Exam 2

Question 1

ampicillin

Answer 1

a member of the “cillin” family of antibiotics
able to withstand highly acidic conditions (oral prescriptions)
treats things like respiratory infections, UTI’s, meningitis, salmonella infections
can be injected, taken orally, or intravenously

Question 2

bacteriostatic agent

Answer 2

one of the levels of growth control for bacteria
less deadly than the other two
does not actually kill bacteria, just prevents or slows reproduction
can keep bacteria levels at a “safe” level
example: refrigeration

Question 3

broad-spectrum antibiotic

Answer 3

an antibiotic that works against both Gram-negative and Gram-positive bacteria
example: tetracyclines
they block the synthesis of new proteins

Question 4

competitor

Answer 4

this is how sulfa drugs work
it competes for an enzyme in most bacteria that performs one step in the production of bases: converting PABA into folic acid
the sulfa drug attaches to the active site instead of the substrate (PABA) and prevents the production of folic acid
does not kill human cells because our cells do not need folic acid, but absorb it from the blood

Question 5

covalent bonds

Answer 5

the strong bonds that hold atoms together as building blocks and building blocks together as molecules
it is the sharing of electron pairs b/t atoms
a stable balance of attractive and repulsive forces b/t atoms

Question 6

filtration

Answer 6

another method of bacterial growth control
does not kill the bacteria, only removes from the liquid that is being filtered
most advantageous when liquid cannot be heated (ex. pools)
forces liquid thru some kind of filter that the bacteria are too large to fit thru the holes

Question 7

folic acid

Answer 7

it is a B vitamin
bacteria have to make it b/c it cannot be absorbed thru the cell wall
human cells can absorb it from the blood thru the PM
necessary for growth and to perform important functions inside the bacterial cell
used for making DNA, normal red blood cells, and for fetal development of the nervous system in human cells

Question 8

germicidal agent

Answer 8

a level of bacterial growth control
kills MOST bacteria and viruses (meaning most of ALL kinds)
can reduce the bacteria down to a “safe” level
examples: sanitizers and antiseptics

Question 9

halogens

Answer 9

a part of the chemical methods for killing bacteria
examples: iodine, chlorine, bleach
they “steal” the bonds b/t bases and cause broken chains, and therefore broken proteins - lethal

Question 10

non-covalent bonds

Answer 10

weak bonds that hold molecules together as cell parts (ex. ribosomes)
ionic bonds
more easily broken by water, especially heated water

Question 11

pasteurization

Answer 11

only a germicidal method of sterilizing
the liquid is held at a temp of 145 degrees for 30 minutes
reduces the number of bacteria to a “self level” b/c things like milk cannot be held at a higher temp less it curdles

Question 12

penicillinase

Answer 12

an enzyme created in bacteria by a gene that allows the bacteria to be resistant to penicillin
it works by breaking one bond b/t the atoms in the penicillin molecule
this changes the shape of the penicillin and makes it ineffective
resistant bacteria have been sharing this gene with other bacteria, so resistance is spreading

Question 13

phenolics

Answer 13

one of the chemical methods of controlling bacterial growth
examples: Lysol has phenolic compounds
works by making the individual proteins in the cells cytoplasm glom together
then they cannot move around the cell to do their jobs and the cell dies

Question 14

polymyxins

Answer 14

a type of antibiotic
works by puncturing bacterial PM
the contents of the cytoplasm then leaks out and the cell dies
able to discriminate b/c bacterial PM do not contain cholesterol, human cells do

Question 15

radiant energy

Answer 15

a method of controlling bacterial growth
total radiant energy exposure is applied (TREE)
works primarily by breaking the strong covalent bonds b/t bases of DNA
different types used: UV (needs long exposure) and can kill all bacteria except endospores
x-rays and gamma rays stronger - can go thru any surface
mostly used for things that cannot be heated (solids and plastic medical supplies)

Question 16

rifampin

Answer 16

a type of antibiotic
works by blocking the formation of mRNA from DNA templates
side effects to human cells minimal b/c bacterial RNA polymerase is different from eukaryotic RNA polymerase

Question 17

sterilizing agent

Answer 17

the ultimate form of bacterial growth control
kills ALL bacteria, even endospores, and viruses
most effective, but also the most difficult to obtain

Question 18

streptomycins

Answer 18

a type of antibiotic
take advantage of the fact that human and bacterial call’s ribosomes are made of different proteins
stick to the bacterial ribosomes and make them unable to function
work best with Gram-negative bacteria
treats infections like tuberculosis

Question 19

sulfa drugs

Answer 19

first antibiotics discovered around 1939
contain an atom of sulfur
works by impersonating the natural substrates and then the enzyme attaches to the impostor that matches its active site
the enzyme then cannot perform its important job and the cell cannot function properly
specifically aids in the inhibiting of making folic acid

Question 20

TCE

Answer 20

“total chemical exposure”
means the correct combination of the chemical’s concentration and the length of exposure to it
high concentrations would be too dangerous b/c it would also kill human cells - therefore it is mostly a germicidal method of controlling bacterial growth
example: mouthwash

Question 21

tetracycline

Answer 21

a type of antibiotic
considered a broad-spectrum antibiotic
kills both Gram-negative and Gram-positive bacteria
works by blocking the synthesis of new proteins
used to treat UTI’s, acne and skin infections, and even cholera

Question 22

THEE

Answer 22

“total heat energy exposure”
composite of temperature and time
either providing a higher heat for a shorter time, or a lower heat for a longer time

Question 23

TREE

Answer 23

“total radiant energy exposure”
the correct combination of energy and time
can be used to kill cells if enough TREE is used
severely damages the templates that the cell needs to make new proteins

Question 24

antibodies

Answer 24

proteins made by immune systems cells
attack viruses by sticking to their spike proteins
prevents attachment, therefore the virus gets washed away of phagocytosed
neutralizes the virus

Question 25

AZT

Answer 25

an antiviral drug - a base analog
delays the development of AIDS
modified “T” cannot be added onto, so copying stops
no new viral DNA copies are available to package inside capsids to make new virus particles

Question 26

base analog

Answer 26

modified bases which look like bases but don’t work like bases
“impostors”
occasionally one of these impostors is added to the growing chain of bases instead of the normal base b/c it tricks the DNA polymerase
stops the copying of viral DNA

Question 27

envelope

Answer 27

a membrane on the outside of the capsid in a virus
a true membrane made of lipids and proteins
proteins called spike proteins
not all viruses have an envelope

Question 28

helical capsid

Answer 28

one of the forms that the proteins of the capsid takes
the proteins are linked into a long chain
coiled
DNA is inside of this capsid

Question 29

Herpes

Answer 29

a virus capable of forming latent infections
causes cold sores, or fever blisters, and genital infections
come and go, the virus alternates b/t lytic and latent stages
“herpes simplex” or HSV

Question 30

host cell

Answer 30

the cell that a virus is infecting
is basically hijacked by the virus and all of its nutrients are used to create new viruses
uses things like ribosomes, ATP, enzymes, building blocks
host cell virtually becomes a “virus factory”

Question 31

latent infection

Answer 31

happens when the virus splices itself into the host cell’s chromosome
the host cell doesn’t even know that the virus is there
no symptoms of illness
viral DNA is copied right along with the host cell’s DNA
very slowly spreading from one infected cell to its daughter cells in 24 hours

Question 32

lytic infection

Answer 32

when a virus infection ends with the host cell dying by lysis
can happen due to two things: the cell hasn’t kept up w/ maintenance b/c its parts have been focusing on virus replication OR b/c there’s just too many viruses inside so it explodes
either the cell explodes or the virus escapes via budding and then eventually the host cell dies

Question 33

neutralization

Answer 33

when the antibodies attach to the spike proteins on the virus
renders it unable to attach to any receptors
renders the virus unable to replicate

Question 34

neutrophils

Answer 34

work by phagocytosing viruses
wraps around virus and pulls it into cytoplasm, wrapped in a compartment called phagosome
lysosome fuses w/ phagosome and disassembles virus
basically a white blood cell

Question 35

phagosome

Answer 35

the compartment/vesicle the neutrophils envelope viruses in in order to fuse w/ lysosome and disassemble the virus
a vacuole in the cytoplasm of the cell
formed by the fusion of the cell membrane around the particle

Question 36

polyhedral capsid

Answer 36

one of the forms that the proteins of the capsid takes
when proteins are linked together into small patches to form a polyhedral around a virus
“many sided”
DNA is inside of the capsid

Question 37

spike proteins

Answer 37

proteins that stick out like spikes from the envelope or capsids on viruses
enable the virus to attach to cells in order to infect them
some are clearly visible, some are not (like those on enveloped viruses)