chapter 3 Flashcards
exam 1
spontaneous generation
life can arise from non living things
biogenesis
living organisms can only arise from preexisting life
Francesco redi
experiment with containers of meat covered/uncovered and seeing if maggots will form
John Needham
experiment w broth but had microbial growth bc he didn’t heat up broth to kill preexisting microbes
Germ Theory of disease
microorganisms can invade macroorganisms and cause disease
Lazzaro Spallanzani
same broth experiment but didn’t have microbial growth
Louis Pasteur
broth experiment that disproved sponteneous generation w swan neck flasks
Kochs Postualtes
- A specific causative agent must be found in every case
- infectious agent must be isolated on pure culture
- infect a heathy person w agent and must present same symptoms and disease
- infectious agents must be recovered from an inoculated individual
Immunization prevents disease
18th century incidence of smallpox decreased by deliberately inoculating children with material from smallpox pustules
who intrdocued the prsvtice of small pox inoculation
Lady Mary Wortley Montagu
Edward Jenner
noticed m milkmaids never contracted smallpox bc they had cowpox
developed the first successful immunization against smallpox
Ignaz Semmelweis
introduced the idea of handwashing between moving patients to prevent diseases from one patient to the next
decreased infection rate drastically
savior of mothers
Joseph Lister
used carbolic acid to sterilize dressings and developed sprays in the surgical room
antiseptic surgery
aseptic
no microorganisms
monoseptic
one microorganism
septic
mutliple microorganisms
antibiotic
internal medication that could be used to kill microbes but not the patient
alexander Fleming
founded antibiotics
penicillin - Penicillium chrysogenum
endosymbiotic theory
explains the origin of certain organelles in eukaryotic cells, specifically mitochondria and chloroplasts. According to this theory, these organelles were once free-living prokaryotic organisms (like bacteria) that formed a symbiotic relationship with a host cell.
evidence that mitochondria and bacteria are vestigial bacteria
same size as bacteria
double mem structure
own DNA
DNA is arranged in a circular formation
70s ribosome
divide independently of host eukaryotic cell
unique characteristics of prokaryotes
small size
small genome
circular chromosomes
no intracellular endosymbiotic organelles
peptidoglycan
chromosomes replicate and segregate during cell growth
glycan
sugar polymer—a chain of sugars (monosaccharides) linked together by glycosidic bonds.
glycoprotein
help provide structural support to cell
glycolipid
cell stability/cell recognition
transmembrane protein
span cell membrane
peripheral protein
in 1 portion of the cell membrane
phospholipid biklayer
makes up the cell membrane and allows some permeability
hydrophilic heads
hydrophobic tails
simple diffusion
passive transport
move from high to low concentration (moving down gradient)
small lipid-soluble molecules
facilitated diffusion
passive transport
move from high to low concentration (moving down gradient)
larger insoluble molecules that need a transport protein to pass
Active transport
Needs ATP to move molecules against their gradient
from low to high concentration
Antiporter
moves 2 different molecules in opposite directions across the membrane
doesn’t directly use ATP but uses energy from moving one molecule down its gradient to power the movement of the molecule that is moving against its gradient
symporter
active transport
both molecules move in same direction across the membrane
doesn’t directly use ATP but uses energy from a molecule moving down its gradient to power the movement of a molecule against its gradient
ABC systems
ATP binding cassette
specific regions on the cell membrane have areas for ATP to bind and use its energy
use ATP to move molecules against membrane
molecule to be transported will bind to a specific protein on the cell
group translocation
active transport
a molecule is transported into the cell and is chemically alerted
molecules shape is changed so it is prevented from leaving the cell easily
capsule in gram positive bacteria
allows for adherence to surfaces for bacteria
made up of polysaccharides
prevents bacteria from being recognized by hosts immune system
prevent dessication
periplasmic space
space between the inner membrane and peptidoglycan layer
structure of peptidoglycan
consists of alternating chains of NAG and NAM that are connected via glycosidic bonds
have peptide chain that connects the NAM molecules of adjacent glycan chains
what does gram + peptidoglycan have
has a peptide cross bridge, which attaches the peptide chains to adjacent glycan strands
gram +
gram -
mycobacterium
teichoic acid
LPS
mycolic acid
Lipopolysaccharide (LPS)
endotoxin
gram -
3 parts
- lipid a
- core polysaccharide
- o antigen
Lipid A is responsible for toxic properties
found on the outer membrane
teichoic acid and lipoteichoic acid
teichoic acid is attached to the peptidoglycan
and lipoteichoic acid is attached to the phospholipid bilayer
GRAM POSITIVE
Atypical cell walls
Mycoplasmas
- lack cell walls
- sterols in the plasma membrane
Archaea
- wall-less or walls of pseudomurein
when talking abt iso/hypo/hyper tonic
we are talking abt the conditions of the external environment (ex. the solution the cell is in) of the cell
isotonic
same solute concentration as another solution
no net movement of water
hypotonic
the external environment has a lower solute concentration than the cell
water will enter the cell causing it to lyse
hypertonic
the external environment has a higher solute concentration than the cell
water will leave the cell causing it to crenate
tonicity
the degree to which a cell can withstand changes in osmotic pressure
cells that have a cell wall can withstand changes better
bacterial cell division
replicate quickly bc all organelles are in one place
not all genes are expressed at the same time - affected by DNA binding protein
ribosomes
where protein synthesis takes place
two subunits in prokaryotes
The 30S and 50S come together to make 70-S
30S has smaller 16s subunit and 50S had 23s and 5 s subunits
endospores
bacterial species can shoot out spores to preserve their DNA when the environment is unfavorable
sporulation
vegetative cells turn into endospores
flagella
structures used by the cell to move in aqueous environments
act like propellers
monotrichous
one flagella on one end
amphitrichous
one flagella on each end
lophotrichous
multiple flagella from one end
peritrichouse
flagella coming from everywhere
counterclockwise movement
bundle the flagella all together and allow bacteria to run forward
clockwise movement
flagella goes in all different directions , stop forward movement and allows bacteria to tumble backward
chemotaxis
the movement of an organism or cell in response to a chemical stimulus. Specifically, it’s the process by which cells or bacteria move toward or away from certain chemicals in their environment
what is in the plasma membrane of eukaryotes
phospholipid bilayer
transmembrane proteins
peripheral proteins
integral proteins
sterols
glycocalyx carns
glycocalyx in eukaryotes
carbs that come off the plasma membrane of animal cells that are bonded to proteins/lipids
ribosomes in eukaroytes
protein synthesis
80s ribosome
with a 40s (18s) and 60s subunit
BUT 70S IN MITOCHONDRIA/CHLOROPLASTS
Nucleus
contains chromsomes
ER
transport network
golgi complex
membrane formation and secretion
lysosome
digestive enzyme
vacuole
brings food into cells and provides support
mitochondria
cellular respiration
chloroplasts
photosynthesis
peroxisome
oxidation of fatty acids, destroy H2O2
centrosome
consists of protein fibers and centrioles
flagella arrangement in eukaryotes
2 central microtubules
and 9 doublet microtubules that go around the 2 in a circle
pseudopoda
false feet , projections of cell membrane when moving
porins
found in gram-negative bacteria
form channels through the OM and allow small molecules to enter the cell
