chapter 4

Question 1

What are characteristics that every cell has?

Answer 1

• Every cell has a cell membrane
• Every cell has ribosomes
• Most have cell walls

Question 2

What are the main differences between prokaryotic v. Eukaryotic cells

Answer 2

Prokaryotic Cells

• ​everything floating in the cytoplasam
• DNA in nucleolus
• Eukaryotic Cells
• Has membrane bound organelles
• DNA in nucleus

Question 3

What does the cell envelope consist of?

Answer 3

• cell membrane
• cell wall (usually)
• Glucocalyx (the slimey layer around the cell) (sometimes) –> 1) capsule 2) slime layer

Question 4

• The bacterial cytoplasmic membrane (bilipid layer)
• Where are the hydrophillic heads?
• Where are the hydrophobic heads?

Answer 4

• heads protect the hydrophillic heads protects hydrophobic tails. hence, the heads are on the outside
• inside of the membrane are the hydrophobic

Question 5

What is simple diffusion?

what are the characteristic of particles that undergo simple diffusion?

Answer 5

Something that goes straight through

• small things, lipid soluble, little charge

Question 6

What is passive transport (diffusion)?

Answer 6

High concentration to low concentration (doesn’t require energy)

Question 7

What is active transport?

Answer 7

requires energy input to go fromw low concentration to high concentration

Question 8

What is the bacterial cell wall consisted of?

Answer 8

-composes of peptidoglycan –> nam and nag strands linked together

Question 9

Characteristics of gram-positive bacteria

Answer 9

• gram positive has thick layer of peptidoglycan
  *

Question 10

Characteristics of gram-negative bacteria

Answer 10

• gram negative has a thin layer of peptidoglycan in addition gram negative has outter and inner lipid layer (peptidoglycan in the middle) and corenscprotein channels move stuff
• resistant to antibiotics
• lipopolyssachride (attached to outter membrane) (endotoxin) is released when a cell dies and makes gram negative bacteria viligent
• resistant to certain antibiotics –> thin layer of peptidoglycan = pump out easily

Question 11

Where does the lipolysaccharide (aka Endotoxin) get variation?

Answer 11

We get the variation on the O- antigen

Question 12

what color are the gram-negative bacteria?

What color are the gram-positive bacteria?

Answer 12

• Pink (rod shaped- bacillus)
• purple (circle-cocci)

Question 13

What are the effects of endotoxin?

Answer 13

• you get coagulation (blood clotting in vessels)
• hypotension (vessels open) low blood pressure–>death
• inflamation and fever
• intervascular vasculation

Question 14

what type of bacteria is myobacterium ?

• is it gram positive or negative?
• what is special about it’s cell membrane?

Answer 14

it is acid-fast bacteria

• weak gram positive staining but it doesnt work well
• its cell membrane has mycolic acid which makes it waxy, therefore we use the steaming procedure to melt the wax so water can get into it

Question 15

Mycoplasma

• What does it lack?
• what does it contain in its cell membrane?

Answer 15

Mycoplasma

• it lacks a cell wall
• to compensate for it’s cell wall deficency

Question 16

What are biofilms?

Answer 16

microorganisms that secrete capsules or slime layer (gelatenous substance that microbs come together and join to make) this in turn creates layers of microbes that is hard to get rid of

Question 17

Do all bacteria have glycocalyx

Answer 17

no; only some

Question 18

what are the external structures

Answer 18

• endospores (get ejected from cell)
• Appendages: flagella, pili

Question 19

Describe the endospore cycle

Answer 19

Endospores are formed by vegetative cells in a process called sporulation.
Sporulation is initiated when conditions for growth of the vegetative cells become
harsh (for example, when water or an essential nutrient is limiting). Sporulation is
a complex process involving as many as 200 genes. These genes are activated by
an environmental trigger, causing sporulation of the cell. The steps leading to
endospore formation result in the creation of a dry, metabolically inert and extremely
resistant endospore from a moist, metabolically active vegetative cell. Extensive
sporulation studies have been done on Bacillus subtilis, and this microbe can
perform the entire sporulation process in about eight hours.

Endospores can remain dormant for many years, but, when conditions allow, they
can convert back to vegetative cells fairly rapidly. This process is called germination,
and it involves three steps: activation, germination and outgrowth. Activation
can be accomplished by heating freshly formed endospores at a high temperature.
Activated spores can then be conditioned to germinate by placing them in the
presence of specific nutrients. During germination, the spore becomes less resistant.
This stage includes loss of calcium dipicolinate and degradation of small acid-soluble
spore proteins. The final step is outgrowth, which involves swelling due to water
uptake and the synthesis of new DNA, RNA and proteins. The cell grows out
of the broken spore coat and eventually resumes normal cell function. The
vegetative cells continue to grow and divide until harsh environmental conditions
once again trigger the sporulation process.

Question 20

spore coat is resistant to what….

Answer 20

drying, heat, chemicals

Question 21

what are the 4 types of flagella arrangements

Answer 21

• 1 flagella: monotrichous
• 2 flagella: lophotrichous
• flagella all over over: peritrichous
• flagella on polar ends: amphitrichous

Question 22

what are pili used for?

-what are plasmids

Answer 22

they are appendages to connect bacteria and share DNA (also called conjugation)

• extrachromosomal DNA

Question 23

S=_______ units

Answer 23

spheburg units

Question 24

equation for prokaryotes:

__s+__s= __s

Equation for eukaryotics:

__s+__s=__s

Answer 24

equation for prokaryotes:

50s+30s= 70s

Equation for eukaryotics:

60s+40s=80s

–> selective toxicity