1
how does facilitated diffusion work - ANSWERS-molecules bind to
molecules to a transmembrane protein on one side of a membrane and
are then taken to the other side
what are the characteristics of a carrier protein - ANSWERS-
transmembrane protein
has binding sites for specific particles
binding occurs one side at a time and conformational changes occur
what factors affect facilitated diffusion? - ANSWERS-the number of
carrier proteins
the concentration gradient
rate of transport of each carrier
primary active transport - ANSWERS-uses ATP to directly transport a
substance
secondary active transport - ANSWERS-powered by a chemical or
electrical gradient created by primary active transport.
vesicular transport - ANSWERS-this is active transport of material in
or out of the cell through the plasma membrane
,what are the two types of vesicular transport - ANSWERS-
endocytosis
exocytosis
what is endocytosis? - ANSWERS-brings the material into the cell
what is exocytosis? - ANSWERS-A process in which a vesicle in the
cytoplasm of a cell fuses with the plasma membrane and releases its
contents from the cell; used in the elimination of cellular wastes and
in the release of gland products and neurotransmitters.
provides cell a way to secrete large molecules
enables cells to add specific components to membrane
Paracrine/autocrine - ANSWERS-communication with neighboring
cells
Hormones - ANSWERS-released from glands into blood. Long
distance signal (also takes longer to communicate)
What are the three receptor properties? - ANSWERS-specificity
saturable
competable
, agonist - ANSWERS-ligand that binds to a receptor to cause a
biological purpose
What is a ligand - ANSWERS-a substance that forms a complex with
a biomolecule to serve a biological purpose
antagonist - ANSWERS-ligand that binds to a receptor and does NOT
cause a biological response
can OUTCOMPETE a endogenous ligand
lipophobic messengers - ANSWERS-Lipophobic messengers depend
upon receptors in the plasma membrane facing the extracellular
environment because of the lipids in the plasma membrane repel them
what are some examples of lipophobic messengers? - ANSWERS-
Peptide Hormones & Catecholamines
how do lipophobic messengers work? - ANSWERS-bind to cell
surface receptors which triggers transduction pathways that open
channels, activate or deactivate enzymes, etc.
what is a channel linked receptor? - ANSWERS-they work by
opening channels to cause ion flow that leads to a response