Exam 3- active transport and endocytosis Flashcards
what happens to the cell in hypertonic media?
cell shrinks as water moves out
what happens to the cell in hypotonic media?
Cell will absorb water and lyse
what happens to cell in isotonic?
nothing, water potential equal in medium and cytoplasm
What would happen to a cell if you were to add an inhibitor of the Sodium/Potassium pump?
The concentration gradients would slowly disappear and the concentration would equalize between the ions. Action potentials would cease to exist, resulting in non-functional nerve cells/muscle cells as well as no absorption of glucose
What are the ABC transporters?
Highly conserved ATP-binding cassettes.
what are the domains of ABC transporters?
2 ATP binding
2 transmembrane domains
what disease is associated to mutations in ABC transporters?
Cystic Fibrosis
What’s the genetic deficiency associated to Cystic Fibrosis?
Affects CFTR gene
What’s the molecular defect associated to Cystic Fibrosis?
Lack of function in Cl- channels, leading to abnormally thick, sticky mucus in respiratory and digestive tracks which leads to infection.
Why were the first trials for gene therapy against Cystic Fibrosis only partially successful?
The normal gene introduced did relieve some symptoms, but the normal immune response eliminated the adenovirus which in turn also eliminated the normal gene that had been introduced.
There are two types of Glucose Transporters in intestinal epithelial cells, one that acts by facilitated diffusion, and one that works by active transport. In which region of the plasma membrane is each one of them located? Why?
The active is at the apical domain of the cell, to allow glucose into the cell against its gradient. Uses symport with Na+
Active-Apical
Facilitated diffusion is at the basolateral domain of the cell. Glucose is able to pass down its gradient into the connective tissue and blood streamthrough uniport.
what is uniport
transport of 1 molecule across PM
what is antiport
the movement of an ion in the favorable direction is coupled off the movement of another ion in the opposite direction against its concentration.
what is symport
coupled transport of 2 molecules in the same direction across the PM
how do ABC transporters work?
Binds the ligand and hydrolyzes ATP to induce a conformational change to release the substrate on the opposite side of the membrane.
Importer and Exporter
