SBI 4U Biochemistry
ACTIVE TRANSPORT
BULK TRANSPORT

Some molecules are too ___ to cross through the cell membrane by __________ or ________ transport.

The cell has a specialized method of moving these substances ____ and ____ of the cell without
actually passing through the _______________________. The membrane actually _______ in on itself to
create a _____________________________ sac called a _________________.
Endocytosis

______________________________________________
There are three forms of endocytosis:
a) pinocytosis – _____________________________________________________________
b) phagocytosis – ____________________________________________________________
c) Receptor-assisted endocytosis
intake of ________________________________that bind to a _____________________________ on a protein in
the membrane e.g. ___________________
SBI 4U Biochemistry
Exocytosis

Bulk transport of material _______________________ the cell

A ___________ formed inside the cell moves to the ___________________ and _________ (joins) with the
_____________________, releasing its contents _________________ of the cell
e.g.
_______________________________________
Active Transport

requires a membrane _______________ protein (pump) and _____________ in the form of ____
(adenosine triphosphate).

How much energy is needed to move a substance into and out of the cell depends on how
________ the _______________________________________ is.
eg. [Ca+] in one compartment can be as much as ______X greater than another compartment this
is required for normal muscle function
1. Primary Active Transport

____________ of a cell’s energy requirements are for active transport

All primary active transport pumps move positively charged ions such as ___, ___, ____ and ____
Ex.
H+ (proton pump) moves H+ from cytosol to cell exterior pump temporarily binds to a
phosphate group removed from ATP
Ex.
Ca2+ pump moves Ca2+ from cytosol to cell exterior and into vesicles of ER
THE SODIUM - POTASSIUM PUMP
 Animal cells have a _____ [Na+] inside the cell and a __________[K+] inside the cell.
 These concentrations are maintained by pumping ____ Na+ out of the cell and ___K+ inside the
cell.
 The pump is a highly specific membrane protein channel.
 Pumping action involves changes to the protein __________ and is very rapid (300 Na+ per
second).
 Energy from ATP (adenosine triphosphate) drives the pump.
SBI 4U Biochemistry
2. Secondary Active Transport

_______________ and ____________ are accumulated by the cell ______________ a concentration
gradient.

Accomplished by coupling with _________ which pass simultaneously through a channel by
facilitated diffusion.

Special channel only allows ___________ back into the cell when a ______________ or an
_________________ is also bound the channel's exterior surface.

Occurs as a direct result of the activity of the ____________________ pump.

Symport  a _______________ moves through the membrane channel in the ___________
direction as the ___________________

Antiport  the transported _____________moves in the direction that is _______________
to the gradient of the ____________________ion