Ch 3 Flashcards
Cell wall of prokaryotic con
Peptidoglycan provides rigidity to bacterial cell walls preventing walls from lysing
Gram - positive
Thick layer of peptidogycan that contains Teichoic acids & lipoteichoic acids
Gram- negative
This layer of peptidoglycon surrounded by an outer membrane. The outer layer of the outer membrane is lipopolysaccharicle.
Cytoplasmic membrane
phospholipid bilayer embedded with proteins. Surrounds the cytoplasm which separates it from the external environment . Also transmits information about the external environment to the inside of the cell
DNA
Carrie the genetic information of the cell
Chromosome
Carries genetic information required by cell typically a single circular double stranded DNA molecules
Plasmid
Generally carries only genetic information that may be advantageous to a cell in certain situations
Endospore
A type of dormant, so that is extraordinarily resistant to heat, desiccation, ultraviolet, light and toxic chemicals
Cytoskeleton
Pro Tien framework involved in cell division, and control of cell shape
Granules
Accommodation of high molecular weight polymers synthesized from a nutrient available in relative excess
Ribosomes
Involved in protein synthesis to subunits 30 us and 50 S join to form the 70 S ribosome
Prokaryotic cell compared to eukaryotic cell
Prokaryotic cells: no nucleus, no organelles usually have a single circular chromosome in a nucleoid region
Eukaryotic cells: have a nucleus have organelles have a nucleus surrounded by a complex nuclear membrane, and contain multiple chromosomes, tend to be larger
Both eukaryotic and prokaryotic cells have
The cell membrane, DNA ribosomes
Prokaryotic cells, ( bacteria, archaea )
No nucleus, DNA is concentrated in a nucleoid no organelles
bacteria: peptidoglycan cell walls
Archaea: pseudopeptidoglycan cell walls
Divides by binary fission
Eukaryotic
Has a nucleus that houses DNA
Has organelles
Polysaccharide cell walls when present like in plant cells
Humans do not have a cell wall
Divide by mitosis
Prokaryotic cell components
Flagella
Pili
Capsule
Cell wall
Plasma membrane
Cytoplasm
Nucleoid where the DNA is concentrated
Ribosomes
Endospores
Streptococcus pyogenes
Coccus shaped
Gram-positive bacteria causes disease such as strep throat
E.Coli
Rod shaped, gram-negative, bacillus bacteria normally found in the intestines of healthy humans. Most strains are harmless. Some strains can cause illness.
H.Pylori
Spiral bacterium gram-negative common cause of stomach ulcers
Flagella
Flagella involved in bacteria motility
Spin like propellers to move cells
Long proteins structure
Some important and diseases
Number an arrangement help with characterization of bacteria
Polar flagellum: single flagellum at one end of cell
some bacteria have tuft at one or both ends
Flagella in bacteria
Three parts
Filament, flagellin, protein
Hook
Basal body
Pili
Shorter than flagella
Made of proteins
Common pili allows bacteria cells to attach to surfaces via twitching gliding
Sex pilus
used to join bacteria for DNA transfer and bacterial conjugation
Plasmids can be transferred to another bacteria this way
Mechanism involved in spreading antibiotic resistance
Chemotaxis
Bacteria, sense, chemicals, and move accordingly
Nutrients me attract toxins may repel
Movement a series of runs and tumbles
Other responses observed
Aerotaxis
Oxygen
Thermotaxes
Temperature
Phototaxis
Light
Capsules and slime layers
Gel like layer outside the wall that protects or allows attachment to surfaces
Capsule distinct gelatinous
Slime layer defuse, irregular
Most composed of glycocalyx sugar shell, although some are polypeptides
Allow bacteria to adhere to surfaces once attached cells can grow as biofilm
Bio film problems in medicine
Polymer in case community of microbes
Some capsules allow bacteria to invade host immune system
Dental plaques are common bile from the form in teeth
Cell wall prevents cell lysis
Strong and rigid structure prevents cell lysis
Penicillin and gram staining
Gram-positive are generally more susceptible
Gram-negative are generally less susceptible
Cell wall is made from peptidoglycan
Alternating series of subunits form, glycan sugar, chains
Interconnected like in chains, form a large sheet
A tetra peptide chain string of four amino acid link glycan chains
Glycan chains
N acetylmuramic acid
B acetylglucosamine
What type of peptidoglycan layer do gram-positive cell walls have
Thick layer and contain techoic acid
Gram-negative cell wall
Thin peptidoglycan layer
Has an outer membrane
Embedded with proteins
Porins lipoprotein lipopolysaccharides
Lipopolysaccharide
Important, medically signals immune system of invasion by Graham negative bacteria
Also called an Endo toxin
Stimulate immune system
Gram stain
Gram-positive, bacteria, stain, purple
Graham negative bacteria stain, pink, or red
Purpose of gram staining
Gram staining can provide an early indication of the potential bacteria, causing a patient’s infection through visualization
Antibacterial substances that target peptidoglycan
Peptidoglycan makes good target since it’s unique to bacteria and can weaken points were unable to prevent cell lysis
Penicillin interferes with peptidoglycan synthesis because it prevents cross-linking of adjacent glycan chains
Lysozyme break bonds, linking alternating subunits of like in chains
Where is Lysozyme found
It’s found in tears and saliva or other bodily fluids, and it destroys the structural integrity of peptidoglycan molecules
Bacteria that lack a cell wall
Mycoplasma have extremely variable shape
Penicillin and lysozyme do not affect
Cytoplasmic membrane contain steroids, increase strength
Walking pneumonia is caused by mycoplasma bacteria
The cytoplasmic membrane
The cytoplasmic membrane defines boundary of cell and helps prevent lysis and protects the cell
Phospholipid bilayer of embedded with proteins
Hydrophobic fatty acid tails face in hydrophilic heads face out membrane is semi permeable
Proteins serve numerous functions, selective gates centers of environmental conditions,
Fluid mosaic model
Proteins drift about in lipid bilayer
Functions of the cytoplasmic membrane
Protect cells and defines a boundary of the cell
Semi permeable membrane
Transports let’s nutrients in and waste out
Senses the environment
ATP energy production
Permeability of lipid bilayer
Cytoplasmic membrane a selectively permeable
O2 CO2 N2 are small hydrophobic molecules, and water pass freely
Some cells facilitate water passage with aquaPorins
Others must move the membrane via transport system, ATP
Passive transport
No energy needed
substances move from high concentration to low concentration
Movement down gradient no ATP required
Facilitated diffusion is a form of passive transport
Active transport
Requires energy
Substances move from low concentration to high concentration. Movement is a against the concentration gradient.
Via proton motive, force, and the use of ATP
Passive transports
Simple, diffusion movement of small soluble molecules from high to low concentration speed depends on the
Facilitated diffusion, involves a membrane transport proteins
Osmosis, passive transport of water, cost us a membrane, diffusion of water across selectively permeable membrane due to an unequal concentration from an area of high water to an area of lower water. Concentration and water can move via simple diffusion of facilitated diffusion.
Osmotic pressure
The pressure exerted on sells by the water concentration in their environment
Water by nature moves where there are more solutes
If there is more salt inside the south and outside, water moves into the cell vice versa
Isotonic solution
Solute concentration is the same inside and outside of the cell
Hypotonic solution
Solution has less salute then cell
Hypertonic solution
Solution has more solute then cell
Electron transport chain
Embedded in the cytoplasmic membrane of prokaryotes
Plays a crucial role in converting energy into to ATP
In eukaryotic cells, etc, occurs in the mitochondrial membrane
Etc creates an electrochemical gradient across the membrane in the membrane is called proton motive force, which is harvested to drive cellular processes, including ATP synthesis, and some forms of transport
DNA
Singular circular piece of DNA
Packed tightly via binding proteins and super coiling
Genetic material is essential for life
Found in the nucleotide region of the cytoplasm
Plasmids
Small circular, super coiled, DNA
May or may not be present in a cell
A bacteria cell has zero placements, one or many
Not essential for life, but provide advantage
Usually much smaller few to a hundred several genes
May share with other bacteria, antibiotic resistance can spread this way
Ribosomes
Found in cells cytoplasm
Made up of rRNA and proteins
Help make proteins in the cell
Relative size expressed as S Svedberg unit
Prokaryotic ribosomes are 70 S made from 30 S and 50 S
Eukaryotic ribosomes are 80S made from 40 S and 60 S
Internal components of prokaryotic cells
Cytoskeleton which provides framework
Gas vesicles provides buoyancy or the tendency to float in water
Storage granules accommodations of polymers synthesized from nutrient available the next test
Endospores you need type of dormant, so may remain dormant for 100 years or longer. Endospores are extremely resistant to heat found virtually anywhere.
Endospores
Sporulation endosperm formulation triggered by carbon, nitrogen, limitation or starvation conditions and is an eight hour process and is formed and released by the mother cell
Germination vegetative cell grows one hour to two hours is how big is the Grogan and is triggered by heat chemical exposure
Archaea similar get different from bacteria
Bacteria and arche has general structure of cytoplasmic membranes with different lipid compositions
Lipid tales of Achaea are not fatty acids and are connected differently to glycerol
Archaea cell membrane is composed with either linkages with branch isoprene chains
Bacteria cell membrane is composed with Ather linkages with unbranched fatty acid
Archaea versus bacteria
Archaea cells lack peptidoglycan
Some contain a structurally, similar substance called pseudo peptidoglycan
The genomes of our care or longer and more complex, and those are bacteria
