Cellular Bio Flashcards
cell membranes composition
phospholipids and proteins
phospholipid bilayer
lipid soluble substances ability to cross cell membranse
can cross cell membranes with NO TRANSPORTER and dissolve in hydrophobic lipid bilayer
O2, CO2, steroids, etc
water soluble substances ability to cross cell membranse
cannot dissolve in lipid of membrane but may cross through water filled channels/pores or be transported by carriers
Na, Cl, glucose, H2O, etc
where are integral proteins located
span the entire cell membrane; anchored through hydrophobic interactions with phospholipid bilayer
where are peripheral proteins located
on either intracellular or extracellular side of cell membrane
ex of integral proteins
ion channels, transport proteins
ex of peripheral proteins
hormone receptors
types of transport pathways
diffusion (high to low conc; passive)
- simple
- facilitated (carriers)
active transport (pumps)
what is the Na out/K in ratio for the Na-K ATPase transporter
3Na+ out, 2 K+ in
what are the types of intercellualr connections
tight junctions (zonula occludens) gap junctions
function of tight junctions vs gap junctions
tight junctions = intercellular pathway for solutes
gap = permit intercellular communication
for which of the cell membrane transport pathways (passive/diffusion, facilitated, active) is ATP required?
active
which of the cell membrane transport pathways (passive/diffusion, facilitated, active) can transport against gradient?
active
facilitated IF coupled
which of the cell membrane transport pathways (passive/diffusion, facilitated, active) are substrate specific?
facilitated
active
examples of active transport
Na+/K+ ATPase
H+/K+ ATPase
examples of facilitated transport
simple glucose carriers
examples of secondary active transport
Na+/glucose carriers
Na+/amino acid carriers
examples of passive transport/diffusion
water, electrolytes, O2
how do cells too large for diffusion/active transport pass through the cell membrane
endocytosis
does endocytosis require ATP
yes
types of endocytosis
cell eating
- pinocytosis: engulfing small aprticles and extracellular fluid in a vesicle
- phagocytosis: same as above but larger material (bacteria, cell, etc)
what is exocytosis
release of vesicle filled with formerly endocytotic material
ex: toxins, neurotransmitters, hormones
what is osmolarity
conc of osmotically active particles in a solution; how “thick” is the solution
drives osmotic flow/pressure
osmolarity formula
O = g x C
g = # particles in solution C = concentration
hyperosmolic areas suck water IN/OUT?
IN
voltage gated vs ligand gated ion channels
voltage gated: activated by change in membrane potential
ligand gated: activated by hormone or second messenger (NT)
ion channels are based on…
channel size and ion distribution
excitable membrane potential is based on..
balance between ions in ICF and ECF; changes in those ion conc create AP generation and cellular activation
ICF: LOT OF K, LOT OF MG
ECF: LOT OF NA, LOT OF CA, CL
ex of simple squamous epithelium tissues
loop of henle
pulmonary alveoli
ex of simple cuboidal epithelium tissues
ovarian surface covering
gland ducts
ex of simple columnar epithelium tissues
absorptive lining of digestive tract
large ducts
(can be ciliated or non-ciliated)