Chapter 5&7

Question 1

Inhibits bacterial growth

Answer 1

Bacteriostatic

Question 2

Chemical capable of killing bacteria

Answer 2

Bactericidal

Question 3

Agent used to inhibit or kill growth, used on skin or mucous membrane

Answer 3

Antiseptic

Question 4

An agent used to inhibit growth/kill bacteria on inanimate objects

Answer 4

Disinfectant

Question 5

_______are stages in the life cycle of certain intestinal protozoan pathogens like Giardia lamblia. They are disinfectant-resistant forms that appear in the feces of infected animals, including humans. They are easily destroyed by boiling.

Answer 5

Cycsts

Question 6

Enzyme that binds to DNA during replication and matches complementary base pairs. 5-3 direction

Answer 6

DNA polymerase

Question 7

Makes primers with the use of RNA, needed to start DNA strand replication

Answer 7

primase

Question 8

A series of three nucleotides that code for a specific amino acid

Answer 8

codon

Question 9

Transcription vs translation

Answer 9

Transcription: info from DNA is encoded into RNA
Translation: mRNA is used to synthesize encoded protein (amino acid)

Question 10

Nucleotide sequence RNA polymerase binds to start transcription

Answer 10

Promoter

Question 11

Semiconservative

Answer 11

During binary fission, the replication of bacterial DNA, two molecules created contains one of the original stands paired with a newly synthesized strand

Question 12

These enzymes temporarily break and unwind the DNA helix at the origin of replication (to initiate DNA replication, there is only ONE origin of replication in bacterial cells)

Answer 12

helicase and gyrase

Question 13

anticodon

Answer 13

three complementary nucleotides in tRNA molecule that recognize and bind to associated mRNA

Question 14

Inducible enzymes

Answer 14

Synthesis can be turned on as needed. The genes for the enzyme that hydrolyzes lactose are turned on when lactose is present.

Question 14

Allows bacteria to “talk” to each other via molecule synthesis.
Low cell density=low signal molecule.
High cell density=high signal molecule.
At a certain density, the expression of genes changes.

Answer 14

quorum sensing

Question 15

Repressible enzymes

Answer 15

enzymes that are produced routinely but their synthesis can be turned off when not required.

Question 15

operon

Answer 15

PROG(t). closely related genes that act as a single unit

Question 15

constituents of operon

Answer 15

promoter, repressor, operator, genes, terminator

Question 16

DNA is synthesized in the ________ direction

Answer 16

5’ to 3’

Question 17

Enzyme: joins DNA fragments on the lagging strand

Answer 17

DNA ligase

Question 18

Enzyme: relieves tension from unwinding DNA strands; breaks hydrogen bonds

Answer 18

DNA gyrase

Question 19

Enzyme: builds primers (3 nucleotide grouping of DNA to start replication at the fork or between lagging strands)

Answer 19

primase

Question 20

start codon

Answer 20

AUG

Question 21

STOP codons

Answer 21

UAG, UGA, UAA

Question 22

What technique to use for controlling microbial growth on: drinking water

Answer 22

filtration

Question 23

What technique to use for controlling microbial growth on: surface lab benches

Answer 23

U.V. (non-ionizing) radiation - less energy/longer waves

Question 24

What technique to use for controlling microbial growth on: food such as fruits and meats to kill ENDOSPORES

Answer 24

Gamma (Ionizing) radiation - short wave, higher energy

Question 25

What technique to use for controlling microbial growth on: sterilizing heat-sensitive solutions such as beer

Answer 25

Filtration

Question 26

Chemical control: destroys cytoplasm membrane and denatures proteins, not good for skin. Very effective, found in Lysol

Answer 26

phenol/phenolics (used as antiseptic/disinfectant)

Question 27

Chemical control: Damage proteins, not to be used as an antiseptic, could be used in small portions to clean water

Answer 27

Halogens (Chloride, Iodine)

Question 28

Chemical control: Denatures proteins and lipid bilayer, common antiseptic in diluted portions. non-toxic, evaporate quickly

Answer 28

Alcohol

Question 29

Chemical control: Interferes with protein/enzyme function by binding to sulfhydryl- groups. in bandaids, used to treat scratches. Not very many used due to environmental concerns.

Answer 29

Metal (silver nitrate)

Question 30

Chemical control: Hydrophobic and hydrophilic regions, reduce the surface tension of liquids and wash away microbes

Answer 30

Quats (soaps)

Question 31

Chemical control: Low toxicity, used in many antimicrobial products; disrupts cell-membrane

Answer 31

biguanides