Active Transport Flashcards
Active transport
cell uses ENERGY to transport molecules. ( because moving AGAINST gradient)
Movement from an area of LOW solute concentration to an area of HIGH solute concentration.
How are they moved
molecules are moved across the membrane
- by transport or carrier protein
- specific to the substance being transported
How are protein pumps used
Transport proteins and ions against concentration gradient ( active - uptake)
How is a carrier protein used
Binding to the specific molecule on one side of the membrane.
Changing shape to move the molecule across.
Releasing the molecule on the other side.
How does it compare to diffusion?
Where does active transport (active uptake) occur on the cell membrane?
Active transport occurs in the cell membrane at specific carrier proteins (pumps).
What are the different types of active transport (bulk transport)
Bulk transport = main types of movement of large substances or groups of substances
Protein Pump
Endocytosis
Exocytosis
Endocytosis
The transport of substances into the cell ( cell engulfment) eating
- Cell membrane folds around around the substances to form a VESICLE
2 types:
Pinocytosis
Phagocytosis
Pinocytosis
( cell drinking)
plasma membrane engulfs a droplet of liquid and releases it into the cell
Phagocytosis
( cell eating)
Solid objects are engulfed by plasma membrane.
E.g. white blood cells
these vesicles can fuse with LYSOSOMES which contains enzymes to digest the contents of the vesicle
Exocytosis
substances OUT of cell
Such as Hormones, enzymes waste
Material is enclosed into a vesicle at the Golgi bodies
vesicle moves to the membrane and FUSSES with it.
Contents are released into the external environment. Eg Neurotransmitters
EXOCYTOSIS IN THE NERVOUS SYSTEM
A nerve cell communicates to another cell by releasing chemicals (NEUROSTRANSMITTERS) via exocytosis into the synapse.
(the gap between two neurons).
