Chapter 3- Prokaryotic Cell Flashcards
Prokaryotic cytoplasmic/ cell membrane
phospholipid bilayer embedded w/ proteins that serve many functions; selectively permeable & the few compounds that pass do via simple diffusion
Converting the energy of food/sunlight into ATP takes place where in a prokaryotic cell?
Cell Membrane- play important role in energy transformation
a form of passive transport that does not require energy and moves substance down a concentration gradient (high to low concentrations)
Facilitated Diffusion
moves substances against concentration gradient and requires ATP/energy (from low to high concentration/ upstream) mainly used by prokaryotes
Active Transport
strong, mesh like macromolecule that provides strength and rigidity to cell wall and only found in bacteria
Peptidoglycan
These prokaryotic cell walls contain a layer of peptidoglycan and their structural arrangement distinguishes two main groups of bacteria
Gram Negative (thin) Gram Postive (Thick)
Peptidoglycan is exclusive to
Bacteria only
Peptidoglycan contains
alternating subunits of NAM and NAG that are closely related to glucose
Gram Positive Cell Wall (Positively THICK WIDDDIT)
thick layer of peptidoglycan w/ many interconnected glycan chains; within peptidoglycan are TEICHOIC ACIDS that project out of the peptidoglycan
Teichoic Acids role in Gram Positive Cells
negatively charged chains where various sugars attach
Gram Negative Cell Wall (To be too THIN is Negative)
thin layer of peptidoglycan where periplasm fills space between peptidoglycan and outer membrane
Outer Membrane of Gram NEGATIVE cell
made up of Lipopolysaccharides (LPS) which is an endotoxin bc it can alert the body if it has been exposed to gram negative bacteria (significant amount of LPS can be deadly)
responsible for gram staining after trying to identify cause of pneumonia and bacterias stained unequally
Dr. Christian Gram
Purpose of gram staining
to identify two major groups of bacteria according to cell wall struture/chemistry
Prokaryotic cells (bacteria/archaea)
small size, allows rapid growth, rapid uptake of nutrients, prone to predators & competitors
Eukarya (Protozoa, Fungi, Algae)
have nucleus, large, have membrane bound organelles
How do most prokaryotes divide?
By Binary Fission, and usually stick together following division
Example of bacteria that lacks a cell wall bc it contains sterols (only SOME lack cell wall)
Mycoplasma; not affected by penicillin or lysozymes
Cell envelope of prokaryotes incluse
plasma membrane, cell wall and capsule (if present)
Within cell envelope, there is cytoplasm, which houses
the nucleoid
Nucleoid
Gel like region that contains the cell’s DNA/ chromosomes (not membrane bound)
Prokaryotic cells contain
Cell envelope (tree parts), Cytoplasm, Nucleoid, Other appendages that help with motility and ability to attach to other
Cytoplasmic Membrane Structure
Phospholipid bilayer w/ Hydrophilic Head Hydrophobic tail
What can pass freely through plasma membrane of a prokaryote cell?
Small hydrophobic substances, O2 , CO2 , N2, water (w/ aquaporins);
Movement from HIGH to LOW concentrations
Simple diffusion
Net movement of water through semi permeable membrane
Osmosis
Water flows from ________ to ________ solution
hypotonic ; hypertonic
No net water movement occurs in this solution
Isotonic
HYPO
less
HYPER
More
TONIC
solute
Water moves towards _______ solution
Hypertonic (high solute)
A cell will shrink in a ________ solution (get small when the crowd is hype)
Hypertonic
A cell will swell in a __________ solution
hypotonic
Cell Wall made up of
Peptidoglycan
Lipopolysaccharides (an endotoxin)
found in Gram Negative Cell walls; help the bacteria survive in guts of animals; can detect presence of Gram Negative bacteria in humans
Interference with peptidoglycan
can weaken cell wall & cause cell to burts
What (substances) interferes with peptidoglycan synthesis?
Penicillin; Lysozymes as they break bonds linking glycan chains; more effective on Gram Positive Cell walls as they have thick layer of peptidoglycan
Acid fast bacterias
resist decolorization by acids in staining procedures due to wax like nature of mycolic acid cell wall
Cell walls of archaea are various and do not contain
peptidoglycan
gel like layers outside cell wall that protects or allows attachments
capsules (gel like) / slime layers (irregular/diffused)
Capsules and slime layers can allow cells to grow _______ and help bacteria do what?
Biofilm; evade host’s immune system
This glycocaly TIGHTLY bound to cell wall helps cells act as pathogens and protects cells against phagocytosis by host
Capsule
This glycocalyx is LOOSELY attached to cell wall and important component of biofilms (slimes mad loose)
Slime Layer
Prokaryotic Appendages that provide motility & attachments
Fimbriae, Pili, Flagela
Flagella involved in ______; and allows cell to
MOTILITY; move on its own
Flagella Types (peri, mono, amphi, lopho)
Peritrichous (all over cell) ; Polar (mono- at one end) (amphi (at both ends); lopho (tuft of hair at ONE end)
Motility of bacterium to move toward favorable and away from unfavorable conditions is a process called (thumbs up to hail this)
Taxis (Multiple types)
When bacterias sense chemicals and move accordingly
CHEMOtaxis
Used for attachment rather than movement; allows cells to adhere to body surfaces; shorter, can occur in bunch
fimbriae
used for motility and transfer of DNA; longer and fewer; gliding movements; makes power strokes; DNA transfer (conjugation)
Pili
chromosomes form this gel like structure; has single circular double stranded DNA
nucleoid
small, structures that do not encode DNA, and antibiotic resistance can spread this way
Plasmids
dormant, extremely resistant type of cell produced by bacteria found everywhere. Can germinates to become vegetative & multiply
Endospores
