Cell Transport

WHAT IS Homeostasis? Cells try to maintain a relatively constant internal environment. This is known as HOMEOSTASIS

Things our Body Regulates pH TEMPERATURE BLOOD GLUCOSE WATER ( in cells and tissues) Blood pH between 7.35 -7.45 37 C ( 98.6F) Up to 100mg/dL

Types of Cell transport- HOW THINGS MOVE Diffusion – movement of molecules from an area of HIGH concentration to an area of LOW concentration.

The semipermeable membrane… Our cell membrane and other substances are SELECTIVELY or SEMI PERMEABLE The will let some things in and not others. Some are small enough to squeeze through holes or small PORES Some substances will need HELP to cross the membrane.

Diffusion with help… Facilitated diffusion involves the use of a transport protein to get the molecules to move from an area of HIGH concentration to an area of LOW concentration.

OSMOSIS – Diffusion of Water WATER moves from an area where there are LOTS of water molecules to an area where that are FEW water molecules.

The RESULT of water movement

Things to help you understand OSMOSIS SALT “SUCKS” – the more salt the more the water will be SUCKED across WATER IS MOVING- It moves from LOTS of free water to an area with less free water

Active vs Passive Transport No ATP HAPPENS SPONTANEOUSLY DOWN THE CONCENTRATION GRADIENT Diffusion, osmosis and Facilitated diffusion are all types ACTIVE ATP is NEEDED HAPPENS WITH ENERGY UPHILL, UP THE CONCENTRATION GRADIENT Endocytosis, pinocytosis, phagocytosis, exocyotosis are all types

ACTIVE TRANSPORT This needs ENERGY in the form of ATP to occur. This moves things from an area were there are very few of that kind of molecule to where there are LOTS.

The SODIUM POTASSIUM PUMP ACTIVE TRANSPORT REQUIRES ENERGY The SODIUM POTASSIUM PUMP