Cellular communication reading guide Flashcards
(12 cards)
What are motor proteins? Give some examples and describe their functions.
Motor proteins are proteins that generate movement within cells. Myosin is a motor protein that enables actin to engage in cellular events that require motion like cell division.
Describe the structure and function of the extracellular matrix (ECM).
Interwoven collagen fibers and proteoglycans hold cells together to form a tissue, and allow cells within that tissue to communicate with each other.
What are the functions of plasmodesmata?
numerous channels that pass between adjacent plant cells’ cell walls that connect their cytoplasm and enable transport of material from cell to cell
What are the functions of tight junctions?
watertight seal between two adjacent animal cells. Proteins hold the cells against each other.
What are the functions of gap junctions?
channels between adjacent cells that allow for transport of ions, nutrients, and other substances that allow cells to communicate in animal cells.
What are the functions of desmosomes?
spot welds between adjacent epithelial cells in animal cells and maintain cells in a sheet-like formation that stretches.
What are ligands?
signaling molecules that interact with target cells that are affected by chemical signals
What are internal receptors?
responds to hydrophobic ligand molecules that travel across the plasma membrane.
What are cell surface receptors?
membrane-anchored proteins that bind to eternal ligand molecules and perform signal transduction.
Provide an example of a hydrophobic ligand and a water-soluble ligand.
testosterone (hydrophobic) binds to receptors inside the cell, and epinephrine (hydrophilic) binds to receptors on the cell surface
Explain how ion-linked receptors function.
binds a ligand and an open channel through the membrane to allow specific ions to pass through. It has an extensive membrane that spans the region and is hydrophobic in nature. Aminoc acids line the inside of the channel and are hydrophilic and allow for the passage of water ions. The protein changes structure when a ligand binds to the extracellular region and allows for ions to pass through.
Explain how G-protein coupled receptors function.
Binds ligands and activates g-proteins that then interact with an ion channel or an enzyme. Before the ligand binds, the inactive g-protein binds to a site on the receptor and changes shape, and activates the g-protein that releases GDP and picks up GTP. The subunits of the g-protein split into an alpha subunit and a beta subunit. The GTP on the active alpha subunit is hydrolyzed to GDP and the beta subunit is deactivated.
