Maintaining Homeostasis

Describe the cell when the body is in a state of equilibrium.

Inside the cell: lots of K, small amount of Na, Cl, Ca. Outside the cell: lots of Na, Cl, Ca, small amount of K.

What does the internal environment refer to?

interstitial fluid, cells and blood

What does the external environment refer to?

any part of the body that is contiguous with the outside

The hydrophobic region allows…

lipid-like substances to pass

non-polar substances to pass

the hydrophobic region inhibits…

water-loving substance to pass

polar molecules to pass

What are the functions of the cell membrane?

1. physical isolation

2. structural support

3. transport nutrients + waste

4. cellular communication

What is diffusion?

Moving from an area of high concentration to an area of low concentration

__________requires ATP to move substances against their concentration gradient.

active transport

_____ carriers transport only 1 kind of substrate.

uniport

_____ carriers move two or more substrates in the same direction across the membrane.

symport

______ carriers move substrates in opposite directions.

antiport

What is an example of active transport?

sodium potassium pump

_______ transport uses an electrochemical gradient created by primary transport as its energy source

secondary active

What is the osmolarity of the ECF and ICF?

290mOsM

_______ is the net movement of water across a selectively permeable membrane driven by a difference in solute concentrations on the two sides of the membrane.

Osmosis