction

C. Conjugulation

D. All of the above

                                 SR

All of the above

57

Can infections cause a mutation?

If so give an example

 

         SR

Yes, Viruses

58

What is transposition?

 

           SR

movement of genes from one place in the DNA to another. An example is jumping genes

59

What does a repressor moecule do?

 

                    SR

blocks RNA polymerase from initiating transcription

60

What does the inducer molecule do?

 

                    SR

Physically pulls the repressor off the operator