Cell Signaling

The three main stages of cell signaling are...

• Response

• Transduction

• Reception

• Hormones

Second messengers are...

• signaling molecules that bind to cell-surface receptor proteins

• integral proteins that bind to signaling molecules

• small molecules and ions that relay signals received by cell-surface receptor proteins

• protein kinases

(2) examples of second messengers are...

• Ca 2+

• protein kinase

• cAMP

• G-protein coupled receptor

Select all that are true about cAMP.

• it is used to activate protein kinases in the signal transduction pathway

• it is broken down by phosphodiesterase

• it is a g-protein coupled receptor

• it is formed by adenylyl cyclase

Why do different target cells respond differently to the same signaling molecule (multiple choice).

• There are different response molecules in the cell

• There are different signal transduction pathways

• There are different receptors in plasma membrane

Which type of local chemical signaling system sends molecules from signaling cell to nearby target cell?

• Synaptic signaling

• Paracrine signaling

• Endocrine signaling

• Cell-cell recongnition

Why is a multistep pathway advantageous in the transduction pathway? (multiple choice)

• It creates gap junctions

• It increases the number of proteins activated in each step of the signaling cascade

• It leads to the production of a large amount of the target molecule (in the response phase)

• It creates a lot of receptor proteins

What are the two types of hormones and where are their receptors typically located?

• lipid soluble, binds to receptors in plasma membrane

• lipid soluble, bind to receptors in cytoplasm or nucleus

• water soluble, binds to receptors in plasma membrane

• water soluble, bind to receptors in cytoplasm or nucleus

If phosphorylation (of ATP or GTP) did not occur, what would happen?

• The ligand would bind, and the signaling pathway would proceed through transduction to cellular response.

• The ligand would bind, but the signaling pathway would not proceed through the transduction step.

• The ligand would bind and the signaling pathway would proceed through the transduction step, but would not produce a cellular response.

Choose all correct answer choices regarding the calcium ion.

• Acts as a second messenger in the signal transduction pathway

• Is found in low concentrations outside the cell

• Is released from the mitochondria and endoplasmic reticulum when a cell signaling molecule binds to a cell-surface receptor

• Is found in low concentrations in the cytoplasm

Tags

NGSS.HS-LS1-3