Chapters 4 & 5 Medmicro Review

What does classification and taxonomy provide information about or contributes to what?

- identification of unknown species

- study of evolution

- trace origins of bacteria

- enable communication among scientists regarding same/diff. microbes

What stabilizes the cell wall of mycoplasma?

- sterols

Describe the cell membrane of a prokaryotic cell.

- phospholipid bi-layer

- embedded proteins

What are some functions of the cell membrane?

- package nutrients

- discharge waste

What makes the cell wall structure of Mycobacterium and Nocardia different?

- gram-positive cell wall structure with lipid mycolic acid

- mycobacterium has special wax layer

List the different appendages you would find on bacteria.

- flagella

- periplasmic flagella

- fimbriae

- sex pili

What type of flagella do Spirochetes have?

periplasmic

Define fimbriae.

- hair-like bristles

- function: adhesion to other cells/surfaces

What is the job of pili in bacteria?

join bacteria cells for DNA transfer (conjuation)

Define peritrichous.

flagella dispersed over surface

The difference in the outcome of Gram staining is determined by ________.

cell wall

What is the job of ribosomes?

synthesize proteins

What is chemotaxis?

- movement of an organism in response to a chemical stimulus

- towards or away from cell

What is the structure that allows chemotaxis?

flagella

What protects the cell from rupturing if placed in a hypertonic environment?

- cell wall

- prevents lysis due to change in osmotic pressure

What is the role of a capsule?

- blocks phagocytosis

- becomes more pathogenic

Where would you find peptidoglycan?

cell wall of bacteria

What is the role of inclusions?

store nutrients for usage when environmental sources are depleted

Gram positive bacteria have what in their cell wall?

- peptidoglycan

- teichoic acids

- lipoteichoic acid

- mycolic acids

- polysaccharides

Gram negative bacteria have what in their cell wall?

- lipopolysaccharide (LPS)

- lipoprotein

- peptidoglycan

- porin proteins

Which microorganisms have mycolic acid in the cell wall?

- mycobacterium

- nocardia

Endotoxins are released from the cell wall of Gram ______ bacteria.

negative

Acid-fast staining occurs in Gram _____ bacteria.

positive

Can endotoxins stimulate fever?

yes, can stimulate fever

Can endotoxins cause shock?

yes, can stimulate shock

Can endotoxins be involved in typhoid fever and some meningitis? *

yes *

Are endotoxins specific cell wall lipids?

- yes

- liquid portion of LPS (outer membrane)

Where would you find lipopolysaccharides?

gram - negative cell wall

What happens in the periplasmic space?

- site of metabolic reaction

- what enter and leaves the cell wall

Is periplasmic space found in gram negative or gram positive bacteria?

both

Where do you find the bacterial chromosome?

nucleoid

What is the nucleoid?

where chromosome reisides

What is cytoplasm?

dense, gelatinous solution

Are plasmids essential to bacterial growth and metabolism?

no, not needed for bacterial growth and metabolism

What are magnetosomes composed of?

iron oxide

What do magnetosomes do?

used for navigation

What is the function of endospores?

protect genetic material (whole cells) during harsh conditions

The heat resistance of endospores (spores) has been linked to what chemical and mineral?

- calcium

- dipicolinic acid

Are endospores metabolically active?

- inactive

Are endospores living structures?

- are living structures

Why are endospores important?

protect during harsh condition

What bacteria can produce endospores?

- bacillus

- sporosarcina

- clostridium

List the bacterial shapes.

- coccus

- bacillus

- vibrio

- branching filaments

Define coccus.

spherical

Define rod/bacillus.

rod

Define vibrio.

gently curved comma

Define branching filaments.

branching like tree

What is a tetrad?

groups of 4

List some characteristics of biofilms.

- cause disease

- eukaryotic (algae, protozoa, fungi, bacteria)

- difficult to eliminate

- can be found on non living and living

- scum in toilet/shower stall

What is an important indicator of evolutionary history of a microbe?

sequence of rRNA

Give an example of a thermotogae ( a microbe).

thermophilic halophil

What type of walls (Gram + or Gram -) does Firmicutes have?

gram - positive

What type of staining would you need to use on Actinobacteria?

acid staining

Why do you use acid staining on Actinobacteria?

waxy acid fast cells

Describe proteobacteria?

- gram negative

- rickettsia + e. coli

- ARE NOT ARCHAEA

Define phylum chlamydia.

lack ability to grow and metabolise by itself (damage host cell)

Define phylum chlorobi.

- green sulfur bacteria

- photosynthesize and metabolize sulfides

Define phylum cyanobacteria.

found in aquatic habitats and soil

Define phylum proteobacteria.

- myxobacteria

- gliding

- fruit slime bacteria

What is the physical description of coccobacillus.

- short

- plump

What is the definition of Sarcinae?

- cuboidal packet

- sets of 8 - 64

Define lophotrichous flagella.

small bunches emerging from the same site

List some characteristics of the slime layer.

- protects from dehydration and loss of nutrients

- allows cells to participate in biofilms

- can be easily washed off

- contributes to pathogenicity

- type of glycocalyx

What are some important characteristics of plasmids?

- free, small, circular, double - stranded DNA

Where would you find Archaea?

extreme habitats

What organism(s) cause Rocky Mountain Spotted Fever?

rickettsia rickettsii

What organism(s) cause Endemic typhus?

rickettsia typhi

What organism(s) cause eye diseases like blindness and an STD?

chlamydia trachomatis

What organism(s) cause Syphillis?

treponema pallidum

What organism(s) cause Q-fever?

coxiella

List characteristics of living things.

- replicate

- reproduce

- respond to stimulus

- does not need cell boundary

What makes it possible to differentiate the members of the following genus?

acid fast staining

Define sporulation.

endospore formation

Define germination.

cell returns to vegettive growth

Why would members of Bacillus and Clostridium create spores?

- withstand extreme conditions

- ex: temp. change/lack of nutrients

Put the following microorganisms in order from smallest to largest:

- Ebola virus
- Staphylococcus cell
- Red blood cell
- Rhinovirus
- Squamous epithelial cell
- Yeast

1. Rhinovirus

2. Ebola virus

3. Staphylococcus

4. Yeast

5. RBC

6. Squamous epithelial cell

What unit is most appropriate for measuring the size of bacteria?

micrometer

Which two domains are the most closely related?

- archaea

- eukarya

How can we differentiate between Bacteria and Archaea?

chemical makeup of cell wall

What is the term used for a microorganism that loves an environment with high salt content?

halophiles

What domain would you classify an organism that loves an environment with high salt content under?

archaea

If you are infected with E. coli, you most likely contracted that organism through what?

fecal/oral transmission

Where does E. coli tend to colonize?

intestinal tracts

What is quorum sensing?

chemical communication with each other

Give an example of quorum sensing.
---look in your textbook

one bacteria releases a substance and tells other bacteria

Define pleomorphism.

drastic variation in cell shape and size in a signle species

What microorganisms are protists?

- protozoa

- algae

Which eukaryotic organelle most resembles a bacterial cell?

mitochondria

How do eukaryotic and prokaryotic flagella differ?

eukaryotic have:
- microtubules

- cilia

Where do you find Cilia? Do not think area of the body...think microbiology.

protozoa

Where do you find Chitin?

cell walls of fungi

You would typically not find cell walls in what group of microorganisms? Think of the 6 (algae, protozoa, helminths, bacteria, virus, fungi)

- protozoa **

- helminths

- virus

Where does ribosomal synthesis RNA occur?

nucleolus

What are histones?

proteins associated with DNA in nucleus

According to the endosymbiotic theory, how did precursor eukaryotic cells come into existence?

protozoa, animals: aerobic prokaryotic cells ingested

How did precursor eukaryotic cells gained photosynthetic ability?

algae, plant: cyanobacteria ingestion

What is the glycocalyx?

outermost cell boundary

What is the function of glycocalyx?

- adherence

- protection

- signal reception

Glycocalyx is composed of ___?

polysaccharides

What can be found in eukaryotic cells but not prokaryotic cells. Look at Table 5.4

- true nucleus

- nuclear evelope

- mitosis

- lysosomes

- organelles (golgi apparatus, ER, mitochondria)