Microbial Cells structure And Function

Question 1

Two major differences between prokaryotes and eukaryotes

Answer 1

• prokaryotes are generally much smaller
• eukaryotes contain numerous compartments called organelles

Question 2

Can the size of both cell types vary significantly

Answer 2

Yes - extreme example is a prokaryotic cell (epulopiscium )is larger than a paramecium (eukaryote)
-epulopiscium is millions of times larger than mycoplasma (a bacterium)

Question 3

Surface area to volume ratio

Answer 3

-part of cell size and growth
Affects how quickly cells exchange nutrients and wastes with their environment
-larger SA/V ratio means that they grow more quickly since they are smaller
-small cells can generally grow and reproduce e more quickly
-smaller size and less complexity means less time and energy needed to replace the cell

Question 4

Membrane bound compartments

Answer 4

• the fundamental difference between properties and eukaryotes is the presence of membrane bound compartments
  -promoting cells do not have membrane bound compartments
  -

Question 5

Morphologies of prokaryotes

Answer 5

-come in multiple different shapes and sizes
- historically morphology has been important for naming and identifying bacteria
-shapes dictates by number of factors

Question 6

What is shapes dictated by in prokaryotes

Answer 6

Cell wall structure, cell growth and division and cell differentiation

Question 7

Cocci

Answer 7

-spheres
-staphylococci (staph aureus)
-streptococci (strep pyogenes)
-Diplococci (messers gonorrheoae)

Question 8

Bacilli

Answer 8

Rods
-salmonella enterica

Question 9

Vibrio

Answer 9

-comma shaped
-vibrio cholerae

Question 10

Helical

Answer 10

-helicobacter pylori

Question 11

Spirochetes

Answer 11

-squiggles
-borrelia burgdoferi

Question 12

Appendages/budding

Answer 12

Caulobacter cresentus

Question 13

Filamentous

Answer 13

-thin messy
- chloroplasts aurantiacus

Question 14

Why different cell morphologies

Answer 14

-nutrient access/uptake
-motility
-attachment to surfaces
-formation of biofilms
-interactions with other microbes and or eukaryotic host cells

Question 15

Monomorphic

Answer 15

-one shape
-observed in most pure cultures of bacteria

Question 16

Pleomorphic

Answer 16

Multiple different morphooogies for the same bacterium

Question 17

What causes different morphologies and changes of morphologies

Answer 17

• differentiation into different cell types or spore formation
  -altered morphology in response to environment cues
  -altered morphology due to mutation

Question 18

Example of different morphologies at different stages of growth

Answer 18

-arthrobwxter crystallopoietes
-grows as rod during logarithmic phase
-becomes a coccus in stationary phase (slow to no growth)