Cellular Movement Flashcards
What is bulk flow
water molecules moving together as a group as a result of potential energy
What is the water potential
potential energy of water
what is the hydrostatic pressure
measures in terms of pressure required to stop the bulk flow of water
why is water rarely pure
exists as a mix of solutes and solvent
What is a solute
substances dissolved into solution
What is a solvent
main component of the solution
What is diffusion
movement of solute molecules in a solvent in order to result in the equal distribution of solute molecules in the solvent
What is a concentration gradient
differences on solute concentration over a distance
What is osmosis
movement of water across a semi-permeable membrane
higher water potential to lower water potential
What is osmotic pressure
pressure required to stop water movement resulting from osmosis
- what helps keep plant cell turgid
Which compounds can freely diffuse across plasma membrane
some gasses and small uncharged molecules
What are integral membrane proteins
- very selective proteins
- specialized in transporting compounds
What are the two classes of integral membrane proteins
facilitated transport, active transport
What is facilitated transport
- type of passive transport
- generally follows an electrochemical gradient
What are the two types of facilitated transport
Channel, carriers
What are channel proteins
- water filled pores that extend across the plasma membrane
- open and close to allow passage of solutes
What does gating the channel mean
closing the passage of solutes
What is Aquaporin
- open channel protein specialized in the transport of water across plasma membrane
- allows for rapid passage of water into or out of the cell
What are carrier proteins
type of cotransport
What is symport
two solutes moving down their electrochemical gradient in the same direction
What is antiport
two solutes moving down their electrochemical gradient in opposite directions
What is Active transport
uses energy to transport compounds
What are the two types of active transport
primary active transport,
secondary active transport
What is primary active transport
ATP directly spent to pass another compound across the plasma membrane
What is secondary active transport
type of cotransport
- one solute carried down its electrochemical gradient and one is carried against its electrochemical gradient
What are the systems to transport large molecules
vesicles
plasmodesmata
What is a vesicle
an invagination of the plasma membrane to construct a circular transport structure
What are the 3 main roles
phagocytosis, pinocytosis, receptor-mediated endocytosis
What is phagocytosis
- cell-eating
- example of endosymbiosis
- containment of very large macromolecules and other organic debris for breakdown
What is pinocytosis
cell-drinking
- example of endosymbiosis
What is receptor-mediated endocytosis
- specific membrane proteins serve as receptors
- respond to specific signals by forming a vesicle around the received molecules
- help guide vesicle to specific destination
what are coated vesicles
specialized peripheral proteins
What is the plasmodesmata
- narrow strands of cytoplasm that connect the protoplasts of neighbouring cells
What are the three main pathways of movement between cells
symplastic, apoplastic, transcellular
What is symplastic transport
- through the cytoplasm
- crosses through plasmodesmata
- passive
What is apoplastic transport
- through the cell wall matrix
- cannot pass casparian strip
passive
What is the Casparian strip
cell that limits the uptake of water into the vasculature of higher plants
What is transcellular transport
- passes through the vacuole
- crosses with membrane transporters
- active
