BIOL-1230 Cell Communication

Which of the following would most likely diffuse across a synapse?

• insulin

• NO

• histamine

• acetlycholine

• prostaglandins

Hormones produced by endocrine glands are typically transported to target cells:

• across a synapse

• in the blood

• in interstitial fluid

• via direct contact

• through the air

A receptor on the cell surface usually has serveral domains. The function of the external domain is:

• transmitting the signal to the inside of the cell

• holding the recptor within the membrane

• attaching the receptor to the DNA

• functioning as an enzyme

• binding the signaling molecule

Under which of the following situations would receptor down-regulation most likely occur?

• The concentration of a neurotransmitter is too low

• The concentration of a hormone is too high

• The number of recptors in the plasma membrane is too low

• The number of G proteins is too high

• The cell is unable to manufacture cyclic AMP

Tags

NGSS.HS-LS1-3

The other part of a G protein receptor binds________, and its inner part binds___________

• the signaling molecule; tyrosine kinase

• the signaling molecule; a G protein

• G protein; tyrosine kinase

• G protein; an ion channel

• an ion channel; a G protein

Which of the following statements concerning intracellular receptors is FALSE?

• Their ligands are hydrophobic

• Most are transcription factors

• Some are located in the cytosol

• After binding their ligand, they move out of the cell

• Some are bound to DNA

A molecule that is a first messenger but not a second messenger is:

• cyclic AMP

• G protein

• adenylyl cyclase

• protein kinase

• acetylcholine

Adenylyl cyclase is activated directly by:

• a G protein subunit bound to GTP

• a G protein subunit bound to GDP

• cAMP

• a protein kinasee

• a hormone

A protein kinase catalyzes the reaction in which:

• a protein loses a phosphate group

• a protein is phosphorylated

• G protein is activated

• ATP is converted to cAMP

• GTP is converted to GDP

In the cAMP signal transduction pathway, once a protein kinase is activated, which of the following happens next?

• G protein is activated

• Adenylyl clclase is activated

• GDP is replaced by GTP

• cAMP is converted to ATP

• the protein kinase activates a cellular response