Exam 2 Flashcards
0
Q
What are some. Simple ways we can control microbial. Growth?
A
Hand washing, showers, brush teeth, wash clothes, refrigeration
1
Q
Who were the major contributors to inventing ways to control microbial growth?
A
Semmelweis and Pasteur
2
Q
What. Are hey he. 2 major types of microbial growth. Control?
A
Sterilization
Disinfection
3
Q
What is seterilization?
How many microbes eliminated?
A
Destruction of ALL microbes
All human pathogens are eliminated
4
Q
What is disinfection?.
Are all microbes eliminated
A
Use of a chemical or physical agent. To inhibit or destroy microbes on surfaces or inanimate. Objects.
Not all human pathogens. Are eliminated
5
Q
What are the types of disinfection?
A
Antisepsis
Sanitization
Pasteurization
6
Q
What. Is antisepsis?
A
Disinfection of. Tissue via. A. Chemical agent
Must be. Safe. To. Use on tissue
7
Q
What Is sanitization?
A
Reduce number. Of pathogens On a surface to meet public health standards
8
Q
What is pasteurization?
A
Use. Md heat to kill pathogens and decrease number of spoilage. Organisms,
Increases shelf life of. Food/beverages
9
Q
What are the 8 things to consider when thinking to microbial growth control?
A
- Number of microbes- more microbes takes longer. Time to. Kill
- Duration of exposure-how long does it. Take?
- Types. Of microbes- endospore former, acid fast bacteria?
- Temperature- decreased temp molecular. Motion of molecules decreased
- Concentration of the chemical
- Ph- alkaline ph is. Harder. For microbes
- Environment- presence. Of. Organics (blood, pus, ect)- decreased accessibility, organically interfere with action of some chemicals
- Endospore formation
10
Q
What are the targets/how do antimicrobial agents inhibit/kill microbes? Three ways
A
Alteration of membrane permeability
Denature proteins
Damage nucleic acids
11
Q
How does an anti microbial agent alter membrane permeability?
A
Microbe burst/shrivel
Leak necessary items out of microbe
Not allow. Necessary items. Into microbe
12
Q
How do antimicribial agents denature proteins?
A
Unfolding proteins doesn’t maintain. 3D shape, won’t function
Denature enzymes
13
Q
Hw do antimicrobial agents damage nucleic Acids?
What molecules does it target?
A
Block DNA replication, transcription, translation
DNA and RNA
14
Q
What are the 6 different kinds of physical microbial growth. Control?
A
Heat Cold Drying Filtration Osmotic pressure Radiation
15
Q
For heat, what is the action, cost, target,time frame and types?
A
Denatures proteins Inexpensive Kills lots of microbes Fast Dry heat, incineration, moist heat, autoclave, pasteurization
16
Q
How does time and temperature matter. With mycobacterium tuberculosis?
A
Higher the temperature,the shorter time of exposure:
58- 30 minutes
65-2 minutes
72-3 seconds
17
Q
What is a example of dry heat? Temp and time? Does it penetrate? What can you disinfect, what can you not? Can it be a sterilizer?
A
Oven 160 C~2 hours No Glassware/instruments, not liquids Yes
18
Q
What is a example of an incinerator?
Sterilizer?
What can you use it on?
A
Bacti-cinerator
Sterilizer
Must be metal and able to take extreme heat
19
Q
Does moist heat penetrate?
What is a example?
Sterilization?
What microbe can survive boiling?
A
Yes
Boiling
Not reliable sterilization
Endospores
20
Q
What takes longer or sterilize? Moist or dry heat?
A
Dry heat takes more time
21
Q
What two physical things does autoclave combine?
What must be maintained for it to sterilize?
What can you use it on? Can’t?
When must you test it.
What is used so you can tell it was effective?
A
Moist heat and osmotic pressure Temp and pressure Glassware, liquids, instruments, microbial media NOT on plastics, will melt Frequently Autoclave tape
22
Q
Does pasteurization sterilize? How doss it work? What is the holding method? Flash method? ultra flash method?
A
No, it disinfects Kills pathogens and spoilage. Organisms with heat 62.9 for 30 minutes 71.6 for 15 seconds 140 for 3 seconds
23
Q
What is cold action?
Who does it work on?
A
Decrease growth, metabolism, reproduction
Fridge halts growth. No most human pahogens (mesophiles)
24
What is the action of drying?
Examples
Method example
Decrease metabolism (requires water)
Dry fruit, grains, peas, beans. Yeast
Lyophilization-removing water under vacuum
25
Action of filtration?
Examples
Examples of what it is used on
Pores in the filter trap microbes
Surgical masks, HEPA filters
Pharmaceuticals, vaccines, blood products
26
Action of osmoti. Pressure
| Examples
Shrivel/burst microbe
| Jam, jelly, honey
27
Action of radiation?
| Two types
Damages DNA
Ionizing radiation
Nonionizing radiation
28
What rays does ionizing radiation use
| What is it used on/for?
Gamma and X-rays
Preserve food
Drugs,vaccines, medical instruments
29
What rays do non ionizing radiation use?
| Where is it used?
Uv light
| Operating rooms, labs, morgues
30
What are. The 9 different types of chemical methods for microbial control?
```
Phenol and phenolics
Soaps/detergents
Alcohol
Heavy metals
Chlorine
Iodine/iodophors
Aldehydes
Gaseous sterilizers
Peroxides
```
31
How does the presence. Of organic effect the effectiveness of chemical agents?
Decreases. The. Effectiveness
32
What does a chemical for microbial control. Label. Usually include?
Microbes it is effective against,
Duration of exposure
Chemical agent used
33
What are phenols/phenolics effective against.
| Action?
Gram positive bacteria and some fungi
| Alter membrane permeability,denatures proteins
34
Who was the first to use phenol?
What are its drawbacks?
What did they do to lessen this. Problem?
Lister during surgery
It. Is toxic/caustic, and very expensive
Chemically altered no phenol. To. Produce phenolics, which is less irratibile qualities
35
What are phenolics used for?
```
Hard surface disinfectant
Skin cleanser (phenolic+detergent)
Throat lozenges/sprays ( antiseptic)
Triclosan (tons of products)
Hibiclens
Clove and pine oil are phenolics,antiseptics/disinfectants
```
36
What is soap?
What is its ph?
Commonality?
Fat and lye
9-10
Very hard to find
37
What is detergent made of?
| Why is it better than soap?
Made from petroleum products
| More soluble in water
38
Why is a surfactant
What are some examples?
How does it work?
Surface-active agent
Soap and detergent
Decreases surface tension so things are rinsed away in water
39
What are soap/detergents effective against?
What is their action?
How does it do this?
What is sometimes added
Broad-range of microbes
Mechanical removal of microbes
- surfactant decreases surface tension on skin. Breaking apart oil on skin, lifts off microbes so they can be rinsed away in water.
-surfactant has a polar end and no polar end. No polar end grabs
microbe, polar end mixes with water and washed away.
Chemicals are sometimes added
40
How does hand washing affect infection rates in hospitals?
Decreases it by 50%
41
What a a alcohol affective against?
| Action?
Vegetative bacteria, enveloped viruses, fungi,some Protozoa
| Damages their membranes, dissolves some lipids, and denatures proteins
42
For alcohol to be effective what is the dilution percent? What else is needed?
What is it used as or in?
What is thproblem with it?
What is added to increase effectiveness?
```
70%
Water
Skin antiseptic, and hand sanitizer
Evaporates quickly so duration of exposure sins hard to reach
Detergent chemical
```
43
What are heavy metals effective against?
Action?
Three examples
Broad range of microbes
Denature proteins
Silver, mercury,and zinc
44
What are some things silver is used in?
Silver nitrate drops In the eyes of newborns, burn cream, wound ointment,silver impregnated catheters
45
What is mercury used in.
Mercurochrome(antiseptic)
| Preservative
46
What is zinc used in?
Dandruff shampoo, some mouthwash
47
```
Chlorine is effective against?
Action?
Example?
Most affective amount?
What is it used on?
```
Broad range of microbes
Denatures proteins
Sodium hypochlorite (main ingredient in bleach)
10% solution
Dialysis equipment, food processing, pools
48
Iodine is effective against?
Action?
What is a example?
What is an iodophors? What are they used for?
Broad range of microbes
Denature proteins
Betadine- aqueous iodine for skin antiseptic
Iodine and detergent for disinfecting surfaces
49
Aldehydes are effective against?
Action?
3 examples?
What are aldehydes used for?
All microbes! A sterilant
Denature proteins
Formaldehyde, formaline, gluteraldehyde
Slide fixing, preserving biological specimens, embalming, dialysis equipment, respiratory therapy equipment, endoscopes, instruments
50
Compare formaldehyde, Formalin, and Gluteraldehyde.
Colorless gas with a pungent odor
37% solution of formaldehyde and water! expensive, smells real bad
Tweaked version of formalin/formaldehyde, less expensive, safer, smells better, and more effective
51
Gaseous sterilizers are eeffective against?
Action?
Example? Characteristics? What is it used for?
All microbes (sterilant)
Denatures proteins
Ethylene oxide
-must be in a closed chamber, explosive, toxic to humans, takes 1-3 hours in chamber to sterilize
-plastics, sutures, heart valves, heart-lung machines,mattress, buildings
52
What are peroxides?
Effective against?
Action?
What are three examples?
Oxidizing agents, they steal electrons from proetiens
Anaerobes
Oxidizing a gent, denatures proteins
Hydrogen peroxide, ozone, peracetic acid
53
What is hydrogen peroxide used for?
What do bubbles mean?
Want is the equation?
What is the best type of wound and why?
Skin antiseptic
There is oxygen present, means aerobic respiration is happening and hydrogen peroxide is not working
H2O2---catalase----->2H+ + O2
Anaerobic wounds, because anaerobes don't produce catalase so hydrogen peroxide can then denature proteins
54
What is ozone used for.
| Paracetic acid?
Disinfect air, water/industrial settings, cooling towers
| Space shuttle, probe, rover...
55
What are four ways that infectious disease was treated historically?
100 years ago, how many kids died before what age?
Enemas, blood curdling ice baths, deadly starvation, blood letting
1/3 of kids died before age 5
56
Who invented the magic bullet and what Does it do?
What did he make hundreds of compound out of?
What was his 606 compound?
Effective against what?
Why was it stopped?
```
Paul ehrlich
Kills pathogens but not humans
Arsenic-phenol
Salverson
Syphilis
Stopped due to toxicity
```
57
Who was over the company that produced a dye called??
When tested in animals, what kind of bacteria did it inhibit?
Who was the first human he tested it on? Why?
Did it work?
Did he get a Nobel prize?
```
Gerhard domagk
Prontosil
Gram positive bacteria
His daughter because she poked herself with a needle, got an infection in her arm, md was going to amputate, he injects her with prontosil
It works!
Yes Nobel prize!
```
58
Who discovered antibiotics?
What microbe was he originally studying?
What contaminated his streak plate? How did that contaminate affect the microbe he was studying?
What did he name the substance that inhibited growth?
Could he isolate this substance?
Alexander Fleming
Staphylococcus
Penicillium
Where penicillium grew, staphylococcus did not grow.
Penicillin
Can not isolate substance, so publishes a paper
59
Who figured out how to isolate penicillin?
| Who won the Nobel prize?
Howard Florey and Ernst chain
| Both of them and flemming
60
Who was the dirt microbiologist?
What did he isolate?
What was the term that he invented?
Nobel prize?
Selman Waksman
Streptomycin
Antibiotic
Nobel prize yes
61
What is an antibiotic?
Product of or derived from a microbe that can inhibit or kill other microbes. NATURAL
62
What is an antimicrobial drug?
Synthesized in the lab that can. Inhibit. Or kill microbes
| ARTIFICIAL
63
What bacteria produces half. Of all antibiotics?
Streptomyces
64
Why do microbes produce antibiotics?
WE HAVE NO IDEA!!!!!
65
What a re the 7 qualities of an ideal antibiotic/antimicrobial drug?
1. Inhibit/kill pathogen with out harming the host
2. Cause no allergic reaction in there host
3. Stable as a solid or a liquid
4. Remain in specific tissue long enough to be effective
5. Inexpensive
6. Not harm normal flora
7. Inhibit/kill pathogen before the pathogen becomes resistant
66
What are the 5 different targets of anibiotics/antimicrobial drugs?
Why do they not work on viruses?
1. Bacterial cell wall
2. Disrupt membranes
3. Nucleic acid synthesis
4. Block protein synthesis
5. Metabolic pathways
Viruses don't have any these targets
67
How does it target the. Bacterial cell wall?
What. Antibiotics work?
What bacteria. Is it effective against?
Why does it not work on the other kind and why?
Blocks synthesis of. Peptidoglycan and microbe dies due to osmotic pressure
Penicillin, vancomycin, bacitracin, ampicillin
Gram positive bacteria
Gram negative has outer. Membrane blocks access to. Peptidoglycan.
68
What does disrupting the. Membrane do?
What kind of membranes does. It work on?
What type of bacteria is it effective against?
Why not the other kind and why?
What is a downside, and how do. Use it to overcome that?
Inhibits function of membrane
Outer membrane of gram neg bacteria, or a cell membrane (cell basic)
Gram positive. Bacteria, because cell membrane is blocked by thick cell wall
Can. Be toxic to humans, and our cells have cell membranes, so we try to use it only as a topical
69
How does nucleic acid synthesis target work?
Effective against?
Downside?
What are ozone exceptions that. Only target bacteria?.
Blocks synthesis. Of DNA and RNA, stops DNA replication, transcription, and translation
Bothe. Gram pos and gram. Neg. bacteria
Most are toxic to humans
Rifamycin targets bacterial RNA. Polymerase
Quinolones target bacterial DNA gyrase
70
How come blocking protein synthesis can be specific to bacteria?
Examples of antibiotics
Effective against?
Ribosomes of prokaryotes are smaller than ribosomes of eukaryotes
Erythromycin, streptomycin, tetracycline
Gram. Pos and gram neg
71
How do they inhibit via metabolic pathways? Two ways
How does the second way work?
Example?
Effective against.
1. Work as a competitive inhibitor, block active site of an enzyme, they use enzymes that play a role in metabolism
2. Block colic acid synthesis
-flock acid is needed to produce DNA, prokaryotes produce their own folic acid whereas eukaryotes do not
Sulfa drugs
Gram positive and negative
72
What are narrow-spectrum effective against?
What is an example?
When do you use it?
A limited type of microbe
Penicillin and other antibiotics that target peptidoglh an synthesis, only effective against gram pos bacteria
Used when pathogen is known.
73
What are broad spectrum effective against?
And example?
What type of bacteria is it effective against?
When is it used?
Downside?
How do you counteract?
```
Against multiple microbes
Tetracycline, target protein synthesis
Both gram positive and negative
Pathogen is unknown
Damages all normal flora, risk of super infection or secondary infections
Probiotics
```
74
What test is used to determine which antibiotic to use?
Kirby-Bauer sensitivity testing
75
What are the routes of administration of Antibiotics/antimicrobial drugs?
How do they come or are they given? Concentration related to dose time? Downsides? Benefits?
Topical-cream, local treatment
Oral- self-administer, lower conc. so longer dose time
IM/IV- high concentration so shorter dose time
76
Are there many microbes naturally resistant?
| How do they gain resistance?
Not many materially resistant
| Via mutation, conjugation, translation, transformation
77
What does resistance mean?
To. Have a gene to. Produce an enzyme ant ay breaks apart antibiotics/antimicrobial drug
OR there is a change in the target of the antibiotic/antimicrobial drug.
78
How is MRSA resistant?
What percentage was resistant in 1980? And then in 200?
How is MRSA acquired?
It acquired a gene (BLA) that produces an any me that. Breaks apart penicillin. And derivatives. Of it
Via hospital
79
What are superbugs?
Bacteria with multiple anitbiotic/anti microbial drug resistance
80
What is the biggest issue with resistance?
Inappropriate antibiotic/antimicrobial useage
They are used for viral infections such as ear infections (30% of scrips are inappropriate), or colds, flu (100% of scrips aren inappropriate)
Large doses for. Pre and post op
81
How can we prevent. Resistance?
Perform gram stains, rapid strep tests
Educate. Public, md, health. Care workers
Patient education on. Taking entire course
Hand hygiene
82
Why are some genes transcribed/translated all the time and some not?
If the product is needed all the time, it will be transcribed and translated all the time.
If the product is not needed, it won't be transcribed nan translated constantly.
83
What is an operon?
| What part of it is responsible for controlling transcription and translation?
Section of DNA that contains one or more structural genes along with a regulatory gene.
The regulatory gene controls the transcirptiona md translation of the structural genes.
84
Wht do they're structural Genes on the lac operon produce And what do they do?
What is the lac operon an example of?what is this?
How does the regulation work?
Enzymes needed to break apart lactose
Inducible operon=usually not transcribing of translating structural genes. "Off" but can be turned "on".
- if no lactose is present in the environment, regulatory gene produces a repression protein that blocks transcription/translation of the structural genes.
-if lactose is present in the environment, lactose binds to repressor protein and blocks repressor protein from blocking transcribed/transl of the structural genes. Enzymes now being produced to break down lactose
85
What is an inducible operon?
Usually "off" but can be turned back "on"
86
What does the try's operon produce?
What is it an example of? What is this?
How is it regulated?
Amino acid tryptophan
Repressible operon= usually transcribed/translating the structural genes "on" producing tryptophan, but can be turned "off"
-when no tryptophan is present in the he environment, we must produce tryptophan, regulatory gene is producing a repressor protein but the Repressor Protein is inactive and not blocking transcription of the structural Genes, "on" producing tryptophan.
-when tryptophan is present in the environment, use this free Tryptophan so turn the structural genes "off". Repressor protein becomes active and blocks transcription/translation of the structural genes use free tryptophan in the Environment and not produce tryptophan "off"
87
```
What is a mutation?
How often does it happen?
How can they happen?
What are the three effects?
Most common type?
What enzyme catches mutations?
```
Permanent change I an organisms DNA
1 mutation per 1 billion DNA replications bacteria
Spontaneously or mutagen induced
Neutral, beneficial, or harmful
Point mutation-mutation effects just one base pair of DNA
DNA polymerase
88
What are two reasons for spontaneous mutation?
What is a mutagen?
What are 5 examples of mutagens?
Natural exposure to uv light, errors in DNA replication
A Chemical or physical agent that causes mutation
X-rays, gamma rays, experimental exposure to uv light, benzopurene(smoke)
89
What is A point mutation?
Mutation that affects just one base pair of DNA
90
What is the Ames test used to determine?
What is it use on and for?
How did Ames do it?
Why did he. Make the. Mutant strain?
Used to determine if a chemical is a mutagen of salmonella, if it is, it may be am usage in humans, and if a mutagen in humans, it may be a Carcinogen.
Use bacteria to scree chemicals
-Ames made a mutant strain of salmonella, this mutant salmonella can't produce the amino acid histidine. Must provide histidine in the media or this mutant salmonella can't grow.
-combined chemical+liver extract(histidine source)+mutant salmonella
-growth= chemical reversed the mutation= mutagen of salmonella
-no growth= chemical Is not Mutagen of salmonella
91
What is a carcinogen?
Cancer agent in humans
92
What Is genetic recombination?
Where a donor microbe donates DNA to a recipient microbe, recipient microbe is going to add the Donor to its existing DNA. Recipient microbe now has DNA it did not have before that joined for como bed with its existing DNA
93
What are the three mechanisms of genetic recombination?
Transformation
Transduction
Conjugation
94
What is the jist of transformation?
Longer version?
Examples of genes transferred this way?
Transfer and integration of donor DNA fragments from dead, lysed bacteria into recipient bacteria.
When bacteria die, they lyse (burst) and their DNA (main Chromosome and Plasmid DNA if they have it) is released into the environment, some bacteria in the environment pick up those DNA fragments and add that donor DNA to their DNA.
Include genes. For. Capsule production and. Enzyme production(BLA)
95
Who was these scientist that figured out transformation of Genes?
What microbe he use? Why were the two strains important?
What was the experiment?
What did he conclude?
Griffith
Streptococcus pnuemoniae that. Causes pneumonia.
There was an s strain (smooth colonies, produces capsule, causes pneumonia) and an. R strain (rough colonies, no capsule, no pneumonia).
*something transformed r strain bacteria Into living s strain bacteria.
Griffith take the s strain heats it (destroys capsule) and injects it into mice, mouse. Lives,no pneumonia.
- then he injects heated s strain + r strain and mouse dies of pneucmonia. He. Finds live healthy s strain in mouse.
96
Who set out to finish griff ethos experiment and find the transforming factor.
What is the. Transforming factor?
How was the r strain transformed?
Avery, my cloud, McCarty
DNA
Heated s strain lysed and released DNA in to the environment, among. The DNA is the gene to produce a capsule, s strain took up DNA to produces. Capsule and added it to their DNA
97
In transformation, what is a donor bacteria?
Recipient bacteria?
In griff ethos experiment, which bacteria was which?
One that releases DNA into the environment via lysing
One that takes up DNA from their environment
S strain was donor
R strain was recipient
98
What is the limitation of transformation?
How many are naturally this way?
How can we overcome this?
Only competent bacteria can take up DNA from their environment
less than 1% are naturally competent
We can make bacteria competent via calcium chloride and Extreme temperature changes.
99
What is the jist of transduction?
Transfer of DNA from donor bacterium to recipient bacterium via bacteriophage
100
What is a bacteriophage?
What are examples of genes that can be transferred via transduction?
What is a drawback of transduction?
Virus that only infects bacteria
Exotoxins, drug resistance, enzymes for catabolizing sugars
When viruses infect a host cell, it is very SPECIFIC, must be able. To infect both donar and recipient bacteria.
101
What are the 8 steps In transduction?
1. Bacteriophage binds to donor bacterium
2. Phage injects its DNA into donor bacterium
3. Phage breaks. Apart. The donor bscteriums DNA
4. Phage DNA uses the donor bacterium cell a chi dry to pro Duce phage components
5. Assemble. Progeny phage,most phages end up with phage DNA, but some phage end up with donor bacterium DNA (tansducing phage)
6. Donor bacterium is lysed (burst) tore leased progeny phage.
7. Transducing phage binds to recipient bacterium and injects donor bacterium DNA
8. Donor bacterium DNA is incorporated to recipient bacterium DNA
102
What is the jist of conjugation?
Transfer of DNA from donor bacterium to recipient bacteria. Via direct cell to. Cell contact.
103
What is needed for conjugation to occur?
| What are examples of genes that are. Transferred via conjugation?
Cell to cell contact via a pious, requires 2 live bacteria
| Drug resistance, enzyme production, pili and fimbrae production
104
Where is the gene to produce a pilus located?
What is plasmid called?
What other genes could be on it?
What are the two types of bacteria involved in conjugation called?
What is a pilus and what are its functions?
Plasmid
F or fertility plasmid
Drug resistance, enzyme production capsules...
F+ bacteria- have a fertility. Plasmid, produce a pilus
F- bacteria- no fertility plasmid, no pilus
Hallow tube extending from. Outside of. Bacterium
Conjugation, and movement
105
What are the 3 steps in f+ x f- conjugation?
1. F+ donor bacterium attaches to f- recipient bacterium. Via pilus and two bacteria are. Drawn closer together
2. One strand of f plasmid. DNA is transferred from donor bacterium to recipient bacterium. Via pilus.
3. Donor and recipient Bacteria synthesize corresponding strand Of f Plasmid---->both f+
106
What is an Hfr cell?
| What are the 3 steps in Hfr x f- conjugation?
When the f plasmid DNA. Integrates into the main chromosome
1. Hfr (donor, has f plasmid, so f+) connects to recipient bacterium (f-) via six pilus, 2bacteria draw close together
2. DNA. Transfer begins in the middle of the f plasmid dna. Part of f Plasmid DNA and some main chromosome DNA is transferred, NEVER stay connected Long enough to transfer all of f plasmid DNA
3. At the end, Hfr still Hfr and f- still f-, but it did get some DNA and added that DNA to its existing DNA
107
What does virus literally mean?
How many have been discovered?
How many do virologists think there are?
How. Does this compare me to bacteria?
Poison
More than 5000
More than 400,000
Out. Number. Bacteria by a factor of ten
108
What is a virus?
Size?
Obligate intracellular?
Parasite?
Small, obligate, intracellular parasite
Small, need an electro microscope to see
Must. Go inside. A host cell. To replicate
Virus benefits, host cell. Is harmed
109
Do virus infect only people?
No a wide. Range. Of organisms
110
What are the three viral components?
Nucleic acid
Capsid
Envelope for some
111
Nucleic acids aka?
What are the two types?
Which ones. Single stranded which Ones double?
Viral genome
DNA-double stranded
RNA - single stranded
112
Capsid aka?
Made. Of what?
Function?
Protein coat
Capsomeres
Protect nucleic acid
113
What is an envelope?
Where and. When does it get it?
What can it have on the outside? What are their function?
Membrane that surrounds the capsid
Virus acquires this membrane from host cell during viral replication
Can have spikes which aid in penetration and attatchment
114
What are the three viral shapes?
1. Helical- spiral
2. Polyhedral-spherical
3. Complex- not helical or polyhedral
115
What term do wee use instead of reproduction for. Virus?
Why.
How does this process end?
Replication=make progeny viruses
Because. Viruses must go inside a host cell. And. Use host cell machinery to produce progeny viruses
Ends in lysis
116
What are the 6 steps in lyric viral replication?
| How long does this take and how many virus produced?
1. Attatchment-t4 and. E.coli randomly collide, receptor on e.coli binds with t4. (Specificity means virus must fit knot receptor on host cell)
2. Entry- muster DNA of t4 lists the outer membrane, peptidoglycan, cell membranes e.coli. T4 Releases and enzyme called lysozyme Weakens membrane and peptidoglycan. T4 can inject its DNA. Into e.coli. Capsid does not enter e.coli.
3-4. Synthesis- viral enzymes degrade e.coli DNA. T4 DNA Uses e.coli machinery to produce capsids and DNA (viral components)
5. Assembly-insert t4 DNA into capsid
6. Release- lysozyme completes its work on membrane And peptidoglycan. E.coli lyses releasing t4 progeny viruses. E.coli is dead.
*t4 and. E.coli b in 25 minutes, produce 100-200 new t4
117
What are the 8 steps in lyse genie replication?
| What are some induction triggers?
1. Attatchment- same as LVR
2. Entry- same as LVR
3-4. Insertion and replication- lambda DNA inserts itself into e.coli chromosome. Lambda DNA is replicated along with e.coli DNA
5. Induction- lambda DNA is excised(pops out) of e.coli chromosome when triggered.
6. Synthesis- same as LVR
7. Assembly- same as LVR
8. Release- same as LVR
Induction triggers= uv light, carcinogens, radiation
118
What are the 5 steps in animal virus replication?
| How long does it take and how many made?
1. Attachment-Animal virus and host cell randomly collide, receptor. If an. Enveloped virus, has spikes, increased Attachment.
2. Entry- direct penetration,membrane fusion, or endocytosis.
3. Synthesis- animal virus's nucleic acid uses the animal cell machinery to produce viral components (nucleic acid, capsid). Animal Virus that has RNA as nucleic acid produces reverse transcriptase (DNA---->RNA). Many drugs used for retroviruses, they target reverse transcriptase.
4. Assembly- insert viral nucleic Acid into capsid
5. Release
Replication takes 24 hours and 100,000 new virus formed
119
From the following, what kind of Viruses use it and what. Is it?
direct penetration?
Membrane fusion?
Endocytosis?
- some non-enveloped animal viruses enter This way, virus infects its nucleic acid into host cell
- some enveloped viruses enter this way. Fusion of Viral Envelope and host cell membrane, entire virus enters, capsid is removed once inside animal cell
- most enveloped viruses and some non-enveloped viruses enter this way. Virus binding to Receptor stimulates the Host cell To take The entire virus into host cell. Virus will be up coated (capsid removed) once inside animal cell.
120
What is the difference between non-enveloped virus release and enveloped virus release in animal virus replication?
Non- progeny viruses are extruded from animal host cell via exocytosis, end is lysis of host cell.
Enveloped-progeny Viruses are extruded from host cell via exocytosis and take a layer of host cell membrane envelope
121
What does latency mean?
| How do they become active again?
Some viruses can go dormant for years, decades with out any activity
They are triggered to exit latency by things like uv light, stress, infection...
122
What percent of all cancers are caused by viruses?
What strain of the human papilloma virus causes. What kind of cancer?
How does a virus contribute to cancer?
What is the multiple hit hypothesis?
15-20%
16 & 18, cervical cancer
Activates the oncogene, which control mitosis and are usually repressed "off", virus turns them "on" and you get uncontrolled cell growth.
Not just the virus causes it, could be others like...exposure to carcinogens, mutagens, uv light, radiation, genetics, life style...
123
```
What is a prion?
Made of?
Cause what?
Disease name in cows, sheep, deer and humans
Signs and symptoms?
Transmitted by?
Treatment?
How to eradicate?
```
Proteinaceous infections particles
Protein
Spongiform encephalitis- holes in brain tissue
Cows=mad cow disease, sheep=scrapie, deer= chronic wasting syndrome, humans=kuru! cj disease! fatal familial insomnia
Loss of sensory/motor, imbalance,paralyzed
Ingesting infected tissue, contact with mucous membrane of infected
No treatment, fatal
Incinerate, autoclave
124
What are two examples of nucleic acids?
```
Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)
```
125
What is the monomer of nucleic acids?
Nucleotides
126
What are the components of nucleotides?
Phosphate group, nitrogenous base, and a sugar
127
What is the sugar in DNA?
What are the nitrogenous bases? What pairs with what?
How many strands? What does to look like? How is it put together?
What does it contain?
What are the two different strands and what is the terminal group. How do they run together?
Deoxyribose
Adenine, thymine, guanine, and cytosine. A with t, c with g
Double stranded, a double helix,looks like a spiral staircase. The sides of the staircase are huge phosphate group and sugar, each step is made of two nitrogenous bases. They run anti parallel to each other
Contains he the hereditary information for the cell
5' strand has a terminal phosphate group, 3' strand has a terminal hydroxyl group
128
What is the sugar in RNA?
What are huge nitrogenous bases? What pairs with what?
How many strands?
What are the three types?
Ribose
Adenine, uracil, guanine, and cytosine. U with a, g with c
Single stranded
Messenger RNA (mRNA), ribosomal RNA (rRNA),and transfer RNA (tRNA)
129
What is a genome?
| What is a gene?
The entire genetic complement of a cell or virus
| A specific sequence of nucleotides that codes for a protein or RNA.
130
Where is bacterial chromosome found?
How much volume does it take up?
How does it fit inside the cell? What enzyme is used?
What is a plasmid?
In the cytoplasm
one third
Bacterial DNA is supercoiled with DNA gyrase
A separate small, circular loop of DNA that carries nonessential information and replicate independently
131
What is replication?
When does it happen?
What is semi-conservative replication?
Copying DNA
Before binary fission
DNA replication where DNA is traced. Both DNA strands serve as a template to produce a new DNA strand,we end up either copies of the DNA,reach copy is half originally a and half new DNA
132
What direction does replication occur?
What enzyme unwinds and uncles the DNA? What is needed for this step to occur?
What holds the two DNA strands apart?
What enzyme replicates the DNA?
Bi-directionally from a single point
Helicase,ATP
Single-stranded proteins
DNA polymerase
133
I what direction does the DNA polymerase replicate the DNA?
What is the leading strand?
What is the lagging strand? What are the fragments called? What knits these back together?
What proof reads the replication?
5'--->3' direction
The 5'-3' strand that is replicated continuously
The 3'-5' strand replicated discontinuously on fragments called Okazaki fragments, which are then knitted together with DNA ligase
DNA polymerase proof reads
134
```
What is the central dogma of biology?
What is a dogma?
What is at transcription?
What is translation?
Which genes are transcribed and translated
```
Flow of information
A principle or dry of principles laid down by an authority as incontrovertibly true
Process of DNA being converted to mRNA
Processing mRNA being converged to protein
Only the genes that they need to products of
135
Where does transcription take place in prokaryotes? In eukaryotes?
How many DNA strands serve as a template on transcirption?
What unzips DNA?
What is the promoter?
What enzyme moves along the DNA strand that serving as the template and adds complementary nucleotides and build the mRNA strand?
Where does transcription end?
```
Cytoplasm and nucleus
Only one of the DNA strands
Helicase
The gene that transcription starts at
RNA polymerase
At the end of the gene
```
136
Where does translation take place? What is the site?
Who has smaller ribosomes? Eukaryotes or prokaryotes?
What will bring the amino acids?
How is mRNA read?
What is a codon? What does it specify?
What is an anticodon?
What gets the amino acid in the right order?
Cytoplasm at the ribosome
Prokaryotes 30s and 50s (as opposed to eukaryotic 40s and 60s)
tRNA
The ribosome moves along the mRNA 3 nucleotides at a time
3 nucleotides on mRNA that specifies for an amino acid
3 nucleotides on tRNA
Complementarity between the codon on mRNA and the anticodon on tRNA
137
How does the antibiotic rifampin work?
Blocks RNA polymerase preventing transcription
138
How do the antibiotics streptomycin and tetracycline work?
They bind to the subunit of prokaryotic ribosomes preventing translation
139
What is degeneracy of the genetic code?
What does this mean for the cell?
What position can a mistake be In for it to still code for the same amino acid? What is this position called?
Redundancy, more than one codon encodes for the same amino acid.
You can make a mistake and get away with it.
3rd position or wobble position
140
What is genetic engineering?
| What is recombinant DNA? What enzymes are critical in producing this? What is this?
Alteration of the genetic material in a organism to change its traits or to allow the organism to produce a biological product.
DNA spliced together from two or more organisms. Restriction enzymes which Cuts DNA after a specific nucleotide sequence
141
What can restriction enzymes be used for?
To cut out a human gene, isolate it and give it to a bacteria via transformation.
DNA fingerprints
142
Where are DNA fingerprints used?
What is RFLP?
What is gel electrophoresis?
Crime scenes and paternal testing
Restriction fragment length polymorphism, or where samples are digested pow other a restriction enzyme and because the order of nitrogenous bases is unique, a each persons DNA will be cut into a different number of fragments
Separates the DNA fragments according to size and creates a pattern
143
What is PCR? And what is it used for?
Polymerase chain reaction to multiply DNA in vitro
| Used in crime scene analysis if the crime scene sample is too small for further testing, also for diagnostic testing
144
What is gene therapy?
What is a vector?
What is the most common vector?
A technique for correcting defective genes responsible for disease development. Where a normal gene is inserted into the genome to replace abnormal, disease causing genes.
A carrier molecule used to deliver the gene to the a stints target cell
A virus
145
What is the direct introduction Gene method of gene therapy?
Liposome method?
47the chromosome method? What is the problem?
Directly out therapeutic DNA into target cells.
An artificial lipid sphere with a aqueous core carries the therapeutic DNA,able to pass through cell membrane
Chromosome would exist with cells other chromosomes, it's too big to get into the nucleus of the cell
146
What factors have kept gene therapy from becoming an effective treatment for genetic disease?
What must happen?
What prevents this?
1. Introduced DNA must remain functional NAND the cells contains the therapeutic DNA must be long lived and stable
2. Rapidly dividing attire of cells, immune system, virus might recover ability to cause disease
147
What is the best for gene therapy?
Mutations in a single gene
148
What is the human genome project?
| In what three ways have researchers deciphered the human genome?
The international, collaborative research program whose goal was the complete mapping and understanding of al the genes of human beings
Determining the order of all the bases of our DNA, makjg maps that show locations of fends, and linkage maps where inherited traits can be tracked over generations.
