Unit 4 - 4.1 Cell Communication

Identify a message communicated by direct cell-to-cell contact. What occurs during this process?

a key message communicated by cell-to-cell contact is cell recognition. during cell recognition, cells identify and interact with each other. for example, the B-cells in the immune system attach to an antigen on an infected cell.

Identify a message communicated by chemical signaling. What occurs during this process?

a message communicated by cell signaling is the target cell is able to send a signal to the receiving cell. it can either be long distance (diff. cell) or short distance (same cell type). for example, neurotransmitters can travel across the synapse and attach to the target cell or when insulin is released by the pancreas, signaling cells to take up glucose from the bloodstream and regulating blood sugar levels.

How do cells communicate over a short distance? Identify two examples.

cells communicate over a short distance as the cell sends out local regulators (signals) they are received by a cell of a similar type not too far away. two examples are paracrine and synaptic signaling.

How do cells communicate over long distances? Identify one example.

in long distance cell communication, cells send out a signal further to a different area with cells that are a different type. an example is endocrine signaling which is when cells release hormones into the bloodstream which allows the message to travel through the body and reach distant cells. an exact example is adrenaline (epinephrine) which is released by the adrenal gland and activates our fight or flight response.

What is the process that results in the release of chemical signal from a cell?

the process that results in the release of chemical signals from a cell is exocytosis.

Where are the chemical signals synthesized?

chemical signals are synthesized in the endoplasmic reticulum. the ER is the “factory” where the signals are made.

Where are the chemical signals processed?

after synthesis, the chemical signals are processed in the Golgi apparatus which are then transported to the membrane via vesicles. the Golgi “packages” the signals.

What occurs during reception?

during reception, the signaling molecule binds to its receptor, causing a change that starts the signaling process.

Where is the receptor for a steroid hormone?

the receptor for a steroid hormone is inside the cell since steroids can pass through the cell membrane (lipid-soluble, nonpolar).

Where is the receptor for a protein hormone?

the receptor for a protein hormone is outside of the cell since it cannot go through the membrane (water-soluble, polar).

True or False: Only specific cells will respond to specific chemical signals because they have a receptor for the chemical signal.

True. Only specific cells will respond to specific chemical signals because they have the right receptors for those signals.