Chapter 7 and 8: Microbial Metabolism and Genetics- Part 2

Question 1

Staphylococcus aureus is a common gram ______ bacterium

Answer 1

Positive

Question 2

Drug resistant S. aureus are called

Answer 2

Methicillin-resistant Staphylococcus aureus (MRSA)

Question 3

Antibiotic resistance is a _______ event

Answer 3

Genetic

Question 4

Bacteria have _______ genomes

Answer 4

Haploid (one chromosome)

Question 5

Mutations in bacterial genes alters what?

Answer 5

Genotype

Question 6

What is the genotype?

Answer 6

The DNA-level information encoded by the genome

Question 7

Mutations can also alter…

Answer 7

Phenotype

Question 8

What is the phenotype controlled by?

Answer 8

Proteins by alteration of amino acid composition

Question 9

Organisms that acquire mutations are termed…

Answer 9

Mutants

Question 10

What are the two types of mutations?

Answer 10

Induced

Spontaneous

Question 11

Spontaneous mutations

Answer 11

During normal cellular processes

Question 12

Types of spontaneous mutations

Answer 12

• Nucleotide base substitution (aka point mutation)
• Deletion or insertion of nucleotides
• Transposable elements (“jumping genes”)

Question 13

Induced mutations

Answer 13

Chemicals and radiation can induce mutations of DNA

Question 14

What are mutases?

Answer 14

A type of induced mutation, they are enzymes that are expressed during times of stress that increase rates of mutations

Question 15

What do nonsense mutations do?

Answer 15

Switch something to a stop codon?

Question 16

Mutations are a ______ biological process

Answer 16

Natural

Question 17

All DNA polymerases have..

Answer 17

Inherent mutation rates

Question 18

IN times of stress, mutational rates..

Answer 18

Increase

Question 19

What would happen without mutations?

Answer 19

Evolution cannot occur and organisms will be ill-equipped to adjust to changes in their environment

Question 20

Evolution requires what three events?

Answer 20

• Genetic variation, which is mostly random
• The variations must be heritable
• Natural selection of those traits most suitable for an environment

Question 21

What are competent cells?

Answer 21

Cells that are receptive to DNA transfer

Question 22

The process of becoming competent is largely unknown, but requires _______ ________

Answer 22

Protein synthesis

Question 23

What do competent cells permit?

Answer 23

DNA to pass through their cell walls and membranes

Question 24

What is transformation?

Answer 24

The process of competent cells allowing DNA to pass through their cell walls and membranes, can lead to the acquisition of new genes

Question 25

Can competent cells be induced artificially?

Answer 25

Yes, they play an important role in biotechnology

Question 26

DNA-mediated transformation has to do with...

Answer 26

Competence

Question 27

Transduction

Answer 27

Bacteriophages frequently incorporate genes from previously-infected host cells

Question 28

What happens when progeny viruses infect other bacteria?

Answer 28

The new genetic information can be recombined with the host's genome

Question 29

What are plasmids?

Answer 29

Circular pieces of DNA

Question 30

How long are plasmids?

Answer 30

They can be hundreds to thousands of nucleotides long

Question 31

Plasmids frequently contain _______ ______ that contribute to disease susceptibility

Answer 31

Virulence factors

Question 32

Virulence factors (common)

Answer 32

Antibiotic resistance | Toxins

Question 33

Why are plasmids considered promiscuous?

Answer 33

They can disseminate between species of bacteria

Question 34

What are plasmids commonly used in biotechnology for?

Answer 34

Gene cloning and recombinant protein production

Question 35

What is conjugation?

Answer 35

The direct transfer of plasmids (or chromosomes) between bacteria

Question 36

Competent cells acquire plasmids by...

Answer 36

Random chance

Question 37

Conjugation 4 Step Process: First Step

Answer 37

Contact between a donor cell (F+) and recipient cell (F-) is mediated by a sex pilus, a tubular structures

Question 38

Conjugation 4 Step process: Step 2

Answer 38

The plasmid becomes mobilized by an enzyme that cleaves the plasmid

Question 39

Conjugation 4 Step Process: Step 3

Answer 39

One strand of the double stranded plasmid is transferred to the recipient, presumably through the pilus

Question 40

Conjugation 4 step process: Step 4

Answer 40

The copies of the plasmids are used as templates for DNA synthesis

Question 41

Each strand of the plasmid has..

Answer 41

Enzymes to make another strand

Question 42

Can penicillinase be passed through conjugation?

Answer 42

Yes and it makes organisms resistant to penicillin

Question 43

Transposons

Answer 43

Transposable elements, jumping genes, are self-replicating DNA molecules

Question 44

The mobile gene pool- transposons occur in...

Answer 44

Virtually all organisms

Question 45

When transposons jump, they...

Answer 45

Frequently take adjacent genes with them, such that integration in another cell leads to the introduction of novel genetic information (Slide #26)