Active Transport Flashcards
Active processes
1) Primary transport
2) Secondary transport
3) Vesicular transport
Primary Transport
• Energy derived from ATP
• Changes shape of transporter protein
- pumps substance across plasma membrane against its concentration gradient
Secondary Transport
• Energy stored in concentration gradient
- hydrogen or sodium
• Used to drive other substances against their own concentration gradients
Vesicular Transport
- Receptor-mediated Endocytosis
- Phagocytosis
- Bulk Phase Endocytosis (Pinocytosis)
Exocytosis
membrane-enclosed secretory vesicles fuse with plasma membrane
• release their contents into extracellular fluid
Transcytosis
combo of endocytosis & exocytosis
• used to move substances from… 1 side of a cell —> across it —> out other side
Active Processes
Movement of substances against a concentration gradient; requires cellular energy in the form of ATP. Low —> High
1) Active Transport
- Cell uses-up energy to move a substance across membrane against its concentration gradient
- by transmembrane proteins ; function as carriers
Active transport transports
Polar / charged solutes
2) Primary active transport
- Substance moves across membrane against its concentration gradient
- by pumps (carriers) that use energy supplied by hydrolysis of ATP
Primary active transport transports
Na+, K+, Ca2+, H+, I−, Cl−, & other ions
3) Secondary active transport
- Coupled active transport of 2 substances across membrane
- using energy supplied by a Na+ or H+ concentration gradient
- maintained by primary active transport pumps.
Secondary active transport transports
Antiport: Ca2+, H+ out of cells
Symport: glucose, amino acids into cells
4) Transport in Vesicles
- Substances move into or out of cells in vesicles coming from plasma membrane
- requires energy from ATP
