Cellular Communication

Which of the following correctly describes the reception stage of this signal transduction pathway?

• epinephrine binds to a g-protein coupled receptor protein present in the cell membrane

• the g protein changes shape, is activated, activates adenyl cyclase, which activates cAMP, which activates protein kinases

• protein kinases phosphoylate molecules

• glycogen synthesis is inhibited and glycogen breakdown is promoted

Which of the following correctly describes the transduction stage of this signal transduction pathway?

• epinephrine binds to a g-protein coupled receptor protein present in the cell membrane

• the g protein changes shape, is activated, activates adenyl cyclase, which activates cAMP, which activates protein kinases

• cAMP binds to the g-protein coupled receptor protein

• glycogen synthesis is inhibited and glycogen breakdown is promoted

Which of the following correctly describes the response stage of this signal transduction pathway?

• epinephrine binds to a g-protein coupled receptor protein present in the cell membrane

• the g protein changes shape, is activated, activates adenyl cyclase, which activates cAMP, which activates protein kinases

• cAMP binds to the g-protein coupled receptor protein

• glycogen synthesis is inhibited and glycogen breakdown is promoted

A signal molecule that binds to a plasma-membrane protein is a

• ligand

• second messenger

• protein kinase

• receptor protein

What type of signaling is shown here?

• autocrine

• synaptic

• endocrine

• paracrine

What do secondary messengers, like cAMP, do?

• transport a signal through the lipid bilayer

• relay & amplify a signal from the outside to the inside of the cell

• relay & amplify a message from the inside of the membrane throughout the cytoplasm

• dampen the message

A protein called Sonic Hedgehog plays a key role in vertebrate embryonic development. When this protein is released by secretory cells, it travels through the extracellular fluid and signals adjacent cells to go through the process of cell differentiation (process of cells becoming specialized). Sonic hedgehog is thought to be especially important for the development of the brain and limbs. What type of signaling is this an example of?

• Synaptic Signaling (Local)

• Paracrine Signaling (Local)

• Endocrine Signaling (Long Distance)

Which of the following statements best describes a primary function of plasmodesmata?

• They allow the movement of molecules from one cell to another, enabling communication between cells.

• They prevent the cell membrane from pulling away from the cell wall during periods of drought.

• They eliminate the need to produce signaling molecules and eliminate the need for cells to have receptors for signaling molecules.

• They increase the surface area available for attachment of ribosomes and thus increase protein synthesis.

This type of cell signaling will only be effective...

• over long distances (endocrine)

• when cells are in direct contact (juxtacrine)

• when responding to its own ligands (autocrine)

• if cells are nearby (paracrine)

Classify the image by their type of communication.

• Direct Contact (Animal Cell)

• Direct Contact (Plant Cell)

• Long Distance / Endocrine Signaling

• Local Signaling / Paracrine

• Local Signaling / Synaptic Signaling