Lecture 13 - Inclusions

Question 1

Reserve deposits located within the cytoplasm

-kinds of specialized devices adapted to diverse metabolic strategies and environments

Answer 1

Inclusions

Question 2

These inclusions are specialized structures used for:

Answer 2

• energy reserves
• carbon reserves
• functions such as motility

Question 3

Gram-negative prokaryotes can oxidize reduced sulfur compounds such as hydrogen sulfide…these organisms are?

The oxidation of sulfide is linked to the need for _______ to drive either ________ or _________.

Answer 3

sulfur bacteria

electrons, energy metabolism or carbon fixation

Question 4

Elemental sulfur from the oxidation of sulfide may accumulate in the cell in microscopically visible ________ .

Answer 4

sulfur granules

as reduced sulfur sources become limiting, the sulfur in the granules is oxidized to sulfate and the granules will disappear

Question 5

Some bacteria orient themselves within a magnetic field because they contain…

Answer 5

magnetosomes (Fe3O4)

Question 6

Magnetosomes allow bacteria to?
Bacteria that produce magnetosomes exhibit?
Magnetic material enclosed in?
Useful for water treatment because?

Answer 6

• orient themselves in a magnetic field
• magnetotaxis (ex. swim downward to low oxygen levels) bacteria a combine magnetosomes and oxygen-sensing proteins to move to an optimal environment
• a membranous infolding of the cytoplasmic membrane
• accumulate high concentrations of toxic metals from water

Question 7

Many microbes accumulate inorganic ______ in the form of ________ also called ________.

What can these granules be used for?

Answer 7

phosphate, polyphosphate, Volutin

-granules can be degraded and used as sources of phosphate for nucleic acid, and phospholipid biosynthesis and in some organisms can be used directly to make ATP.

Phosphate is often a limiting nutrient, so if microbe stumbles upon a large supply it is advantageous to be able to store it.

Question 8

Inclusion that allows for buoyancy in aquatic prokaryotic cells

ex. cyanobacteria (float toward light)

Answer 8

gas vesicles - allows cells to position themselves in a water column

gas vesicles are conical shaped structures made of protein; they are hollow yet rigid - permeable to gases and not water and solutes

Question 9

Inclusion used for extreme survival employed by gram _______ bacteria.

Answer 9

endospore, employed by gram positive bacteria

Question 10

Endospore production is initiated in response to what? And allows the bacterium to produce what? And makes it resistant to what? Stability comes from?

Answer 10

• nutrient deprivation
• produce a dormant and highly resistant cell to preserve cell’s genetic material in times of extreme stress
• heat, UV, chemical stress, and dehydration
• stability comes from spore specific chemicals (dipicolinic acid) and proteins protecting DNA

Question 11

The process of endospore formation within a vegetative cell (which is an actively growing cell) takes several hours and is known as __________ .

Answer 11

sporulation

Question 12

Endospores can be dormant for thousands of years and may return to its vegetative state by a specialized process called __________ when conditions are improved for the cell.

Answer 12

germination

Question 13

Endospores are a problem in food and medicine because?

Answer 13

They are not readily killed by many antimicrobial treatments. Botulism (consumption of food with endospores).