Lecture 5 Flashcards
Molecules can be transported…
actively or passively
What does active transport requires that passive doesn’t?
energy
what is concentration gradient?
the difference in concentration of a substance from one location to another.
In passive transport, the molecules travel…
from an area of high concentration to an area of lower concentration
Active transport, the molecules travel…
from low concentration to high concentration
What is simple diffusion?
Small, nonpolar molecules can easily cross
the phospholipid bilayer as they interact well
with the hydrophobic region of the
membrane,
What is diffusion?
A form of passive transport
What is facilitated diffusion?
Larger charged and polar particles such as
ions (Cl-) and glucose need protein channels
(nonspecific) or carriers (specific) to diffuse
into the cell.
What is the rule of diffusion?
Substances ALWAYS travel from the area of
highest concentration to areas of lower
concentration, until equilibrium is reached.
Channel proteins generally carries ___ across the membrane
ions
What does carrier protein relies on?
concentration gradient
What determines the rate of carrier proteins?
the number of carriers present in the
membrane as the carrier
What is osmosis?
the term which refers to the diffusion
of water across a membrane
Most water uses a channel protein known as…
aquaporin
In terms of solute concentration water moves…
from the hypotonic to the hypertonic
environment
