Chapter 4.2

Neurotransmitters and neurohormones both: A.Are released by neurons B. Affect only cells with the "specific" receptor for it C. Travel in the blood to their target cell C only A & B A, B & C A only B only

A, B & C

All the following are examples of cellular effects of chemical signals EXCEPT: Activate paratid enyzmes Alter membrane permeability Activate or inhibit enzymes Direct protein synthesis through activation of transcription factors Stimulate cell division

Activate paratid enyzmes

All the following are examples of cellular effects of chemical signals EXCEPT:

Activate paratid enzymes

Lipophilic hormones: Bind to receptors on the surface of the cell Bind to intracellular receptors in the cytoplasm or nucleus Function by activating cAMP Function by way of a second messenger system Cannot diffuse through the cell membrane

Bind to intracellular receptors in the cytoplasm or nucleus

Which of the following cell communication mechanisms would be considered a long-range (distant) regulator? Neurotransmitter Autocrine Hormone Gap junction Paracrine

Hormone

Which of the following cell communication mechanisms would be considered a long-range (distant) regulator? Paracrine Gap junction Neurotransmitter Autocrine Hormone

Hormone

Which statement regarding the formation of the secondary messenger cyclic AMP is INCORRECT?

IP3 binds to receptors on the endoplasmic reticulum

Intracellular receptors are utilized by _________ hormones, while membrane-bound receptors are utilized by _________ hormones. Peptides; steroids Proteins, amines Water soluble; lipid soluble Lipid soluble; water soluble

Lipid soluble; water soluble

Which type of hormone requires a carrier protein in the blood, such as albumin?

Lipid-soluble hormone

Chemicals secreted by one cell that diffuse to affect adjacent cells are considered: Autocrine signals Hormones Paracrine signals Secondary messengers Neurohormones

Paracrine signals

Which hormone group is initially derived from a cholesterol backbone?

Steroids

Which of the following is FALSE about hormones:

They are all steroids

Hormones and neurohormones both: Are released by neurons Travel in the blood to their target cell Are considered local regulators All of the above

Travel in the blood to their target cell

A protein kinase is an enzyme that adds a phosphate to its substrate. False True

True

A G protein linked receptor is a second messenger activated by a steroid hormone. a receptor for a water-soluble hormone that causes arachidonic acid to be extracted from a phospholipid. a molecule that spans the membrane and helps transduce a signal inside a target cell. a type of water-soluble hormone. an enzyme that catalyzes the conversion of ATP into cyclic AMP.

a molecule that spans the membrane and helps transduce a signal inside a target cell.

Autocrine signals:

affect the same cells that secrete them

Eicosanoids are synthesized from

arachidonic acid.

Paracrines:

are local chemical mediators whose effect is exerted on neighboring cells

Lipid-soluble hormones, such as progesterone, exert their effects by forming hormone-receptor complexes that activate a G protein and second-messenger cascade. open ion channels in the cell membrane. activate adenylate cyclase. bind to DNA and initiate transcription.

bind to DNA and initiate transcription.

Inositol triphosphate (IP3):

binds to the calcium channel of the endoplasmic reticulum

Which of the following secondary messengers activates protein kinase A? cAMP IP3 Ca2+ Adenylate cyclase

cAMP

In some second messenger mechanisms calcium is released from the endoplasmic reticulum and binds to __________ . They form a complex which activates other enzyme systems to bring about a cellular response. adenylyl cyclase IP3 cyclic AMP G proteins calmodulin

calmodulin

Which of the following would NOT rely on extracellular chemical messengers for cell-to-cell communication to occur? blood transported signals synaptic signaling cell to cell recognition None of the choices are correct paracrine signaling

cell to cell recognition

Steroid hormones are lipids, derived from glycerol. nucleic acids. polypeptides. cholesterol. amines

cholesterol.

Steroid hormones are lipids, derived from glycerol. polypeptides. amines nucleic acids. cholesterol.

cholesterol.

Intracellular signaling pathways within target cells are organized such that each step involves one molecule activating or synthesizing exactly one other molecule for precise control and linear communication without amplification. enzymes are used up and degraded after each individual reaction they catalyze. each step allows for amplification of the signal where one molecule can activate many.

each step allows for amplification of the signal where one molecule can activate many.

Which of the following allows direct cytoplasmic transfer of electrical or chemical signals between adjacent cells? gap junctions long-distance communication hormones autocrines receptor recognition

gap junctions

Which of the following is NOT an example of a secondary messenger?

insulin

Lipophilic hormones bind to ___________ receptors of target cells.

intracellular

Lipophilic hormones bind to ___________ receptors of target cells. and activates IDP3 and activates 3IPI membrane-bound intracellular

intracellular

When a chemical messenger helps initiate an inflammatory response by causing cellular changes in neighboring cells, it is demonstrating ___________ signaling.

paracrine

Which of the following would NOT rely on extracellular chemical messengers for cell-to-cell communication to occur?

paracrine signaling

In the signal transduction pathway that results in the formation of inositol triphosphate (IP3), the G protein directly activates phospholipase C. calmodulin. protein kinase A. adenylate cyclase.

phospholipase C.

Cyclic AMP activates

protein kinase A

Within the adenylate (adenylyl) cyclase signal transduction pathways of target cells, cAMP activates

protein kinase.

Cortisol is derived from cholesterol, therefore it belongs to the category of hormones called ___________. Cortisol is a lipid soluble hormone, therefore it would bind to a(n) __________ receptor mechanism. steroids; intracellular steroid; membrane bound amines; intracellular peptides; secondary

steroids; intracellular

When the effects of water-soluble hormones on their target cells are considered, the hormone itself is the phospholipase. the hormone-response element. the second messenger. the first messenger. the G protein.

the first messenger.

An enzyme that is described as a protein kinase is a transferase that transfers a phosphate group to a protein substrate. protease that transfers electrons from one protein to another. ligase that adds an amino acid to a protein. isomerase that changes one protein into another. hydrolase that removes an amino acid from a protein.

transferase that transfers a phosphate group to a protein substrate.

Protein hormones are

water-soluble

​What term refers to any enzyme that transfers a phosphate group from ATP to a particular intracellular protein? ​cytokinin ​ATP-ase ​cytosine ​phosphatase ​protein kinase

​protein kinase