Chapter 6: Cell Communication

DAG

________ is a second messenger that activates certain protein kinase enzymes.

tyrosine kinases

Many enzyme- linked receptors are ________ in which the enzyme is part of the receptor.

ion channels

In response to signaling molecules, ________ open or close, enzyme activity changes, leading to metabolic changes and other effects, and specific genes are activated or repressed.

Adenylyl cyclase

________ catalyzes the formation of cyclic AMP (cAMP) from ATP.

hydrophobic molecules

Their ligands are small, ________ that diffuse across the plasma membrane.

Ligand

When a(n) ________ binds with the receptor, the GDP is released and is replaced by guanosine triphosphate (GTP)

Calcium ions

________ can also act as second messengers.

Molecules

________ important in cell signaling first evolved in prokaryotes.

Information

________ is relayed by the G protein to a second messenger, an intracellular signaling molecule.

Cyclic AMP

________ is a second messenger that activates certain protein kinase enzymes that phosphorylate certain proteins.

expression of specific genes

These receptors are transcription factors that activate or repress the ________.

IP3

________ binds to calcium channels in the endoplasmic reticulum, which causes the channels to open and release calcium ions into the cytosol.

G proteins

________, protein kinases, and phosphatases have been highly conserved and are part of most signaling pathways.

Signal termination

________ is the process of inactivating the receptor and each component of the signal transduction pathway once they have done their jobs.

adenylyl cyclase

When certain G proteins undergo a conformational change, they bind with and activate ________, an enzyme on the cytoplasmic side of the plasma membrane.

IP3

________ is a second messenger that can donate phosphate groups to proteins.

Ion channel

________- linked receptors convert chemical signals into electrical signals.

G protein

A(n) ________ consists of three subunits.

tyrosine kinases

Many enzyme- linked receptors are ________, enzymes that phosphorylate proteins.

Intracellular receptors

________ are located in the cytosol or in the nucleus.