Membrane Transport Flashcards
The pericardial membrane
Layer of flattened epithelial cells on top of connective tissue, phospholipids.
4 functions of the cell membrane
communication, barrier, structural support, material exchange
fluid mosaic model of a biological membrane (freeze fracture electro microscopy)
cholesterol molecules insert into the lipid bilayer, and there are also carb groups like glycoprotein and glycolipid.
Membrane compositon among different membranes in the body
They vary a lot among different types, but its protein, lipid and carbs.
Two parts that make up “extracellular fluid”
interstitial and plasma
What are the three main passive transport processes?
Simple diffusion, facilitated diffusion, osmosis
Describe simple diffusion, Ficks law and Membrane permeability
Ficks law:
Rate of diffusion: Surface area*membrane permeability *concentration gradient / membrane thickness
Membrane permeability: lipid solubility/ molecular size
Describe facilitated diffusion
using carrier proteins or channel proteins to transport lipophobic molecules
Describe osmosis
movement of water across a selectively permeable membrane (through lipid bilater or through aquaporins).
Carrier mediated transport competition
This is facilitated diffusion, can occur with the GLUT transporter (glucose and maltose) or in the treatment of gout (replacement of urea with probenecid) with the Organic anion Transporter (OAT) which sends uric acid nto the plasma
Leakage channels and gated channels
Both are involved in facilitated diffusion
define osmolarity
total concentration of solute particles.
What is the energy source for passive processes
kinetic
What is the energy source for passive processes
kinetic
Two types of active processes
active transport and vessicular transport
Primary vs secondary active transport, and the SGLT example
primary active transport is just using energy to transport something one way, like the sodium potassium pump. Secondary active transport uses concentration gradients to fuel movement of something against its concentration gradient. like the SGLT moving glucose into the cell by using the fact that sodium reaaaallly wants to enter the cell.
How does the sodium potassium pump work?
Three sodiums out, two potassium in, bind ATP right after sodium binds.
symport vs antiport
symport and antiport are involved in secondary active transport.
describe the transepithelial transport of glucose
- sodium enters the cell through its concentraiton gradient, and the glucose is able to use that momentum to get into the cell.
- sodium is then pumped out of the cell, and potassium is pumped in (NAK pump)
- glucose is pumped out of the cell basolaterally via GLUT
