Define plasma membrane in plants.
A selective barrier that regulates the entry and exit of substances in plant cells.
True or false: The plasma membrane is rigid and inflexible.
FALSE
The plasma membrane is fluid, allowing for movement and flexibility.
What is the primary function of the plasma membrane?
To control the movement of ions and molecules in and out of the cell.
Fill in the blank: The plasma membrane is made up of a _______ bilayer.
phospholipid
What role do proteins play in the plasma membrane?
They assist in transport, signaling, and maintaining the structure of the membrane.
Define selective permeability.
The ability of the plasma membrane to allow certain substances to pass while blocking others.
True or false: Cholesterol is found in plant plasma membranes.
FALSE
Cholesterol is primarily found in animal cell membranes.
What is the fluid mosaic model?
A model describing the plasma membrane as a dynamic and flexible structure with various proteins.
Fill in the blank: Transport proteins help in _______ substances across the plasma membrane.
moving
What are glycoproteins?
Proteins with carbohydrate chains that play a role in cell recognition and signaling.
Define cell signaling.
The process by which cells communicate with each other through signaling molecules.
True or false: The plasma membrane is impermeable to all substances.
FALSE
The plasma membrane allows selective passage of water, ions, and small molecules.
What is the role of aquaporins?
They are channel proteins that facilitate the transport of water across the plasma membrane.
Fill in the blank: Endocytosis is the process of _______ substances into the cell.
bringing
What is exocytosis?
The process of vesicles fusing with the plasma membrane to release contents outside the cell.
Define plasmodesmata.
Microscopic channels that connect plant cells, allowing for communication and transport.
True or false: The plasma membrane is involved in cell adhesion.
TRUE
Cell adhesion molecules help cells stick together and form tissues.
What is the function of lipid rafts?
They are microdomains in the plasma membrane that organize signaling molecules.
Fill in the blank: Cytoskeleton elements help maintain the _______ of the plasma membrane.
shape
What is the role of receptor proteins?
They bind to signaling molecules and initiate a cellular response.
Define membrane potential.
The voltage difference across the plasma membrane, crucial for cell signaling.
True or false: Passive transport requires energy.
FALSE
Passive transport occurs without energy input, relying on concentration gradients.
What is active transport?
The movement of substances against their concentration gradient, requiring energy.
Fill in the blank: Endocytosis can be classified as _______ or pinocytosis.
phagocytosis
