Flashcards in lecture 1.5 Deck (51):
What are cytoplasmic structures within bacteria?
Nucleoid and plasmids
What is a protoplast?
plasma membrane and everything within
What is cytoplasm?
material bounded by the plasma membrane
What is the function of the cytoskeleton?
Role in cell division, protein localization, and determination of cell shape
What are FtsZ's?
forms ring during septum
formation for cell division
What forms ring during septum formation for cell division?
What does MreB do?
rods maintain shape by positioning peptidoglycan synthesis machinery
How do many rods maintain shape by
What maintains curve shape?
What does CreS do?
maintains curve shape
Where are Plasma membrane infoldings observed?
observed in many photosynthetic bacteria
observed in many bacteria with high respiratory activity
What are Anammoxosomes?
organelle – site of anaerobic ammonia oxidation
What organelle is the site of anaerobic ammonia oxidation?
What are Inclusions?
Granules of organic or inorganic material that are stockpiled by the cell for future use
What characterizes inclusions that have a membrane?
membranes vary in composition
some made of proteins; others contain lipids
may be referred to as microcompartments
How many layers of membrane would an inclusion have?
What are storage inclsuions?
Storage of nutrients, metabolic end products, energy, building blocks
What are common storage inclusions?
cyanophycin granules- amino acides
What stores phosphate?
what stores amino acids?
What are microcompartments?
Not bound by membranes but compartmentalized for a specific function
What are carboxysomes?
CO2 fixing bacteria
What is a common microcompartment?
What is a gas vacuole?
found in aquatic, photosynthetic bacteria and archaea
provide buoyancy in gas vesicles
What is a magnetosome?
found in aquatic bacteria
magnetite particles for orientation in Earth’s magnetic field
cytoskeletal protein MamK (helps form magnetosome chain)
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)
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
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
How are plasmids classified?
mode of existence, spread, function, mode of replication, and conjugation
where are plasmid found and in what state of DNA?
found in bacteria, archaea, some fungi
usually small, closed circular DNA molecules
What is curing?
the loss of a plasmid
What is the loss of a plasmid?
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.
What are external structures?
Extend beyond the cell envelope in bacteria
What is the point of external structures?
Function in protection, attachment to surfaces, horizontal gene transfer, cell movement
What are some exampls of external structures?
pili and fimbriae
What are Fimbriae?
short, thin, proteinaceous appendages (up to 1,000/cell)
can mediate attachment to surfaces, motility, DNA uptake
What are sex pili?
required for conjugation
genes for formation found on plasmids
What are flagella?
Threadlike appendages extending outward from plasma membrane and cell wall that help in movement, attachement, and virulence
What are the functions of flagella?
motility and swarming behavior
attachment to surfaces
may be virulence factors
flagellum at end of cell
one flagellum at each end of cell
cluster of flagella at one or both ends
spread over entire surface of cell
What are the patterns of flagella distribution?
monotrichous, polar flagellum, amphitrichous, lophortichous, peritrichous
What are the three parts of Flagella?
filament, hook, basal body
Describe the filament
extends from cell surface to the tip
hollow, rigid cylinder of flagellin protein
Describe the hook
links filament to basal body
Describe the basal body
series of rings that drive flagellar motor