Unit 2 - Cell Organelles, Plasma Membrane, Transport Flashcards
Prokaryote characteristics
- no membrane bound nucleus
- circular DNA
- simple
- ribosomes floating in cytoplasm
Eukarytoe characteristic
- membrane bound nucleus, structures
- linear DNA
- multicellular: mitochondria/chloroplast, golgi
- bound ribosomes
Compartmentalization
local environments for different functions (lysosome has a different pH)
Endosymbiosis
- folding of plasma membrane
- engulfing of aerobic prokaryote
- autotrophs diverge from heterotrophs
- autotroph engulfs photosynthetic prokaryote
- ancestral eukaryotes develop
Cell Wall (prokaryote, plant)
plant: cellulose
fungi: chitin
prokaryote: peptidoglycan
help with shape/structure and also protection
Plasma membrane (all three)
phospholipid bilayer
help with H2O regulation/pressure, help transport things across the membrane
Ribosome (all three)
protein synthesis!
prokaryotes: free in cytosol/cytoplasm
eukaryotes: bound (rough ER)
Smooth ER (eukaryotes)
make lipids, detoxification
Rough ER (eukaryotes)
ribosomes bound, form protein
Golgi (eukaryotes)
modifies, packs, and sorts proteins/materials
cis (close to RER) and trans side (where proteins bud off)
Mitochondria (eukaryotes)
double membrane with cristae (inner membrane)
cellular respiration
more mitochondria = more metabolism
more surface area of inner membrane = more rate of exchange, more efficient kreb cycle
Lysosome (eukaryotes)
digestion, pH: 5 (acidic), autophagy (recycle cell matter), hydrolyze
Nucleus (eukaryotes)
chromosomes, double membrane
Peroxisome (eukaryotes)
enzyme that converts peroxide into water
Chloroplast (plant only)
photosynthesis
thylakoid (singular disk) and grana (stack of disks): light dependent
stroma (fluid): calvin/dark cycle
Vacuole (eukaryotes)
food vacuole: phagocytosis
contractile: maintaining water level
central (plants): turgor pressure
Cytoskeleton (eukaryotes)
structural support:
1. microtubules (tubulin): movement of cells, support
2. microfilaments (actin): structure support, shape/tension
3. intermediate filaments (fibrous protein): movement of materials, shape, anchor, cushion
Centrioles (animal only)
function during reproduction with spindle fibers
Endomembrane system
- RNA attaches to the ribosome, turns primary structure to polypeptide (mRNA to polypeptide) in the lumen of the RER
- protein leaves RER in a vesicle and goes into golgi cis side
- modified and packaged in golgi and leaves in vesicle from trans side (budding off)
- vesicle is transported to other parts of cell or out of membrane
Cell size
increased surface area and colume = increased rate of material exchange
Osmoregularity
regulate solute and concentrations to maintain water balance, high to low water potential, low to high solute
Hypotonic
hypo: low water inside, high solute
cell gains H2O
plants use this for turgor pressure (vacuole), turgid
Hypertonic
hyper: over water inside, low solute
cell loses H2O
plasmolysis
Isotonic
dissolved, balanced
Phospholipid head
philic, polar
Phospholipid tail
phobic, nonpolar
What can pass through a phospholipid bilayer without anything?
small, nonpolar
N2, O2, CO2, hormones, lipids
Integral protein
embedded, amphipathic (part sticking out is philic and part within the membrane is phobic)
Peripheral protein
loosely bonded on the surface, philic
Glycolipid/protein
cell-to-cell recognition
Carrier protein
conformational change
glucose, nucleoside, animo acids
ions, large, polar
Channel protein
tunnel is philic, outside touching membrane is phobic
aquaporins (H2O)
ions, large, polar
Cholesterol
temperature buffer, maintains fluidity
inc. temp. = dec. movement
dec. temp. = inc. movement
Active transport
requires ATP, against concentration gradient (low > high)
Sodium Potassium Pump
2 Na+ are pumped out, 3 K+ are pumped in against their concentration gradients through carrier proteins that change when phosphate from ATP is attached
creates an electrochemical gradient since more positive on the inside due to net +1 from the K+
Cotransport
Lots of H+ on the outside and O wants to move in against it’s concentration gradient
due to H+ electrochemical gradient, it will flow back in and bring an oxygen with it
Symporter
cotransport where both things move in with the same direction
Antiporter
cotransport where the action of one moving in/out will move the other one in the opposite way
Exocytosis
lysosome digests material and sends it in a vesicle to fuse with the membrane and thrown out (all with the sue of ATP)
Phagocytosis
food is engulfed fully by the membrane (food vacuole) which will then fuse with the lysosome
Pinocytosis
small molecules engulfed by membrane (protein coated vesicle)
Receptor-Mediated
receptors detect specific substances which are engulfed by the membrane and transported
Osmosis
diffusion of high H2O to low H2O (or low solute to high solute)
Passive transport
with the concentration/electrochemical gradient
Diffusion
high to low, selectively permeable membrane (allows for different rates of diffusion for different molecules)
