5.4 Active Transport Flashcards
What is active transport
Movement of molecules into and out of a cell from a region of low concentration to high concentration
Requires energy and carrier proteins
What is teh metabolic energy supplied by
ATP
How do Carrier proteins help active transport
Span the membranes and act as pumps
What happens in the first steps of active transport when a cell travels from the outside go teh inside of a cell
Molecule binds to receptors in the channel of teh carrier protein
On the outside of the cell ATP bind to carrier proteins
What happens to ATP when it binds to teh carrier protein
Hydrolysed into ADP and phosphate
What does the phosphate molecule do after ATP is hydrolysed
It binds to the carrier protein causing the protein to change shape and open up the inside of the cell so the molecule is released into the inside of the cell
Phosphate is then realised from the carrier protein recombined with ADP to form ATP
What is bulk transport
Another form of active transport for large molecules that cannot move through channel or carrier proteins
What enzymes are used in bulk transport
Enzymes
Hormones
Whole cells like bacteria
What’s teh difference of endocytosis and exocytosis
Endo = bulk transport of material into cells Exco = bulk transport of material out of cells
What are teh 2 types of endocytosis
Phagocytosis for solids
Pinocytosis for liquids
What happens in endocytosis
Cell surface membrane invaginates when it comes into contact with material to be transported
Membrane enfolds the material until eventually the membrane fuses which forms a vesicle
Vesicle pinches off and moves into cytoplasm
What happens in exocytosis
Vesicles forked by Golgi apparatus move towards and fuse with cell surface membrane
What is energy in the form of ATP required for in bulk transport
Movement of vesicles along cytoskeleton
Changing shape of cells to engulf materials
Fusion of cell membranes as Vesicles form or meet cell membrane
