Movement Across Membranes Flashcards
Transmembrane Proteins are hydrophilic or hydrophobic
Hydrophobic includes hydrophobic amino acids
Transmembrane proteins allow
Protein Protein interactions
What type pf molecules does the bilayer let flow freely through it
small molecules like H2o, O2,CO2,NO.
4 basic mechanisms for moving molecules across the membrane
1) simple diffusion
2) diffusion through a channel
3) Facilitated diffusion
4) Active transport
What is simple diffusion?
-Goes from high concentration to low concentration
-only for simple molecules
What is an aquaporin?
-A channel that is specific to water
-Water molecules move down in a single file gradient from a high concentration to low concentration.
What are channels?
-Formed by integral membrane proteins
-Selective
What are the two types of ion channels ?
1) Voltage-gated channels
2) Ligand-gated channels
Ion channels open when?
Due to a conformational change
- Voltage gate requires some type of charge to trigger opening
-Ligand gate requires binding of a specific molecule to trigger the gate to open
What is Curare?
-A competitive antagonist that binds to the ligand gate to prevent the actual molecule to bind causing the gate to not open.
Facilitated Diffusion?
Used for bigger molecules such as glucose
Two types of carriers
1) Symoporter
2) Antiporter
Active transporter?
-The conformational change is triggered by the hydrolysis of ATP
