foundation 1 Flashcards
about what percent of the plasma membrane is lipids?
50
how can facilitated diffusion take place through a membrane?
pores/channels (non gated)
gated channels
carriers (uniports)
what are the 2 ways secondary active transport can take place?
co-transporters (symporters)-movement of solutes in same direction
counter-transporters (antiporters) movement of solutes in opposite direction.
what are the 4 ways something can move through a membrane?
passive diffusion
facilitated diffusion
secondary active transport
primary active transport
what is the driving force of passive diffusion?
electrochemical gradient
how do uniporters work?
change conformation to move a solute through PM to other side.
how do non gated channels work?
integral protein that provides direct access to the cell-like a pore.
what are some examples of non gated channels?
porins in bacteria
mitochondrial porins
nuclear pore complex
aquaporins
what are some stimuli that cause gated channels to open?
voltage
mechanical
ligand binding
what are some examples of carrier proteins?
GLUT1-red blood cells
GLUT2-intestine
GLUT4-skeletal and cardiac muscles
what does flux mean?
flow/movement
what is an example of a symporter/cotransporter?
Na+/glucose transporter (SGLT)
what is an example of an antiporter/counter transporter?
NHE (Na+/H+-sodium proton exchanger)-important for maintaining cytosolic pH.
what are the 4 main types of active transporter?
P-type ATPase
F ATPase
V-ATPase
ABC transporters
what type of transporter is CTFR?
ABC active transporter
how do active transporters work?
domain in transporter protein binds to atp-it hydrolyses-energy released used to create conformational change in in protein which moves solute against conc gradient.
what is p glycoprotein?
an important active transporter which moves things out of cells.
why is p glycoprotein important?
it’s overexpressed in cancer cells. has a wide range of substrates inc cancer drugs which leads to the drugs having no impact on cancer cells-big issue in multidrug resistant cancers.
how does CTFR work?
it’s an active transporter but it uses atp to open a channel and then chloride ions move down their conc gradient.
what happens in the Na+/K+ pump?
3Na+ out
2K+ in
(high K+ in the cell and high Na+ outside)
what is ICF?
intracellular fluid-the fluid inside cells.
what is ECF and its components?
extracellular fluid-fluid outside cells:
plasma volume
interstitial fluid
transcellular fluid
what is plasma volume?
fluid not in cells in the blood present in the intravascular compartment.
what is the intravascular compartment?
cardiac chambers+blood vessels