active transport chapter 7 biology

active 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?