prokaryotic cells
no true nucleus
eukaryotic cells
cells with a nucleus and other organelles
flagella
filamentous appendage that is a mechanism of motility
capsule
usually made of polysaccharides, allows bacteria to adhere to surfaces, and evade immune system
prokaryotic cells have what structures outside the cell wall?
flagella and capsule
what defines the cell?
the cell membrane
functions of bacterial membrane protein
support for structures signaling and communication export of toxins
peptidoglycan is only found in
bacteria
what is the cell wall subunits of bacteria?
alternating series of subunits from glycan chains part sugar and part protein
gram positive characteristics
thick cell wall multiple layers of peptidoglycan stacked less likely to lyse good target for penicillin
gram negative characteristics
thin cell wall single layer of peptidoglycan enclosed by an outer membrane usually rod shaped
lipopolysaccharide is important medically and signals the
immune system of invasion of gram neg bacteria
bacteria without a true cell wall are called
mollicutes
a capsule allows the bacteria to:
adhere to surfaces grow as biofilm makes it hard for the phagocyte to destroy it
forms a gel like region called the nucleoid, single circular double stranded DNA
chromosome
circular, double stranded DNA that are much smaller and have a few to several hundred genes
plasmid
bacterial cell division happens through:
binary fission DNA replication protein synthesis septum forms and cell divides
prokaryotic ribosomes are
70S made from 30s and 50s
eukaryotic ribosomes are
80s larger important medically because it is a target for an antibiotic
flagella have --- that move the cell
propellars
chemotaxis
bacteria sense chemicals and move accordingly they move like a drunk person nutrients attract and toxins repel
endoplasmic reticulum
synthesizes proteins not destined for cytoplasm
smooth ER does what
lipid synthesis and degradation, calcium storage
eukaryotic cells nucleus are surrounded by --- lipid bilayer membranes
two
what allows large molecules to pass?
nuclear pores
what is used to make energy in the cell?
mitochondria and chloroplasts
flagella and cilia are constructed of --
microtubules
what do both prokaryotic an eukaryotic cells have?
ribosomes
which eukaryotic cell structure is similar to and closely related to a prokaryotic cell?
mitochondria
what is a characteristic of a gram positive cell wall?
thick with several layers of peptidoglycan
END OF CH 5
START OF CH 6
what is essential for all forms of life?
carbon
phototrophic bacteria
green and purple bacteria; energy for growth is derived from sunlight; carbon is derived from carbon dioxide or organic carbon
chemotrophs
use potential energy stored in chemical compounds as an energy source
lithographs are chemotrophs that
use inorganic chemical compounds
organotrophs are chemotophs that
use organic chemical compounds
conditions that influence growth
temperature atmosphere pH water availability
psychrophiles are found in
polar regions
thermophiles are common in
hot springs
mesophiles are ---
pathogens 35 to 40 degrees celsius
humans are what degrees?
37 degrees
hyperthermophiles are usually members of
archaea
what causes food to go bad?
psychrophiles
thermophiles and hyperthermophiles are --- pathogens
not
strict anaerobes --- oxygen
HATE they die with the least bit of oxygen
strict aerobes --- oxygen
love have to have it they are organisms that only exist in oxygen
reactive oxygen species are molecules or ions with--
too few or too many electrons which damage cellular components
aerobes destroy ROS with aid of
enzymes
microaerophiles are --- but --- can be toxic
aerobic, ROS
aerotolerant anaerobes are ---
anaerobic but less susceptible to ROS usually lack catalase prefer anaerobic but can tolerate oxygen
facultative anaerobes
aerobic and anaerobic (e-coli)
most microbes are ---
neutrophiles
food can be preserved by increasing ---
acidity
halophiles survive --- percent concentration of salt
30
all microorganisms require --- for growth
water
all known halophiles are ---
archaea
--- shields microbes growing within
biofilm
biofilm may be hundreds of times more --- to disinfectants
resistant
cells communicate and coordinate actions through
gurorum sensing
quorum sensing involves:
alteration of gene expression/protein production in response in population density chemical signaling molecules signal this increase
endospores are ---
destruction resistant, dormant, and require no nutrition or energy they are extremely resistant to heat, desiccation, chemicals, UV, and boiling water
sporulation is triggered by
carbon, nitrogen limitation (nutrient deprivation)
germination of an endospore is triggered by
heat, chemical, and nutrient exposure
bacteria that rely on other organisms to make their organic compounds
heterotroph
a characteristic of bacteria that grow in a biofilm is
they are resistant to destruction
bacteria that are aerobic but cannot survive unless the concentration of oxygen is reduced below normal levels
microaerophile
thermophilic bacterium grows in what environment
50 to 70 degrees celsius
END OF CH 6
start of chapter 7
obtain energy from organic compounds
chemoorganotrophs
donates electrons to aceptor
chemotrophy
what two things do all cells have to accomplish?
synthesize new parts harvest energy to power reactions
how do cells synthesize new parts?
through cell walls, ribosomes, nucleic acids
how do we use microbes to our benefit?
biofuels food production important in labs invaluable models for study
processes that degrade compounds to release energy cells capture energy to make ATP
catabolism
biosynthetic process assemble subunits of macromolecules uses ATP to drive reactions
anabolism
enzymes are produced --- the cell
by
biological catalysts --- up conversion of substrate into a product by --- the activation energy
speed lowering
enzymes are --- specific
highly specific
an enzyme is --- up by the cell
NOT used up; it is recycled
energy in systems is --- and ----
recycled and repurposed
catabolism reactions are ---
oxidative (takes electrons off)
anabolism reactions are ----
reductive (accepts electrons)
catabolism makes -----
ATP
anabolism --- ATP
uses
substrate donates the electron
oxidation
substrate accepts electrons
reduction
3 processes to generate ATP (catabolism)
substrate level phosphorylation oxidative phosphorylation phoyophosphorlation
ATP is produced directly through glycolysis or TSA cycle
substrate level phosphorylation
use of proton motif force electron transport train (batteries)
oxidative postphorlyation
not used by human pathogens sunlight used to create a proton motive force
photophosphorlation
three central metabolic pathways:
glycolysis pentose phosphate pathway TCA cycle
splits glucose to make two pyruvates generates modest ATP, reducing power
glycolysis
primary role is production precursor metabolites NO ATP PRODUCED
pentose phosphate pathway
oxidizes pyruvates from glycolysis generates reducing power, precursor metabolites, ATP
TCA cycle
two fates for glucose molecules
can be completely oxidized to co2 for max ATP or made into precursor metabolite for biosynthesis for anabolism
"splits" sugar molecules ad energy is transferred to ATP
glycolysis
many bacteria use a ---- pathway
glycolysis
two phases of glycolysis
phase 1- consumes 2ATP phase 2- releases energy, which is transferred to 2 ATP and 2 NADH