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Flashcards in lecture 1.5 Deck (51):
1

What are cytoplasmic structures within bacteria?

Cytoskeleton
Intracytoplasmic membranes
Inclusions
Ribosomes
Nucleoid and plasmids

2

What is a protoplast?

plasma membrane and everything within

3

What is cytoplasm?

material bounded by the plasma membrane

4

What is the function of the cytoskeleton?

Role in cell division, protein localization, and determination of cell shape

5

What are FtsZ's?

forms ring during septum
formation for cell division

6

What forms ring during septum formation for cell division?

FtsZ

7

What does MreB do?

rods maintain shape by positioning peptidoglycan synthesis machinery

8

How do many rods maintain shape by
positioning peptidoglycan
synthesis machinery?

MreB's

9

What maintains curve shape?

CreS

10

What does CreS do?

maintains curve shape

11

Where are Plasma membrane infoldings observed?

observed in many photosynthetic bacteria
observed in many bacteria with high respiratory activity

12

What are Anammoxosomes?

organelle – site of anaerobic ammonia oxidation

13

What organelle is the site of anaerobic ammonia oxidation?

Anammoxosome

14

What are Inclusions?

Granules of organic or inorganic material that are stockpiled by the cell for future use

15

What characterizes inclusions that have a membrane?

Single layered
membranes vary in composition
some made of proteins; others contain lipids
may be referred to as microcompartments

16

How many layers of membrane would an inclusion have?

one

17

What are storage inclsuions?

Storage of nutrients, metabolic end products, energy, building blocks

18

What are common storage inclusions?

Glycogen storage
Carbon storage
Polyphosphate-phosphate
cyanophycin granules- amino acides
gas vacuoles
magnetosomes

19

What stores phosphate?

Polyphosphate (Volutin)

20

what stores amino acids?

cyanophycin granules

21

What are microcompartments?

Not bound by membranes but compartmentalized for a specific function

22

What are carboxysomes?

CO2 fixing bacteria

23

What is a common microcompartment?

carboxysome

24

What is a gas vacuole?

inclusion
found in aquatic, photosynthetic bacteria and archaea
provide buoyancy in gas vesicles

25

What is a magnetosome?

inclusion
found in aquatic bacteria
magnetite particles for orientation in Earth’s magnetic field
cytoskeletal protein MamK (helps form magnetosome chain)

26

Desribe the nucleoid in bacteria/archaea

irregularly shaped region in bacteria and archaea
usually not membrane bound (few exceptions)
location of chromosome and associated proteins
contains the chromosome: usually 1 circular, double stranded DNA molecule
supercoiling and nucleoid proteins (HU) probably aid in folding (nucleoid proteins differ from histones)

27

decribe plasmids

Extrachromosomal DNA
usually small, closed circular DNA molecules
Exist and replicate independently of chromosome
may integrate into chromosome
Contain few genes that usually are non-essential
confer selective advantage to host
Classification based on mode of existence, spread, and function
may exist in many copies in cell
inherited stably during cell division

28

What are some of the advantages to having a plasmid?

confer selective advantage to host e. g. antibiotic resistance, N2 fixation, catabolism of various carbon sources

29

How are plasmids classified?

mode of existence, spread, function, mode of replication, and conjugation

30

where are plasmid found and in what state of DNA?

found in bacteria, archaea, some fungi
usually small, closed circular DNA molecules

31

What is curing?

the loss of a plasmid

32

What is the loss of a plasmid?

curing

33

What does conjugative mean? (in terms of plasmids)

plasmids are plasmids that have the capacity of be transferred from one bacterium to another. Not all plasmids are conjugative.

34

What are external structures?

Extend beyond the cell envelope in bacteria

35

What is the point of external structures?

Function in protection, attachment to surfaces, horizontal gene transfer, cell movement

36

What are some exampls of external structures?

pili and fimbriae
flagella

37

What are Fimbriae?

short, thin, proteinaceous appendages (up to 1,000/cell)
can mediate attachment to surfaces, motility, DNA uptake

38

What are sex pili?

required for conjugation
genes for formation found on plasmids

39

What are flagella?

Threadlike appendages extending outward from plasma membrane and cell wall that help in movement, attachement, and virulence

40

What are the functions of flagella?

motility and swarming behavior
attachment to surfaces
may be virulence factors

41

Monotrichous=

one flagellum

42

Polar flagellum=

flagellum at end of cell

43

Amphitrichous=

one flagellum at each end of cell

44

Lophotrichous=

cluster of flagella at one or both ends

45

Peritrichous=

spread over entire surface of cell

46

What are the patterns of flagella distribution?

monotrichous, polar flagellum, amphitrichous, lophortichous, peritrichous

47

What are the three parts of Flagella?

filament, hook, basal body

48

Describe the filament

extends from cell surface to the tip
hollow, rigid cylinder of flagellin protein

49

Describe the hook

links filament to basal body

50

Describe the basal body

series of rings that drive flagellar motor

51

Describe flagellar synthesis

involving many genes/gene products
new flagellin molecules transported through the hollow filament using a specific secretion system
filament subunits self-assemble with help of filament cap at tip
growth is at tip, not base