Structure - Bacterial Alternate Structures

Question 1

Cell Inclusions

Answer 1

Cellular energy reserves and carbon reservoirs.

Question 2

Why do bacteria prefer carbon stored in insoluble form?

Answer 2

Reduction of osmotic stress due to reduced cytoplasmic substance dissolution

Question 3

General structure of poly-beta-hydroxybutyric acid/

Answer 3

Hydroxybutyrate polymerised via Ester linkages

Question 4

What is the variable length of hydroxybutyrate?

Answer 4

C3-C18.

Question 5

What is hydroxybutyrate generally referred to as?

Answer 5

poly-beta-hydroxyalkanoate.

Question 6

When are poly-beta-hydroxyalkanoate synthesised?

Answer 6

When cell is saturated with carbon, to be used as an energy source.

Question 7

What can cell inclusions store?

Answer 7

Carbon, sulfur, phosphate etc.

Question 8

What form do Cell Inclusions store phosphate in?

Answer 8

Polyphosphate form.

Question 9

Why are phoshpate cell inclusions important?

Answer 9

Phosphate is often a limiting nutrient

Question 10

Magnetosomes

Answer 10

Allow certain magnetotactic bacterial cells to move towards the magnetic field of earth.

Question 11

What is the main component of a magnetosome?

Answer 11

Fe3O4

Question 12

Why is Fe3O4 important?

Answer 12

Guides cells twoards earths magnetic field to lower O2 levles.

Question 13

Gas Vesicles

Answer 13

Increase cell buoyancy by decreasing cell density.

Question 14

What is an example of where gas vesicles are used?

Answer 14

Planktonic organisms floating within nutrient rich locations.

Question 15

What does the structure of the gas vesicle allow for its function?

Answer 15

Gas difusion but water impermeability.

Question 16

What proteins make up the vesicle structre?

Answer 16

GvpA forms watertight vesicle shells that are small, hydrophobic and rigid whilst GvpC links these GvpA together

Question 17

What is the mechanism of Gas Vescile buoyancy?

Answer 17

Contain 1/10 cell density, inflating decraasing overall density, increasing buoyancy.

Question 18

In what process are endospores produced.

Answer 18

During sporulation

Question 19

What are some chemical characterisitcs of endospores?

Answer 19

Resistinat to heat, harsh chemical and radiation.

Question 20

What is the function of endospores?

Answer 20

Allow an organisms to endure unfavourable conditiosn

Question 21

What organisms are endospores usually foudn in?

Answer 21

Bacillus or soil bacteria.

Question 22

What happends to VG during sporulation?

Answer 22

It enters a dormancy like stage without growth but high resistance.

Question 23

What are the three steps of endospore invigoration after formation?

Answer 23

Activation, Germination, Outgrowth.

Question 24

What happens in endospore activation?

Answer 24

Heat endospores elevates temeprautres.

Question 25

What happens in endospore Germnination?

Answer 25

Nutrient supplication which decreases resistance due to increaseing refractility.

Question 26

What happens in endospore Outgrowth?

Answer 26

Water uptake, DNA/RNA/PROTEIN synthesis, cell emergence from broken endospores.

Question 27

How are endospores observed in culutre?

Answer 27

Impermeable to dyes, seen as unstained regions, special stains used.

Question 28

What are the four layers distinct in endospores from VG?

Answer 28

Exosporium, spore, cortex then core.

Question 29

How much of endospore dry weight is dipicolinic acid?

Answer 29

10%

Question 30

What does Dipicolinic acid do?

Answer 30

Binds free water to dehydrate the cell and stabilses DNA against heat denaturation, inserting between bases.

Question 31

How does the endospore core differe from VG cytoplasm?

Answer 31

Less water and small acid soluble spore protiens.

Question 32

What is the important of less water in endospore core?

Answer 32

Increases gel-like consistency allowing heat resistance of their macromolecules.

Question 33

What are the functions of SASSP?

Answer 33

Protecting DNA from UV damage, compacting it from B form to A form and as carbon source in outgrowht.

Question 34

How many proteins are required for sporulation?

Answer 34

over 200 requiring differential protein synthesis.

Question 35

What happens genetically in sporulation?

Answer 35

Activation of endospore specific genes and inactivation of VG genes.

Question 36

What is the first stage in sporulation?

Answer 36

Asymmetric cell divions forming forespore and mother cell

Question 37

What is the second stage of sporulaiton?

Answer 37

TF control each gene expressive fates.

Question 38

When does sporulation occur?

Answer 38

After DNA replication completes one round so chromosome copies are available.

Question 39

What happens when division occurs in sporulation?

Answer 39

Forespore is engulfed by mother cell

Question 40

How does forespore engulfing occur?

Answer 40

Proteins facilitate membrane migration around forespore.