Osmoregulation: Guided Notes
Directions: Fill in the blanks below.
-Let’s take it back a step
Osmosis is an example of __________________________________.
Passive transport is the movement of molecules across a cell membrane with ________
___________________________________.
Ie. Osmosis, Diffusion, Facilitated Diffusion
-Check for understanding
Why is osmosis considered to be an unique example of passive transport?
Molecules in Passive Transport
● Molecules that are able to freely pass the cell membrane
○ _______________________
○ _______________________
○ _______________________
-Components of the Cell Membrane
● HYDROPHILIC
○ Having a tendency to ___________________________ by
water.
● HYDROPHOBIC
○ Having the tendency to ___________________________
water.
-Facilitated Diffusion
Facilitated diffusion is the movement of substances across a cell membrane by ______
_______________________ that use no energy.
-Protein Involvement
● _____________________
○ A transport protein that is specific for a molecule, or group of substances.
■ Ie. ATPase, ABC Transporters etc.
● ______________________
○ A type of transport protein, acts like a pore in the membrane that lets
water molecules or small ions through quickly
● ________________________
○ A transport protein that opens a "gate," allowing a molecule to pass
through the membrane. Gated channels have a binding site that is specific
for a given molecule or ion.
■ Ie. Sodium-potassium pump
-Facilitated Diffusion Cont’d
● Concentration Gradient
○ The gradient creates potential energy which increases as the
concentration difference increases, which results in faster diffusion.
● Temperature
○ Carrier transport rates increase more rapidly with temperature.
● Saturation
○ Since the number of carrier proteins in the membrane is limited, once all
the proteins are bound, they can no longer bind more molecules.
● Selectivity
○ There is a reciprocal relationship between the transport rate and the
selectivity of the transport process.
-What is ATP?
● Adenosine triphosphate, abbreviated usually ATP
○ Is an important “______________________” found in all life forms
● ATP is the energy form for cells.
○ It is one of the byproducts of Cellular Respiration and the breakdown of
__________.
-Sodium-Potassium Pump
Sodium-Potassium pump is a transport system in a biological membrane where
________ Na+ ions are taken out while _________ K+ ions are taken into the cell
against their respective concentration gradients.
-What Does It Do?
● In the Kidneys specifically, it helps maintain osmoregularity.
○ It does this by automatically having salt leave a cell when a cell begins to
swell.
○ Function is to pump ____________ sodium ions out of the cells and
________________ potassium ions within the cells
-Let’s Figure It Out
1. What is going on here?
2. On a cellular level, what process/es are preventing homeostasis in the muscle
cells here?