Biology 1A03- Chapter 6 Questions
8. The differences between simple diffusion and osmosis are:
Simple Diffusion Osmosis
Molecules in a beaker diffuse freely Osmosis deals with water moving
across a bilayer. along its concentration gradient; from
Solutes diffuse across the membrane; lower to higher concentration.
each undergoes a net movement along Osmosis is a special case of diffusion.
its own concentration gradient. Start with more solute on one side
Equilibrium is established. than the other; using molecules that
Solutes continue to move back and cannot cross the selectively permeable
forth across the membrane but at membrane.
equal rates. Dilutes the side of higher
Does not require a membrane concentration.
HIGH concentration to LOW From a LESS concentrated solution to a
concentration. DOWN A MORE concentrated solution.
9. The differences between simple diffusion and facilitated diffusion:
Simple Diffusion Facilitated Diffusion
Diffusion occurs from an area of HIGH Is assisted by a specific TRANSPORT
concentration to LOW concentration. PROTEIN
This diffusion occurs without the Concentration gradient dependent.
assistance of any intermediary Some molecules and ions such as
molecule (protein). glucose, sodium ions and chloride ions
Molecules diffuse freely across a are unable to pass through the lipid
phospholipid bilayer. bilayer of cell membranes.
10. The differences between a hypertonic solution and a hypotonic solution are:
Hypertonic solution Hypotonic solution
A solution with a greater solute A solution with a lower solute
concentration than that inside the cell. concentration than that inside the cell.
If the solution outside the membrane If the solution outside the membrane
has a higher of solutes than the interior has a lower concentration of solutes
has, and the solutes are not able to than the interior has, water will move
pass through the lipid bilayer, then into the vesicle via osmosis. The
water will move out of the vesicle into incoming water will cause the vesicle
the solution outside. to swell or burst.
11. The differences between the Davson-Danielli Sandwich model and the Singer-Nicholson
Fluid Mosaic model are:
Sandwich model Fluid Mosaic model
Structured like a sandwich, with The discovery of amp