5.4 Protein Mediated Transport Flashcards
What is simple diffusion, and what types of molecules does it involve?
allows lipophilic molecules to cross cell membranes without assistance.
What is mediated transport?
involves membrane proteins that help lipophobic or charged molecules cross cell membranes
What is facilitated diffusion, and does it require energy?
a passive process that moves molecules down their concentration gradient without using energy.
What is active transport, and does it require energy?
Active transport moves substances against their concentration gradient and requires energy, such as ATP
What are the functions of structural proteins in the cell membrane?
Structural proteins create cell junctions, connect to the cytoskeleton, and attach cells to the extracellular matrix.
What role do enzymes play on the cell membrane?
Membrane enzymes catalyze reactions on the cell surface or inside the cell.
What do receptor proteins do?
Receptor proteins bind with ligands to trigger cellular responses.
What is the function of channel proteins?
form open, water-filled passageways that allow ions and water to cross the cell membrane.
How do carrier proteins transport molecules?
bind to specific molecules and change conformation to transport them across the membrane.
What are the types of gated channels?
chemically gated, voltage-gated, and mechanically gated.
What is the difference between symporters and antiporters?
Symporters move two or more molecules in the same direction, while antiporters move molecules in opposite directions.
What is the role of the CFTR channel in cystic fibrosis?
The CFTR channel transports chloride ions across epithelial cells, and its malfunction can lead to cystic fibrosis.
