Studied by 4 peopleactive transport
the transport of a substance across the cell membrane against its concentration gradient
requires energy
active transport...
low --> high concentration
active transport
ATP
the energy needed for active transport is supplied by ______
the substance is being moved
why does active transport require energy?
sodium potassium pump
one of the most important pumps in animal systems
muscle and nerve cells
where does the sodium potassium pump occur
4
how many steps does the sodium potassium pump contain?
step 1
3 sodium ions bind to the pump from the inside of the cell; ATP ---> ADP + P + energy
step 2
phosphate group attacks the pump causing the pump to change shape and eject 3 sodium ions out of the cell
phosphorilation
phosphate group attaches to pump
step 3
2 potassium ions bind from outside the cell to pump
step 4
phosphate detaches from pump; 2 potassium ions and released into the cell
dephosphorylation
phosphate detaches from the pump
3 sodium ions
2 potassium ions are pumped in for every...
positive
more _______ ions exit than enter the cell
against
ions are pumped ________ the concentration gradient
vesicle
cells move really large molecules in and out of the cell with a _____
carrier proteins
many substances are too big to be transported by ________
endocytosis
the movement of a substance into a cell by vesicle is called ______
exocytosis
the movement of a substance by a vesicle to the outside of a cell is called _______
into
in endocytosis, cells move molecules _____ the cell
2
how many ways of endocytosis
pinocytosis
"cell drinking", takes in dissolved molecules as a vesicle
phagocytosis
"cell eating", used to take in large particles and turn them into vesicles
lysosome
vesicle fuses with a ______ to digest the bacteria or food particle
cell membrane
molecules are moved out of the cell by vesicles that fusse with the
golgi body
what organelle does the vesicle originate from?
Note 
Flashcard (25)