Microbiology Exam I

List the types of Microorganisms

1. Bacteria

2. Archaea

3. Fungi

4.Protozoa

5.Algae

6. Viruses

Rules for nomenclature

1- Italicized or Underlined

2. The genus is capitalized, and the specific epithet is Lowercase.

What did Edward Jenner discover?

Inoculated a person with cowpox

virus, who was then protected from smallpox

vaccination

What are Antibiotics?

Who discovered the first antibiotic?

Antibiotics: are chemicals produced by bacteria and fungi that inhibit or kill other microbes

Alexander Fleming

In a ------------ microscope, the image from the objective lens is magnified again by the ocular lens

compound microscope

Staining the background instead of the cell is

called ------

Negative staining

------- is the ability of the lens to distinguish two points

Resolution

Special Stain is used to

Used to distinguish parts of microorganisms

What are the types of differential stains? And

the use of each.

A. Gram Stain: Classifies bacteria into gram positive or gram-negative

B. Acid - Fast stain: Binds only to bacteria that have a waxy material in their cell walls, which is not decolorized by acid- alcohol Used for the identification of

- Mycobacterium

- Nocardia

What are the two types of Glycocalyx and what is its function

Capsule

-Slime layer

Function: contribute to virulence (prevent phagocytosis, helps form biofilms)

-------- I have a hair like structure and I allow for attachment.

Who am I?

Fimbriae

Describe Flagella structure and function

Structure: Filaments, Hook, and basal body

Function: Movement (Taxis)

What is another name of Axial filaments and where do we find them?

Also called endoflagella

- Found in spirochetes

LPS contain:

1.

2.

3.

1. O polysaccharide antigen

2. Core polysaccharide

3. Lipid A is: an endotoxin embedded in the top layer

Define Pasteurization

Pasteurization is the application of a high heat for a short time

Define Biofilm? Its Function?

Biofilm: is a matrix formed by bacterial cells which allow them to

attach to surface as well as to other bacterial cells

- Biofilms can cause infections and are often resistant to antibiotics

------------ I am involved in DNA transfer from one cell to another

Who am I ?

Pili

What does the endosymbiotic theory say?

It states that mitochondria and chloroplasts in eukaryotic cells were once bacteria that were engulfed by larger bacteria.

What is the path of the light from bottom to top?

Illuminator

Condenser

Specimen

Objective lens

Ocular lens

Each of the following statements concerning the gram-positive cell wall is true EXCEPT

it protects the cell in a hypertonic environment.

which of the following have a cell wall?

Fungi

fimbriae and pili differ in that

pili are used for transfer of DNA and motility.

The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction.

True

cells placed in a hypotonic solution tend to lose water due to osmotic pressure.

False

spheroplasts, protoplasts, and mycoplasms are bacterial cells without cell walls.

True

spirochetes move by means of

axial filaments

which of the following structures allows a cell to survive adverse environmental conditions?

caspule

prokaryotic ribosomes are composed of two subunits of what sizes?

30S + 50S

gram negative outer membrane consists of all of the following except

lipotechoic acid

Lipid A is an

endotoxin

The DNA found in most bacterial cells:

Is circular in structure

Which of the following mechanisms will be used by a cell to move a substance from a lower to a higher solute concentration?

Active transport

When rod-shaped bacteria are arranged in chains it is called:

Streptobacillus

The cell wall around a prokaryote is to help create and maintain structure and aid in cellular respiration.

True

In a hypertonic solution, what would happen to a bacterial cell?

shrink

75% of the microorganisms are of which of the following?

Prokaryotic cells, chloroplasts and mitochondria

Which of the following organelles most closely resembles a prokaryotic cell?

Mitochondrion

Prokaryotic cells might have all of the following structures, EXCEPT FOR:

Cilium

Bacteria with small bunches of flagella emerging from the same site are said to be:

Lophotrichous

Which statement about bacterial plasma membranes is NOT true?

Contains cholesterol

The process of endospore formation is sporulation, while the process of an endospore growing into a vegetative cell is:

Germination

Which type of cellular transport uses transport proteins and moves substances from an area of high concentration to an area of low concentration?

Facilitated diffusion

What unit of measure is most appropriate for expressing the size of bacteria?

Micrometer

Which of the following is used as a mordant in staining procedures?

Iodine

The cell wall structure of Mycobacterium and Nocardia differs from gram-positive bacterial cell walls because it:

All of these choices are correct

Gram-negative bacteria have a thick peptidoglycan layer in their cell walls.

False

Facilitated diffusion is different from simple diffusion because facilitated diffusion:

Requires transporter proteins

The terms "run" and "tumble" are generally associated with:

Cell wall fluidity

Most prokaryotic cells reproduce:

By binary fission

Assume you stain Bacillus by applying malachite green with heat and then counterstaining with

safranin. Through the microscope, the green structures are

endospores

Pasteur used a swan-neck flasks, because he knew that:

living microorganisms contaminating the flask would be trapped in the neck

A virus measures 100 nm in length. What is its length in μm

0.1 μm

All of the following are true about Biofilms except

Biofilms formed on medical devices such as catheters do not cause infections

Which of the following describes a microorganism able to cause disease

pathogen

Your patient has a bacterial infection and you need to decide which antibiotic to prescribe. Which staining technique will you use?

Gram stain

Which of the following correctly traces the path of light through the compound microscope?

light source; condenser; specimen; objective lens; ocular lens.

Microorganisms are involved in

All of the answer choices are correct.

Which of the following places the steps of the Gram stain in the correct order? 1-Alcohol-acetone 2-Crystal violet 3-Iodine 4-Safranin

2-3-1-4

if you wanted to see internal structures of live cells, what would you use?

phase-contrast microscope

The three domains of life are Bacteria, Archaea, and Eukarya.

True

Which of the following is NOT equal to 10 mm?

1000 μm

You are studying the surface of a biofilm on a glass slide. Which microscope will you use?

scanning acoustic microscope

Which of the following pairs is mismatched?

nigrosin - endospore stain

yeasts are different from Helminth because they

They are single-cell

Which physician is first associated with the use of chemical disinfectants to prevent wound infections ?

Lister

Each of the following organisms would be considered a microbe EXCEPT

ticks

___________ is not part of the four-kingdom system

Bacteria

The Koch's postulates is used in the__________

determination of the cause of a disease by scientists studying disease transmission.

You are studying a gram-negative bacteria and decided to do a Gram stain. After adding the alcohol, what is the color of the bacteria at this point?

colorless

A scientist studying helminths is working with prokaryotes.

False

why do we use a mordant in the staining process?

prevent the crystal violet from leaving the cells.

What structure does light pass through after leaving the specimen in a compound light microscope?

objective lens

Archea

Prokaryotic

Lack peptidoglycan

pseudomurein cell walls

Extreme environments

Fungi

Eukaryotes

Chitin cell walls

Absorb organic molecules for energy

Protozoa

Eukaryotes

Absorb or ingest organic molecules

Motile via pseudopods, cilia, or flagella

Free living or parasitic

Algae

Eukaryotes

Cellulose cell walls

Photosynthesis for energy

Produce oxygen and carbohydrates

Viruses

Acellular

RNA or DNA core

Core surrounded by protein coat

Replicated in a living host

Multicellular Animal Parasites

Eukaryotes

Multicellular animals

Not just microorganisms

flat and roundworms called helminths

4 Kingdoms of Eukarya

protists, fungi, plants, animals

Infectious Diseases

when a pathogen overcomes a host's resistance and disease results

Biofilms

Microbes attach to solid surfaces and grow in masses. Can grow on teeth, rocks, etc. Can cause infections and be antibiotic resistant.

Normal microbiota

prevents growth of pathogens. produce growth factors. provide resistance.

biotechnology

the use of microbes for practical applications, such as producing foods and chemicals

Recombinant DNA technology

enables bacteria and fungi to produce a variety of proteins, vaccines, and enzymes

Fermentation

the microbial conversion of sugar to alcohol in the absence of air

smear

a thin film of a material containing microorganisms spread over a slide

basic dye

the chromophore is a cation

acidic dye

the chromophore is an anion

mordant

may be used to hold the stain or coat the specimen to enlarge it

gram positive

bacteria have thick peptidoglycan walls

gram negative

have thin peptidoglycan walls

capsules

are a gelatinous covering that do not accept most dyes

endospore staining

resistant dormant structures inside some cells

Primary stain: malachite green, usually with heat

Counterstain: safranin

flagella staining

mordant and carbolfuchsin

Prokaryote

one circular chromosome

no histones

no organelles

Eukaryote

paired chromosomes

histones

organelles

polysaccharide cell walls

mitosis

prokaryote cell shapes

bacillus (rod shaped)

coccus (spherical)

spiral (spirillum, vibrio, spirochete)

star shaped

rectangular

arrangements

diplo (pairs)

staphylo (clusters)

stepto (chains)

tetrad (groups of four)

sarcinae (groups of eight)

glycocalyx

external to cell wall

made of polysaccharide and or polypeptide

capsule or slime layers

prevent phagocytosis

flagella

made of flagellin

filament, hook, basal body