Prokaryotic Cell Biology

Front 1

Name the 7 features of prokarotes

Back 1

1.) Ribosomes

2.) Cell wall

3.) Pili

4.) Flagella

5.) Plasma membrane

6.) Nucleoid

7.) Cytoplasm

Front 2

How is an organelle defined?

Back 2

Structure enclosed within its own membrane inside a cell and has a particular function

(absent from prokaryotes)

Front 3

What feature of some prokaryotes could be considered organelles?

Back 3

Intracellular membranes of photosynthetic bacteria

Front 4

4 types of prokaryotes when such "organelles" can be found?

Back 4

1.) Green filamentous bacteria

2.) Proteobacteria

3.) Cyanobacteria

4.) Chlorobiaceae

Front 5

3 examples of intracellular membranes that are photosynthetic in prokaryotes?

Back 5

1.) Intracytoplasmic membrane

2.) Thylakoid membrane compartments

3.) Chlorosome compartments

Front 6

How do these intracellular compartments maximise photosynthesis?

Back 6

1.) Increasing number of photosynthetic protein complexes

2.) Maximising the size of light-exposed membrane

3.) Providing an ideal subcellular environment for photosynthesis

Front 7

What are planctomyces?

Back 7

True bacteria which contain a nuclear envelope

Front 8

How do planctomyces show true compartimentalisation?

Back 8

DNA is surrounded by a double-lipid bilayer

Front 9

What eukaryotic fiber has a prokaryotic counterpart?

What similarities do they have?

Back 9

F-actin (to prokaryotic actin-like)

Both bind ATP and polymerise

Front 10

What function does MreB serve?

Back 10

Cell shape

Front 11

What function does MamK serve?

Back 11

Organelle assembly

Front 12

What function does ParM serve?

Back 12

Plasmid segregation

Front 13

Name 2 other examples of prokaryotic actin-like filaments

Back 13

AlfA and Alp7A

Front 14

What 2 proteins are involved in bacterial morphogenesis and how are they distinguished?

Back 14

MreB and Mdl1

If MreB is removed the bacteria shows more globular, is Mdl1 is removed bacteria is long & stringy

Front 15

How do ParM filaments segregate plasmids?

Back 15

1.) ParR binds the centromeric DNA sequence (ParC)

2.) ParM polymerises and binds to ParR

3.) Filament elongation separates the plasmids

Front 16

How does ParM polymerisation segregate bacterial chromosomes?

Back 16

1.) Plasmid pairing

2.) Plasmid partitioning

3.) Cell division

4.) ParM nucleotide exchange

Front 17

What is a distant (~10-18% sequence identity) prokaryotic tubulin homologue?

Back 17

FtsZ has a similar fold to tubulin

Front 18

What makes FtsZ similar to tubulin?

Back 18

GTPase activity that controls polymerisation

The formation of protofilaments

Front 19

What is the function of FtsZ?

Back 19

Forms a ring at cell cleavage site - cell separation in prokaryotes

Front 20

Name the 4 modes of motility or prokaryotic cells

Back 20

1.) Swimming

2.) Swarming

3.) Gliding

4.) Twitching

Front 21

What types of motility are flagella-based?

Back 21

Swimming and swarming

Front 22

What are flagella essentially?

Back 22

Protein assemblies that rotate

Front 23

What drives motility of a flagella?

Back 23

Basal motor, which uses a proton gradient to rotate it

Front 24

Switch in direction is possible, true or false?

Back 24

True

Front 25

Why must prokaryotes "swim" to find food?

Back 25

They're too small to sense a nutrient gradient along their cell

Front 26

What mode does secretion-based motility follow?

Back 26

Gliding

Front 27

Describe the example of gliding in Flavobacterium spp.

Back 27

Some cells rotate over secreted adhesion proteins

Front 28

Describe the example of gliding in Myxococcus xantus

Back 28

Polysaccharide secretion might underly motility

Front 29

What mode does pili-based motility follow?

Back 29

Twitching

Front 30

Describe a pilus

Back 30

More-or-less straight and relatively rigid cell extension

Front 31

What feature means pili can retract and grow

Back 31

They are dynamic

Front 32

What is the function of pili?

Back 32

DNA exchange between cells and surface adhesion

Front 33

What can change the length of pili?

Back 33

Pilin secretion or degradation

Front 34

What can a change in pili length be used for?

Back 34

Slow gliding over surfaces

Front 35

What is twitching motility used for?

Back 35

Forming colonies

Front 36

What are pili thin polymers of?

Back 36

Pilin

Front 37

Which type of bacteria have 6 different secretion systems?

Back 37

Gram negative

Front 38

What do Type 3 and 6 Secretion Systems do?

Back 38

Inject proteins (15-30)

Front 39

What are the similarities between flagellar assembly machine and TTSS?

Back 39

25 proteins are similar

Functional homology - when deleted a similar defect occurs

Front 40

Bacteria can inject components with the cell that do what?

Back 40

Interfere with processes & supress immune defences

Front 41

How is secretion of bacterial components induced?

Back 41

Lipid recognition or abiotic clues (such as calcium, oxygen or temperature change)

Front 42

Define translocon

Back 42

Protein complex associated with the translocation of polypeptides across membranes

Front 43

What is the "needle" of a bacterium formed from and what is used for?

Back 43

Ring of proteins, 4nm wide, translocate effectors and toxins

Front 44

What can engulfed bacteria do?

Back 44

Escape the vacuole, multiply and start intracellular movement

Front 45

How can you show that bacteria use host actin to move in host cytosol?

Back 45

By mixing G-actin and bacteria in flask and seeing that the G-actin forms filamentous tails on rear of bacteria

Front 46

What do polar bacterial proteins do?

Back 46

Trigger actin polymerisation

Front 47

Describe example of polymerisation in Listeria

Back 47

ActA resembles a host protein that triggers polymerisation. The bacterium then uses the endogenous machinery to make an actin tail

Front 48

How can you show the example of ActA in Listeria?

Back 48

Point mutation of ActA affects Listeria motility so ActA seems to mediate motility

Front 49

3 life stages of a cytosolic bacterium?

Back 49

1.) Englufment

2.) Proliferation

3.) Motility