plasma membranes Flashcards
1
Q
roles of cell surface membranes
A
- separates cell components from external environment
- regulates transport of materials into/ ex cells
- site of cell communication
- site of chemical reactions
2
Q
role of intracellular membranes
A
- compartmentalisation - separates organelles, providing different conditions for specific reactions
- isolate harmful substances
- formation of transport vesicles
- increase SA
- site for chemical reactions e.g thylakoid membrane - photosynthesis
3
Q
active transport
A
movement of substances from low to high concentration against concentration gradient using ATP and carrier proteins
4
Q
endocytosis / exocytosis
A
bulk transport of large substances into/ out of cell
- segment of plasma membrane surrounds substance and encloses it into a vesicle
- energy from ATP moves the vesicle
exocytosis extra bit
- ATP fuses vesicle to membrane
- opening in membrane = substance secretion
