Lecture 5 Flashcards
(25 cards)
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
What is hydrostatic pressure?
the pressure of the
cytoplasm against the membrane
What is osmotic pressure?
the force of water
trying to enter the cell
What are uniporters?
carrier in active transport that transports one
molecule in one direction
what are symporters?
two
molecules in the same direction
what are antiporters?
two molecules in two directions
what is endocytosis?
the process by which the cell
will take in “large” quantities of material via
membrane vesicles
what is pagocytosis?
occurs when the cell takes up
solid matter, such as immune cells engulfing
pathogens
what is pinocytosis
is the engulfment of liquid
what is receptor mediated endocystosis?
Receptor mediated endocytosis occurs when
specific molecules bind to cell surface
receptors, and are then ingested by the cell
