exam 2 micro chapter 5 & 6 & 7

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