Lecture 3: Transporters and Pumps Flashcards
What is selective permeability?
It is the ability of the membrane to differentiate between different types of molecules, allowing some molecules while blocking others
List the types of molecules & if they are able to pass through the membrane
Pass: Hydrophobic molecules, small uncharged polar molecules
May pass or not: Large uncharged polar molecules
Will not pass: Ions
What is GDS?
GLUT1 Deficiency Syndrome
Name the mechanism of GDS
it is a genetic disorder that impairs brain metabolism. specifically, the brain is not supplied with sufficient glucose
Name symptoms of GDS
symptoms include: seizures, developmental delay, motor disorders
What is treatment of GDS?
ketogenic (high fat) diet
What does GLUT1 facilitate?
Facilitates the transport of glucose across the membranes of mammalian cells
T/F: GLUT1 is a uniporter
True
What does a uniporter do?
It has one or more specific binding sites for a solute (substrate), and will transport it across the membrane in a clothes pin fashion (if that makes sense)
The binding of solute induces a irreversible conformational
change in the transporter, GLUT1
(this is also specific to uniporters)
False, induces a reversible change
For a uniport, how is the direction of transport inversed?
Direction of transport is inversed if the direction of the
concentration gradient is changed
What is protein conformation determined by?
2 things
- Amino acid sequence of the protein
2. Interactions between individual amino acids
What bonds are involved in protein conformational change?
Via hydrogen bonds, salt bridges, disulfide bonds,
hydrophobic interactions
Name three ways that conformational changes are induced?
3 things
- binding of a ligand
- posttranslational modification of the protein
- change in the pH, voltage or temperature
Transporter-mediated transport reaches
a maximal transport rate known as ____.
Vmax