CH - 6 CELL COMMUNICATION

4 MAIN PROCESSES

signal transmission : reception : signal transduction : response

SIGNAL TRANSMISSION

cell must synthesize and release signaling molecules

RECEPTION

large proteins that bind with specific signaling molecules (binds on the surface of the cell)

SIGNAL TRANSDUCTION

a cell convert extracellular signal into an intracellular signal and relays the signal

RESPONSE

alteration of some cell process

WAYS CELLS COMMUNICATE

chemical : electric/energy : temporary contact : junctions

CHEMICAL SIGNALS

interleukins : neurotransmitters : growth factors : hormones

INTERLEUKINS

involved in communication between cells of the immune system

NEUROTRANSMITTERS

signal between neurons of the nervous system

GROWTH FACTORS

stimulate cell growth, division, and development

HORMONES

regulate sexual development and reproduction

LOCAL CHEMICAL TRANSMISSION

a local regulator diffuses to target cells

DISTANT CHEMICAL TRANMISSION

hormones are transported to distant target cells

ELECTRICAL/ENERGY SIGNALS

-Cells in the ear receive sound waves and convert them to electrical signals

-Cells in the eye receive light waves and convert them to electrical signals

-Neurons relay electrical impulses and in some cases can send and receive electrical signals

TEMPORARY CELL-CELL CONTACT

cell adhesion molecules (CAM) on the surface of certain immune system cells allow for cells to home to sites of damage and infection

DIRECTLY THRU CELL JUNCTIONS

some cells are joined with junctions allowing signals to flow freely between their cytoplasms

LIGAND

binds to a specific receptor and triggers a response

HYDROPHILIC MOLECULES

bind to protein receptors on the surface of target cells

HYDROPHOBIC MOLECULES

move through the plasma membrane and bind with intracellular receptors found in the cytosol or nucleus

RECEPTOR UP-REGULATION

increases the number of receptors synthesized, and amplifies the signaling molecule's effect

RECEPTOR DOWN-REGULATION

transporting receptors to lysosomes, where they are destroyed

ION CHANNEL-LINKED RECEPTORS

found in the plasma membrane; convert chemical signals into electrical signals; ion channel opens or closes in response to binding of the signaling molecule

G-PROTEIN LINKED RECEPTORS

transmembrane proteins with an outside binding site for a signaling molecule, and an internal binding site for a specific G protein; couple signaling molecules to transduction pathways in the cell

ENZYME LINKED RECEPTORS

transmembrane proteins with a binding site for a signaling molecule outside the cell and an enzyme component inside the cell

TYROSINE KINASE

an enzyme that catalyzes the transfer of phosphate groups from ATP to the amino acid tyrosine on a substrate protein

PROTEIN KINASE

adds phosphate to activate a target

PROTEIN PHOSPHATASE

catalyzes the removal of a phosphate group

INHIBITS NEURAL SIGNALING

GABA \______ when chloride ions enter the cell

INACTIVE

when \_______ G protein has one subunit linked to a GDP

GTP

signaling molecule binds to receptor & GDP is replaced by GTP

GTP RELEASES

energy

G PROTEIN IS

deactivated

FIRST

the signaling molecule is the \______ messenger

SECOND

information relayed by G protein to a \______ messenger

SECOND MESSENGER

amplify signals inside the cell

CYCLIC AMP (cAMP)

is a second messenger

PHOSPHOLIPIDS

some G proteins use \______ as second messengers

PIP2

splits into IP3 and DAG

CALCIUM IONS

used for neural signaling by binding to certain proteins that activate enzymes

CALMODULIN

helps regulate metabolism, muscle contraction, memory, inflammation, and apoptosis

GENE EXPRESSION REGULATION

ligand-receptor complex binds to region of DNA → activates/represses genes

INTEGRINS

transmembrane proteins that transduce signals in two different directions

ION CHANNELS

open or close (ex: neurotransmitters)

ENZYME ACTIVITY

is altered (ex: receptors on site blood cells)

SPECIFIC GENE ACTIVITY

may be turned on or off

G-PROTEINS

some tyrosine kinase receptors activate \_______

RAS PROTEINS

small G proteins that are active when bound to GTP

MAP KINASE PATHWAY

proteins in the MAP pathway phosphorylate combines to form a transcription factor