BIO 251 Final Exam Quizlet

Known for discovering microorganisms and creating the first simple lens microscope

Antony Van Leeuwenhoek

Known for the swan-necked flask experiment, which disproved spontaneous generation

Louis Pasteur

Known for the four postulates that proved the role of microorganism in causing disease

Robert Koch

Known for defining archaea (Three domain system) and phylogenetic taxonomy on 16S RNA

Carl Woes

Known for creating the book Micrographia, the compound microscope, and the term cell from observing cork.

Robert Hooke

Frederick Griffith infected mice with a combination of dead encapsulated and live nonencapsulated bacteria. Why did the mice die?

The two bacterial strains shared plasmids.

Conjugation occurred between the two bacterial strains.

The nonencapsulated bacteria acquired the gene for capsule production via transformation.

The nonencapsulated bacteria mutated, thus acquiring the ability to make a capsule.

The encapsulated bacteria were revived in the mice and caused a lethal infection.

The nonencapsulated bacteria acquired the gene for capsule production via transformation.

Who discovered penicillin?

Alexander Fleming

Who upscaled the production of penicillin?

Florey and Chain

What did Dorthy Hodgkins win the Nobel Prize for?

Determining the structure of penicillin using x ray crsytallogrpahy

Stain enhances the ___________ of microbes

contrast

What are the 4 steps of gram staining?

1. Crystal violet

2. Gram's iodine

3. Alcohol

4. Safranin

The gram stain reflects the differences in what chemical structure of bacteria?

Cell walls

What color do gram negative bacteria stain?

pink

What color do Gram-positive bacteria stain?

purple

T or F:

Gram-positive bacteria are associated with a thick layer of peptidoglycan and a more porous cell wall

True

What do basic dyes stain?

(positive) The cell

What do acidic dyes stain?

(negative) The background

Do capsule stains, stain the background or cell?

Background

T or F

Generally, Viruses can not be seen with microscopes

True

How do species and strain differ?

Species is a subset of a genus, Strain is a subset of species

Which of the following is a structural feature of all prokaryotic cells?

a.) Nucleus

b.) Peptidoglycan cell wall

c.) Mitochondria

d.) Endoplasmic reticulum

b.) Peptidoglycan cell wall

Prokaryotic cells have _____S ribosomes

70

Eukaryotic cells have ______S ribosomes

80

What type of bacteria contain the peptide interbridge?

Gram postive

T or F

Only Gram-negative bacteria contain LPS (Lipopolysaccharide)

True

T or F: viruses are acellular

True

Can viruses reproduce on their own?

No, they must hijack a living cell and reproduce through that cell.

What are viruses made up of?

RNA or DNA sometimes enveloped in a capsid but not always

What do plasmids code for?

Resistance to antibiotics

How can viruses be transmitted?

a.) enteric

b.) respiratory

c.) zoonotic

d.) Arboviruses

e.) sexually transmitted

f.) all of the above

f.) all of the above

What are some common genera that produce endospores?

anthrax, gangrene, botulism, tetanus, c-diff

Why are endospores difficult to eradicate?

They have a high resistance, are found virtually everywhere, and can remain dormant for many years

Transformation

Uptake of DNA from the environment

Transduction

bacteriophage infects host bacteria, gains new genes

Conjugation

Transfer of plasmids through pilus

In the case study from class, Methicillin-resistant Staphylococcus aureus (MRSA) strains had acquired virulence factors via what mechanism?

transduction

mutation

reversion

conjugation

transformation

transduction

What does it mean when a bacterial cell has undergone lysogenic conversion?

a.) phage has been replicated in the bacterial cell

b.) The phage has simply infected the cell

c.) the phage has lysed the cell

d.) the bacterial cell has acquired several different phage

e.) the genome of a phage has been integrated into the genome of the bacteria

e.) the genome of a phage has been integrated into the genome of the bacteria

What microscope is used to view viruses?

electron microscope

Explain the cholera toxin example of transduction

Cholera produces toxin because phage gives it the DNA necessary to produce the toxin

Explain the Staphylococcus case study

The diabetic patient had necrotizing fasciitis

S. aureus was found to be antibiotic resistant because of transduction

In the case study from class, Methicillin-resistant Staphylococcus aureus (MRSA) strains had acquired virulence factors via what mechanism?

transduction

mutation

reversion

conjugation

transformation

transduction

What are the steps of the replication of viruses?

attachment, penetration, uncoating, replication, assembly, and release

What are the categories of bacteria based on temperature tolerance

Psychrophiles

Psychrotrophs

Mesophiles

Thermophiles

Hyperthermophiles

Where might mesophiles be found?

On a door handle

Where can psychrophiles be found?

In the fridge

Obligate aerobes

Require oxygen

Obligate anaerobes

Grow without oxygen

Facultative anaerobes

Grow best with oxygen but can also grow without it

Microaerophile

Requires a little oxygen

Aerotolerant anaerobe

grows equally well with or without oxygen

Neutrophiles pH

5-8

Acidophiles pH

below 5.5

Alkaphiles pH

above 8.5

T or F

Highly acidic and alkaline environments inhibit bacterial growth

True

What are the phases of growth?

Lag phase

Log phase

Stationary phase

Death phase

Phase of prolonged decline

What microbes are the most difficult to eradicate?

Endospores

What are the methods of sterilization?

Autoclave, filtration, radiation, ethyl oxide, and 2% glutaraldehyde

Sterilization

Complete removal or killing of all vegetative cells, endospores, and viruses

Aseptic technique prevents contamination of the ______________ field

sterile

what do antibiotics target in prokaryotic

cells

The cell wall

What are the major categories of antibiotics?

Cell wall synthesis inhibitors

Protein synthesis inhibitor

DNA / RNA synthesis inhibitor

Metabolic pathway inhibitor

Plasma membrane inhibitor

How do bacteria develop resistant to antibiotics

Through horizontal and vertical gene transfer

What factors contribute to the development/spread of antibiotic resistance

Not taking the whole bottle

Misuse of antibiotics

Explain how antibiotics are effective for treating infectious diseases

They kill bacteria or prevent them from reproducing and spreading

Why are antibiotics not effective against viruses?

Viruses are nonliving. They have no targets for antibiotics to target

signs

Observable/ measurable

symptoms

feelings

Nosocomical Infections typically occur

In those who are in hospitals

Latrogenic Infections are the result of

surgery

What is virulence

The degree or amount of disease/damage

What are the four steps in pathogenesis

1. Exposure/contact

2. Attachment

3. Invasion

4. Infection and damage to host

What are the steps of the development of infectious disease?

Incubation

Prodromal

Illness

Decline

Convalescence

Describe endotoxins

Gram negative and lipopolysaccharides

Describe exotoxins

Proteins, toxic in low doses

Explain Koch's postulates

Bacteria that cause disease in one mouse can be cultured and given to another mouse, causing the same disease

innate immunity

nonspecific and typically present at birth. Associated with physical and mechanical barriers: Skin, hair, coughing, tears, sneezing, etc

adaptive immunity

Specific and develops over time. Associated with T and B cells

What are antibodies?

proteins created by B cells

What is the main function of antibodies?

To inactivate toxins

How does vaccination work to protect people from infectious diseases

Vaccines train immune cells to remember virus for the real time they get infected

Griffith's postulates show what type of horizontal gene transfer?

transformation

Gastritis

inflammation of the stomach

Enteritis

inflammation of the intestinal mucosa

gastroenteritis

inflammation of both the stomach lining and intestinal lining

Hepatitis

inflammation of the liver

colitis

inflammation of the colon

Dysentery

Damage to the epithelial cells of the colon causes bleeding and excess mucus, and watery stools

Explain how S. aureus is responsible for food poisoning

exotoxins were ingested

What are the characteristics of H. pylori

Gram-negative, microaerophile, multipolar flagella

How does H. pylori survive in the stomach

produces urease which breaks down urea, neutralizing the environment

How does H. pylori contribute to peptic ulcer formation?

Decrease mucus production

What are the characteristics of C. diff

Gram positive, obligate anaerobe, produces endospores

Who is most affected by C. diff infections?

Hospital patients on antibiotics, elderly, and immunocompromised

T or F

C diff is nosocomial

True

What are the ways in which C. diff can be treated/prevented?

- Stop antibiotics

- Electrolyte replacement

- Fecal transplant

- Hand washing

- Wearing gloves

- Disinfectants

What TWO medications can be given to treat C. diff

Metronidazole and vancomycin

Which structure is found only in Gram-negative bacteria?

A) Thick peptidoglycan layer

B) Teichoic acids

C) Outer membrane

D) Endospores

C) Outer membrane

What is the major structural difference between prokaryotes and eukaryotes?

A) Ribosomes

B) Cell wall

C) Nucleus

D) Cytoplasm

C) Nucleus

Which component is always found in all viruses?

A) Envelope

B) DNA and RNA

C) Capsid

D) Ribosomes

C) Capsid

How do viruses replicate?

A) Binary fission

B) Budding

C) Using host cell machinery

D) Meiosis

C) Using host cell machinery